Comtech EF Data Vipersat CDD-562L, Vipersat CDD-56 Series, Vipersat CDD-564, Vipersat CDD-564L User Manual
Vipersat CDD-56X Series
Satellite Network Demodulator Router
User Guide
CDD-562L
CDD-564/564L
Part Number 22137 Revision 2.1
Vipersat CDD-56X Series
CDD-562L, CDD-564/564L
Version 1.5.x
User Guide
January 30, 2007
Part number 22137
Document Revision 2.1
Firmware Version 1.5.x
COMTECH EF DATA
VIPERSAT Network Products Group
3215 Skyway Court
Fremont, CA 94539
USA
Phone: (510) 252-1462
Fax: (510) 252-1695
www.comtechefdata.com
Part Number 22137
Manual Revision 2.0
Firmware Version 1.5.x
©2006 by Comtech EF Data, Inc. All rights reserved. No part of this manual
may be copied or reproduced without prior written permission of Comtech EF
Data, Inc.
Comtech reserves the right to revise this publication at any time without
obligation to provide notification of such revision. Comtech periodically revises
and improves its products and, therefore, the information in this document is
subject to change without prior notice. Comtech makes no warranty of any kind
with regard to this material, including but not limited to the implied warranties
of mechantability and fitness for a particular purpose. No responsibility for any
errors or omissions that may pertain to the material herein is assumed. Comtech
makes no commitment to update nor to keep current the information contained
in this document.
All products, names, and services are trademarks or registered trademarks of
their respective companies.
Printed in the United States of America
Document Revision Status
Document
Revision
Date Description Affected Pages
Rev. 1.0 9/20/05 Initial release of document N/A
Rev. 2.0 6/12/06 Revisions for firmware version 1.5.3 All
Rev. 2.1 1/30/07 Content updates; Logo change Misc.
{ This Page is Intentionally Blank }
i
General
How to Use This Manual . . . . . . . . . . . 1-1
Manual Organization . . . . . . . . . . . . 1-1
Chapter 1 — General . . . . . . . . . 1-1
Chapter 2 — Quick Start Configuration 1-1
Chapter 3 — Using the Command Line
Interface (CLI) . . . . . . . . . . . . 1-2
Appendix A — Network Addressing . . 1-2
Appendix B — Automatic Switching . . 1-2
Appendix C — Dynamic Power Control1-2
Appendix D — Network Migration . . . 1-2
Appendix E — Glossary . . . . . . . . 1-2
Conventions and References . . . . . . . . 1-2
Product Description . . . . . . . . . . . . . . 1-4
Introduction . . . . . . . . . . . . . . . 1-4
Demodulator Features . . . . . . . . . . 1-4
Router Features . . . . . . . . . . . . . 1-4
Network and Bandwidth Management . . 1-5
Dynamic SCPC (dSCPC) . . . . . . . . 1-5
STDMA . . . . . . . . . . . . . . . . . 1-6
Single Hop On Demand . . . . . . . . . 1-6
Turbo Product Coding . . . . . . . . . . 1-6
Header Decompression . . . . . . . . . 1-6
Payload Decompression. . . . . . . . . 1-7
Data Decryption . . . . . . . . . . . . . 1-7
New in This Release. . . . . . . . . . . . . 1-7
1.5.3 Release . . . . . . . . . . . . . . 1-7
New Redundancy Features . . . . . . 1-7
New QoS Features . . . . . . . . . . 1-7
Burst Fast Acquisition Timing (BFAT). 1-8
STDMA Slot Quantization . . . . . . . 1-8
RTP Inactivity Timeout. . . . . . . . . 1-8
Parameter File Consolidation . . . . . 1-8
Vipersat File Streaming (VFS) . . . . 1-8
Automatic Home State Control (Remote
Unit) . . . . . . . . . . . . . . . . . 1-8
ECM User Defined Switch Type . . . . 1-9
Customer Support . . . . . . . . . . . . . . . 1-10
Contact Information . . . . . . . . . . 1-10
Return Material Authorization . . . . . 1-10
Reader Comments / Corrections . . . 1-10
Quick Start Configuration
Introduction . . . . . . . . . . . . . . . . . . 2-1
Initial Configuration . . . . . . . . . . . . . . 2-2
Terminal Connection . . . . . . . . . . 2-2
Network Role . . . . . . . . . . . . . . . . 2-2
Setting Vipersat CDD-56X Operating
Parameters. . . . . . . . . . . . . . . . . 2-3
Set the Feature Configuration. . . . . . 2-3
Set the IP Address . . . . . . . . . . . 2-6
Configure the Route Table . . . . . . . 2-7
Routing in a Vipersat Network. . . . . 2-7
Creating the Routes . . . . . . . . . . 2-8
Set the Satellite Demod Configuration . 2-9
Set the Vipersat Configuration . . . . 2-10
Using the Command Line Interface
(CLI)
General . . . . . . . . . . . . . . . . . . . . . 3-1
Common Screen Commands . . . . . . . . 3-2
Demod Select . . . . . . . . . . . . . . 3-2
Save Parameters to Permanent Storage 3-2
Exit . . . . . . . . . . . . . . . . . . . 3-2
Telnet Logout . . . . . . . . . . . . . . 3-2
Menu Descriptions . . . . . . . . . . . . . . . 3-3
Main Menu . . . . . . . . . . . . . . . . . 3-3
Administration . . . . . . . . . . . . . . 3-3
Feature Configuration . . . . . . . . . . . . 3-4
Vipersat Feature Codes . . . . . . . . . 3-5
Vipersat Management . . . . . . . . . . 3-6
Vipersat STDMA . . . . . . . . . . . . 3-6
Vipersat Auto Switching . . . . . . . . . 3-6
Vipersat File Streamer. . . . . . . . . . 3-6
Vipersat Configuration . . . . . . . . . . . . . 3-8
STDMA Mode . . . . . . . . . . . . . . . . 3-8
STDMA . . . . . . . . . . . . . . . . 3-10
STDMA Tx Rate. . . . . . . . . . . . 3-10
Hub Type . . . . . . . . . . . . . . . 3-10
1 – Fixed . . . . . . . . . . . . . . 3-11
2 – Dynamic Slot . . . . . . . . . . 3-11
3 – Dynamic Cycle . . . . . . . . . 3-11
4 – GIR . . . . . . . . . . . . . . . 3-11
5 – Entry Channel . . . . . . . . . . 3-12
Group ID. . . . . . . . . . . . . . . . 3-12
Low Data Rate Fast Acquisition . . . . 3-13
Burstmap Multicast IP . . . . . . . . . 3-13
Outbound IP. . . . . . . . . . . . . . 3-14
Cycles Per Burst Map . . . . . . . . . 3-14
Slot Guardband . . . . . . . . . . . . 3-15
Table of Contents
ii Vipersat CDD-56X Series User Guide
Slot Preamble Length . . . . . . . . . 3-15
Slot Data Length. . . . . . . . . . . . 3-16
Nominal Data Length . . . . . . . . . 3-17
Maximum Data Length. . . . . . . . . 3-17
Minimum Data Length . . . . . . . . . 3-18
Slot Cycle Length . . . . . . . . . . . 3-18
Slot Start in Cycle . . . . . . . . . . . 3-19
Set Remotes. . . . . . . . . . . . . . 3-19
Adding a Remote to the STDMA Group .
3-19
Base . . . . . . . . . . . . . . . . . 3-20
Remote Count . . . . . . . . . . . . 3-21
Set Remote Policies . . . . . . . . . 3-21
Delete Remote. . . . . . . . . . . . 3-23
Enable/Disable Remote . . . . . . . 3-24
View Remote(s) . . . . . . . . . . . 3-24
Remove Timeout . . . . . . . . . . 3-25
Remove Retry Timeout . . . . . . . 3-25
STDMA Statistics . . . . . . . . . . . 3-26
Stats Accumulation Window . . . . . 3-27
Clear . . . . . . . . . . . . . . . . . 3-27
Show Hub Statistics . . . . . . . . . . 3-27
STDMA/SCPC Automatic Switching. . . . 3-29
Auto Switching a Hub CDD-56X . . . . 3-29
Auto Switching . . . . . . . . . . . . 3-30
Current WAN Transmit Mode . . . . 3-30
Load Switching . . . . . . . . . . . 3-30
STDMA Slot Capacity . . . . . . . . 3-31
STDMA Switch Delay . . . . . . . . 3-31
Percent Allocation . . . . . . . . . . 3-32
Time for Carrier Inhibit . . . . . . . . 3-32
Unit Role. . . . . . . . . . . . . . . . . . 3-33
Expansion Unit . . . . . . . . . . . . . . 3-33
Network ID. . . . . . . . . . . . . . . . . 3-34
Unit Name . . . . . . . . . . . . . . . . . 3-34
Receive Multicast Address . . . . . . . . 3-35
Managing IP Address . . . . . . . . . . . 3-36
Primary Heart Beat . . . . . . . . . . . . 3-36
Home State Revert . . . . . . . . . . . . 3-36
Dynamic Power Control Configuration . . 3-37
DPC Enabled . . . . . . . . . . . . . 3-38
Speed Up EbNo . . . . . . . . . . . . 3-39
Target DPC Address. . . . . . . . . . 3-39
Set Home State Parameters. . . . . . . . 3-40
Set Current Configuration as Home State .
3-41
Force Modem to Home State . . . . . 3-41
STDMA State . . . . . . . . . . . . . 3-41
Receive Frequency . . . . . . . . . . 3-42
Receive Data Rate . . . . . . . . . . 3-42
Receive FEC Type . . . . . . . . . . 3-43
Receive Coding Rate . . . . . . . . . 3-43
Receive Modulation Type . . . . . . . 3-43
Vipersat Summary . . . . . . . . . . . . 3-44
Vipersat Migration. . . . . . . . . . . . . 3-45
APPENDICES
Network Addressing
Introduction . . . . . . . . . . . . . . . . . . A-1
The OSI Reference Model . . . . . . . . . . A-2
Layers 1 – 3 . . . . . . . . . . . . . . . . . A-2
Binary Math . . . . . . . . . . . . . . . . . . A-4
IP Addressing . . . . . . . . . . . . . . . . . A-6
IP Address Classes . . . . . . . . . . . . . A-6
Class A . . . . . . . . . . . . . . . . A-6
Class B . . . . . . . . . . . . . . . . A-6
Class C . . . . . . . . . . . . . . . . A-7
Class D . . . . . . . . . . . . . . . . A-7
Class E . . . . . . . . . . . . . . . . A-8
Private Network IP Addresses . . . . . A-8
Network Address Translation (NAT). . . A-8
Subnets . . . . . . . . . . . . . . . . . . . A-8
Subnet Mask . . . . . . . . . . . . . . . . A-9
Network Segments . . . . . . . . . . . . A-10
Default Gateways . . . . . . . . . . . . . A-11
MAC Addresses. . . . . . . . . . . . . . A-11
Automatic Switching
General . . . . . . . . . . . . . . . . . . . . B-1
Bandwidth Allocation and Load Switching . B-2
Load Switching . . . . . . . . . . . . . . . . B-3
Bandwidth Allocation and Load Switching by
the STDMA Controller . . . . . . . . . B-3
Load Switching Process. . . . . . . . . B-6
Load Switching by a Remote . . . . . . B-7
Determining Need-for-Change . . . . . B-8
Load Switch Example . . . . . . . . . . . . B-8
Reduced Data Flow in Switched Mode
(SCPC) . . . . . . . . . . . . . . . B-10
Application Switching . . . . . . . . . . . . . B-11
Type of Service (ToS) Switching . . . . . . . B-13
Entry Channel Mode (ECM) Switching . . . . B-14
Fail-Safe Operation . . . . . . . . . . . . B-14
Dynamic Power Control
iii
Introduction . . . . . . . . . . . . . . . . . . C-1
Description. . . . . . . . . . . . . . . . . .C-2
Adjustment for Data Rate . . . . . . .C-3
DPC Scaling Function . . . . . . . . .C-4
Network Migration
General . . . . . . . . . . . . . . . . . . . . D-1
Firmware Upgrade. . . . . . . . . . . . . . . D-3
Upgrade Overview. . . . . . . . . . . . . .D-3
Required Support Utilities and Firmware D-3
Basic Steps . . . . . . . . . . . . . . .D-3
Migration Procedure . . . . . . . . . . . . .D-4
Configure Upgrade Image . . . . . . . .D-4
Getting Information with VLOAD. . . . .D-5
Upgrade Router to v1.5.3 . . . . . . . .D-7
Save and Reboot to Latest . . . . . . .D-9
Get Information for Router v1.5.3 . . . D-11
Upgrade Base Modem to v1.5.1 (CDM-570
Only). . . . . . . . . . . . . . . . . D-12
Upgrade Image 1 on Base Modem to
v1.4.5 . . . . . . . . . . . . . . . D-12
Upgrade Image 1 on Base Modem to
v1.5.1 . . . . . . . . . . . . . . . D-13
Download Base Modem v1.5.1 to Image 2 .
D-14
Download Router v1.5.3 to Image 2. . D-15
Completing Migration . . . . . . . . . . . D-16
Picking Up Straggler/Offline Remotes. D-16
Setting v1.5.2 Compatibility in Hub Modems
D-16
Glossary
iv Vipersat CDD-56X Series User Guide
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v
Chapter 2 Figures
Figure 2-1 Main Menu screen. . . . . . . . . . . . . . 2-4
Figure 2-2 Administration screen . . . . . . . . . . . 2-4
Figure 2-3 Feature Configuration screen . . . . . 2-5
Figure 2-4 Feature and Unlock Code dialog. . . 2-5
Figure 2-5 Working Mode dialog . . . . . . . . . . . 2-6
Figure 2-6 Ethernet Interface screen . . . . . . . . 2-7
Figure 2-7 Configuring the Route Table screen 2-9
Figure 2-8 Rx Configuration screen . . . . . . . . 2-10
Figure 2-9 Vipersat Configuration screen (Hub). .
2-11
Chapter 3 Figures
Figure 3-1 Main Menu screen. . . . . . . . . . . . . . 3-3
Figure 3-2 Administration screen . . . . . . . . . . . 3-4
Figure 3-3 Feature Configuration screen . . . . . 3-4
Figure 3-4 Feature and Unlock Code dialog. . . 3-5
Figure 3-5 Vipersat Configuration screen (Hub)3-8
Figure 3-6 STDMA screen (Hub, STDMA, Fixed
type). . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-9
Figure 3-7 STDMA screen (Hub/Remote, SCPC)
3-9
Figure 3-8 Hub Type prompt . . . . . . . . . . . . . 3-10
Figure 3-9 Group ID prompt . . . . . . . . . . . . . . 3-13
Figure 3-10 Burstmap Multicast IP prompt . . . 3-14
Figure 3-11 Outbound IP prompt . . . . . . . . . . 3-14
Figure 3-12 Cycles per Burst Map prompt . . . 3-15
Figure 3-13 Slot Guardband prompt. . . . . . . . 3-15
Figure 3-14 Slot Preamble Length prompt . . . 3-16
Figure 3-15 Slot Data Length prompt . . . . . . . 3-16
Figure 3-16 Nominal Data Length prompt . . . 3-17
Figure 3-17 Maximum Data Length prompt . . 3-18
Figure 3-18 Minimum Data Length prompt. . . 3-18
Figure 3-19 STDMA Remotes Menu screen . 3-19
Figure 3-20 Remote Name and IP Address prompt
3-20
Figure 3-21 Base Remote Display prompt . . . 3-21
Figure 3-22 STDMA Remote Policies screen (GIR
Hub) . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-21
Figure 3-23 GIR Remote Policies prompt. . . . 3-22
Figure 3-24 Entry Channel Switch Rates screen .
3-22
Figure 3-25 Remote SCPC Data Rate prompt3-23
Figure 3-26 Global SCPC Data Rate prompt .3-23
Figure 3-27 Global Switch Type prompt . . . . .3-23
Figure 3-28 Delete Remote prompt . . . . . . . .3-24
Figure 3-29 Enable/Disable Remote prompt .3-24
Figure 3-30 View Remote(s) screen . . . . . . . .3-24
Figure 3-31 Remove Timeout prompt . . . . . . . 3-25
Figure 3-32 Remove Retry Timeout prompt . .3-25
Figure 3-33 STDMA Statistics screen (Hub). .3-26
Figure 3-34 STDMA Statistics screen (Remote). .
3-27
Figure 3-35 Stats Accumulation Window prompt .
3-27
Figure 3-36 Show Hub Statistics screen. . . . . 3-28
Figure 3-37 Automatic Switching screen . . . .3-30
Figure 3-38 STDMA Slot Capacity prompt . . .3-31
Figure 3-39 STDMA Switch Delay prompt . . . 3-32
Figure 3-40 Percent Allocation prompt . . . . . .3-32
Figure 3-41 Unit Role prompt . . . . . . . . . . . . .3-33
Figure 3-42 Expansion Unit prompt . . . . . . . .3-33
Figure 3-43 Network ID prompt . . . . . . . . . . .3-34
Figure 3-44 Unit Name prompt . . . . . . . . . . . .3-35
Figure 3-45 Receive Multicast IP Address prompt
3-35
Figure 3-46 Managing IP Address prompt . . . 3-36
Figure 3-47 DPC Configuration screen (Hub,
STDMA) . . . . . . . . . . . . . . . . . . . . . . . .3-38
Figure 3-48 DPC Configuration screen (Hub/
Remote, SCPC) . . . . . . . . . . . . . . . . . .3-38
Figure 3-49 Speed Up EbNo prompt . . . . . . .3-39
Figure 3-50 Target DPC Address prompt . . . .3-40
Figure 3-51 Home State Configuration screen3-40
Figure 3-52 Force Modem to Home State warning
3-41
Figure 3-53 Receive Frequency prompt . . . . .3-42
Figure 3-54 Receive Data Rate prompt . . . . .3-42
Figure 3-55 Receive FEC Type prompt . . . . . 3-43
Figure 3-56 Receive Coding Rate prompt . . .3-43
Figure 3-57 Receive Modulation Type prompt 3-44
Figure 3-58 Vipersat Summary screen . . . . . .3-44
Figure 3-59 Vipersat Migration prompt . . . . . .3-45
List of Figures
vi Vipersat CDD-56X Series User Guide
Appendix A Figures
Figure A-1 The Seven OSI Protocol Layers . . .A-2
Figure A-2 Bits and Bytes. . . . . . . . . . . . . . . . .A-4
Figure A-3 Binary to Decimal Conversion . . . .A-4
Figure A-4 IP Address Classes A, B, C . . . . . .A-7
Figure A-5 NAT Router Example . . . . . . . . . . .A-8
Figure A-6 Default Subnet Masks for IP Classes .
A-9
Figure A-7 ANDing an IP address and a subnet
mask . . . . . . . . . . . . . . . . . . . . . . . . . .A-10
Figure A-8 Network Segments . . . . . . . . . . . .A-10
Figure A-9 Router as Default Gateway. . . . . .A-11
Figure A-10 Network Node MAC Addresses .A-12
Appendix B Figures
Figure B-1 Auto Switching menu (Hub) . . . . . .B-5
Figure B-2 Auto Switching menu (Remote) . . . B-7
Figure B-3 Load Switching diagram . . . . . . . . .B-9
Figure B-4 Application Switching diagram . . .B-11
Figure B-5 ECM Switch Recovery: < 3 minutes . .
B-15
Figure B-6 ECM Switch Recovery: > 3 minutes . .
B-16
Appendix C Figures
Figure C-1 DPC Scaling Function . . . . . . . . . .C-4
Appendix D Figures
Figure D-1 Firmware Migration Stages—CDM-570
D-4
Figure D-2 Main Menu, Telnet . . . . . . . . . . . . D-5
Figure D-3 Operations and Maintenance MenuD-5
Figure D-4 Initial Vload screen . . . . . . . . . . . . D-6
Figure D-5 Add All dialog . . . . . . . . . . . . . . . . D-6
Figure D-6 Get Information for IP Address . . . D-7
Figure D-7 Put Application screen (Consecutive
Load) . . . . . . . . . . . . . . . . . . . . . . . . . . D-8
Figure D-8 Progress Status, Put Application . D-9
Figure D-9 Hard Reset screen . . . . . . . . . . . D-10
Figure D-10 Progress Status, Put CompletionD-10
Figure D-11 Unit Information screen (Router) D-11
Figure D-12 Select Configuration screen . . . D-11
Figure D-13 Configuration File Text . . . . . . . D-12
Figure D-14 Browse for Firmware File . . . . . D-12
Figure D-15 Download v1.4.5 and Hard Reset
screen . . . . . . . . . . . . . . . . . . . . . . . . D-13
Figure D-16 Unit Information screen (Base Modem
Image 1). . . . . . . . . . . . . . . . . . . . . . . D-13
Figure D-17 Download v1.5.1 and Hard Reset
screen . . . . . . . . . . . . . . . . . . . . . . . . D-14
Figure D-18 Unit Information screen (Base Modem
Image 2). . . . . . . . . . . . . . . . . . . . . . . D-14
Figure D-19 Unit Information screen (Base Modem
v1.5.1) . . . . . . . . . . . . . . . . . . . . . . . . D-15
Figure D-20 Unit Information screen (final status)
D-15
Figure D-21 Main Menu screen, CLI. . . . . . . D-16
Figure D-22 Vipersat Configuration screen . D-17
Figure D-23 Vipersat Migration prompt. . . . . D-17
vii
Chapter 2 Tables
Table 2-1 CDD-56X Network Roles and Functions
2-3
Table 2-2 Vipersat Feature Configuration . . . . 2-6
Appendix B Tables
Table B-1 STDMA ACK Message . . . . . . . . . .B-3
Appendix C Tables
Table C-1 Dynamic Power Control ParametersC-2
List of Tables
viii Vipersat CDD-56X Series User Guide
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Chapter 1 - General 1-1
C
HAPTER
GENERAL
How to Use This Manual
This manual documents the enhanced Vipersat features and functions of the
CDD-56X Series (CDD-562L, CDD-564, and CDD-564L) of Satellite Network
Demodulator Routers, and guides the user in how to configure these products
for use in a Vipersat network. The material covered addresses only those areas
specific to a CDD-56X running in Vipersat mode, and complements the universal features and functions described in the CDD-564L Installation and Opera-
tion Manual.
Earth station engineers, technicians, and operators responsible for the configuration and maintenance of the CDD-56X are the intended audience for this
document.
Manual Organization
This User’s Guide is organized into the following sections:
Chapter 1 — General
Contains CDD-56X product description, customer support information, and
manual conventions and references.
Chapter 2 — Quick Start Configuration
Covers the initial basic steps that are necessary for configuring the CDD-56X
from a factory default state to a functional network element.
How to Use This Manual
1-2 Vipersat CDD-56X Series User Guide
Chapter 3 — Using the Command Line Interface (CLI)
Describes the use of the CLI for configuring and monitoring the CDD-56X in a
Vipersat network. Each CLI screen is presented along with a detailed description and related commands.
Appendix A — Network Addressing
Supplemental reference information on binary math and network addressing to
assist with integrating the CDD-56X into a Vipersat network.
Appendix B — Automatic Switching
Supplemental reference information on the Vipersat feature that provides load
switching (response to network traffic load), application switching (response to
traffic type) functions, and Entry Channel Mode switching functions.
Appendix C — Dynamic Power Control
A description of Vipersat’s DPC and its relationship to a CDD-56X configuration.
Appendix D — Network Migration
Procedural instructions for upgrading a network of CDM-570/CDD-56X series
modems to firmware version 1.5.3.
Appendix E — Glossary
A glossary of terms that pertain to Vipersat satellite network technology.
Conventions and References
The following conventions are utilized in this manual to assist the reader:
Note: Provides important information relevant to the accompanying
text.
Tip: Provides complementary information that facilitates the
associated actions or instructions.
Caution: Explanatory text that notifies the reader of possible
consequences of an action.
NOTE
Chapter 1 - General 1-3
How to Use This Manual
The following documents are referenced in this manual, and provide supplementary information for the reader:
• CDD-564L L-Band Quad Demodulator with IP Module Installation and
Operation Manual (Part Number MN/CDD564L.IOM)
• Vipersat Management System User Guide (Part Number 22156)
• Vload Utility User Guide (Part Number 22117)
Product Description
1-4 Vipersat CDD-56X Series User Guide
Product Description
Introduction
The Vipersat CDD-56X Satellite Network Demodulator Router is ideal for
operators wishing to supply mesh connectivity between sites, while keeping
network infrastructure costs down. The CDD-564 and CDD-564L provide four
separate demodulators (the CDD-562L provides two) and an integrated router in
a compact, cost-effective 1RU package.
The CDD-56X simplifies Hub site installations by reducing rack space and cost
with 2/4 independent demodulators in a single chassis. A bank of CDD-56X
demodulators is ideal for a star network consisting of a single outbound carrier
at the Hub with multiple carriers returned from the remote sites.
The CDD-56X can be used at Hub sites where multiple burst controllers are
needed. Demodulator roles are defined via software, configurable either as a
burst controller in STDMA (Selective Time Division Multiple Access) mode, or
as dedicated SCPC (Single Channel per Carrier) inbounds from remote terminals.
At remote sites, the CDD-56X supports mesh connectivity between multiple
sites. Operating in mesh topology with links directly between sites eliminates
double-hops through the Hub, conserving bandwidth and reducing latency.
Demodulator Features
• 50–90 MHz or 100–180 MHz IF Range, each Demodulator (CDD-564)
950–1950 MHz IF Range, each Demodulator (CDD-562L/564L)
• QPSK, 8-PSK, and 16-QAM Operation
• Data Rate Range from 16 kbps up to 9.98 Mbps, depending on modulation
and FEC used (with FAST feature upgrade)
• Turbo Product Coding (TPC) FEC
• Fast Acquisition Demodulator
• Simultaneous STDMA (burst) and dSCPC modes (configurable on a per
demodulator basis)
• LNB Support: 10 MHz Reference and LNB Power
• N:M Hub Modem Redundancy Schemes
Router Features
• Fully Integrated Network Management using Vipersat Management
System (VMS)
Chapter 1 - General 1-5
Product Description
• Single Hop On Demand (SHOD) functions
• 10/100BaseT Ethernet LAN/WAN Interface
• Static IP Routing for Unicast or Multicast
• Header Decompression
• Payload Decompression
• 3xDES Decryption
Network and Bandwidth Management
A Vipersat-powered network solution integrates this advanced demodulator/
router with the powerful network management tool, the Vipersat Management
System (VMS). The VMS provides for traditional monitor and control of the
CDM-570/570L modems and the CDD-56X demodulators, but more than just
an M&C package, the VMS allows these units to share bandwidth, and when
needed, switch automatically to a dedicated SCPC channel.
Dynamic SCPC (dSCPC)
The VMS provides for dynamic bandwidth allocation while in SCPC mode,
automatically altering the bandwidth based on traffic conditions. This effectively enables the network to better handle connection-oriented applications and
reduce network congestion, jitter, and latency.
In a typical Vipersat application used in conjunction with CDM-570/570L
modems, the CDD-56X demodulators are drawn from a pool for assignment to a
connection-oriented link.
Traffic inbounds from remotes can be switched manually or automatically,
application or load triggered, or scheduled, from shared STDMA (burst) mode
to a dedicated SCPC connection. The VMS automatically assigns a free demodulator at the Hub to a desired remote inbound, completely eliminating manual
intervention. At remote sites, the CDD-56X simplifies Single Hop On Demand
(SHOD) applications with direct remote-to-remote connections that do away
with double-hops. Once the session is completed, the remote is automatically
reverted back to its home state.
In addition, the CDD-56X simplifies Single Hop On Demand (SHOD) applications with direct remote-to-remote connections that do away with double-hops.
The result is an economical and flexible network with bandwidth shared and
directed where it is needed for any mix of IP voice, video, and data traffic.
Product Description
1-6 Vipersat CDD-56X Series User Guide
STDMA
The addition of STDMA capability to a Vipersat network allows multiple terminals to share the same satellite resources that would be dedicated to a single
terminal in an SCPC configuration. This means that more terminals can be
added to the network with minimal additional cost in either satellite bandwidth
or Hub Terminal hardware.
Vipersat STDMA thus provides a low cost solution for medium to large sized
networks with generally moderate bandwidth requirements, while at the same
time providing all the features of the existing Vipersat systems, including the
availability of a switched pool of SCPC channels for occasional high bandwidth
traffic such as video conferences and large file transfers. Each STDMA
upstream channel from the remote terminals to the Hub uses an STDMA frame
operating at an aggregate data rate of from 16 kbps to 9.98 Mbps and can
support up to hundreds of remote terminals with multiple burst channel
inbounds.
Configured as a Hub terminal, the CDD-564/564L provides one demod for
receiving an upstream STDMA channel from the remotes, and three demods for
receiving three SCPC channels.
Single Hop On Demand
The CDD-56X is ideal for mesh applications such as Vipersat's Single Hop On
Demand (SHOD). With the CDD-56X, SHOD (meshed) circuits are easily and
economically established between remotes. SHOD provides significant and
dynamic connectivity between latency connections without suffering the high
costs associated with multiple carriers and/or 1-to-1 multi-receiver links.
Turbo Product Coding
The Comtech Vipersat CDD-56X incorporates a Turbo Product Codec (TPC)
error correction, delivering significant performance improvement when
compared to Viterbi with concatenated Reed-Solomon. TPC simultaneously
offers increased coding gain, lower decoding delay, and significant bandwidth
savings.
Header Decompression
Header compression reduces the required Voice over Internet Protocol (VoIP)
bandwidth by as much as 60%. Example: a G.729 voice codec operating at 8
kbps will occupy 32 kbps once encapsulated into IP framing on a LAN. Using
IP/UDP/RTP Header Compression, the same traffic only needs 10.8 kbps total
WAN satellite bandwidth to cross the link. The CDD-56X demods perform
header decompression prior to passing the data onto the LAN.
Chapter 1 - General 1-7
Product Description
Payload Decompression
Payload compression condenses the size of data frames and reduces the satellite
bandwidth required to transmit across the link. Configurable on a per route
basis, Payload Compression provides traffic optimization and reduces bandwidth up to 40%. The CDD-56X demods perform payload decompression prior
to passing the data onto the LAN.
Data Decryption
The CDD-56X decrypts 3xDES data that it receives. Data encryption, configurable on a per route basis, is used to prevent unauthorized access to data over
the satellite link.
New in This Release
The following firmware versions incorporate a number of additional features
and enhancements.
1.5.3 Release
New Redundancy Features
Redundancy Heartbeat Message for Primary Hub Units
Provides the option for a periodic communications check message to be sent
from the Hub modem to the VMS for backup recovery in N:M redundancy
(protected) configurations. This feature allows the message interval to be specified by the administrator, and can be enabled through either the CLI or the
VMS.
New QoS Features
Dynamic Buffering
Reduction of overall system latency is now optimized in the Vipersat network
by dynamic buffering enhancements that provide a minimum buffer size of 2
MB, with a user-specified latency period (five second maximum).
QoS Rule Switching
With QoS Rule Switching, an STDMA to SCPC switch can be initiated based
upon any type of IP traffic flow that matches a defined QoS queue.
Product Description
1-8 Vipersat CDD-56X Series User Guide
Burst Fast Acquisition Timing (BFAT)
The BFAT feature provides dramatic reduction in data acquisition times for
Vipersat modems operating in STDMA (burst) mode at low data rates (64 kbps
to 256 kbps). Preamble size is automatically recalculated and adjusted by the
modem for optimum performance. This feature can be enabled in modems operating at 3/4 QPSK.
STDMA Slot Quantization
Utilizing Turbo FEC Block mode, Vipersat STDMA Slot Quantization automatically sizes the data slot to hold an integral number of FEC blocks, based on the
current data rate. This results in increased STDMA efficiency.
RTP Inactivity Timeout
The timeout period for Real-time Transfer Protocol (e.g., voice, video) data
flows is now set for 10 seconds of inactivity to reduce the wait period until the
next switch state occurs, thus increasing SCPC bandwidth utilization.
Parameter File Consolidation
Configuration parameters for the entire CDM-570/570L modem (base modem
plus IP router module) are now stored in one common parameter file. All
modem parameters are now preserved across firmware upgrades and reboots,
eliminating a potential cause of communications failure.
Vipersat File Streaming (VFS)
The Vipersat File Streaming feature option allows data files to be streamed over
the Vipersat network at high transmission rates between PC hosts running the
VFS application.
Automatic Home State Control (Remote Unit)
VMS communications management of Remote units is now improved with the
Home State Revert feature. By configuring a time value (in minutes) in the
VMS for each Remote in the network, resource recovery is performed on SCPC
connections when a communications failure occurs between the VMS and a
Remote, such as a rain fade condition, a Remote unit power down, or a hardware failure. Should communications be lost for more than the selected time
period, the Remote will automatically revert to its Home State settings and the
VMS will remove all allocated resources (bandwidth, demod(s)), freeing them
for use by any other Remotes in the network.
Chapter 1 - General 1-9
Product Description
ECM User Defined Switch Type
New SCPC switching flexibility is provided by the Entry Channel Mode (ECM)
user-defined policy switch type feature. The STDMA Remote Policies can be
set for the desired SCPC data rate (kbps) and the Switch Type (0=Load, 64-255
range is user-defined).
Customer Support
1-10 Vipersat CDD-56X Series User Guide
Customer Support
Contact Information
Contact Comtech Vipersat Networks Customer Support for information or
assistance with product support, service, or training on any Vipersat product.
Mail: 3215 Skyway Court
Fremont, CA 94539
USA
Phone: 1+510-252-1462
Fax: 1+510-252-1695
Email: support@comtechefdata.com
Web: www.comtechefdata.com
Return Material Authorization
Any equipment returned to Vipersat must have a Return Material Authorization
(RMA) issued prior to return. To return a Comtech Vipersat Networks product
for repair or replacement:
• Obtain an RMA form and number from Vipersat Customer Support.
• Be prepared to supply the product model number and serial number of the
unit.
• To ensure safe shipping of the product, pack the equipment in the original
shipping carton.
Reader Comments / Corrections
If the reader would like to submit any comments or corrections regarding this
manual and its contents, please forward them to a Vipersat Customer Support
representative. All input is appreciated.
Chapter 2 - Quick Start Configuration 2-1
C
HAPTER
QUICK START CONFIGURATION
Introduction
This chapter describes the minimum configuration of a Vipersat CDD-56X
Series Demodulator Router that is necessary in order for the equipment to function in a Vipersat network.
The Vipersat CDD-56X Demodulator Router stores its configuration in an
ASCII file named the PARAM file. Equipment Configuration is typically
performed through the use of the Command Line Interface (CLI), particularly
the initial configuration. Once the equipment is functioning in the network,
additional configuration can be performed via the VMS.
Refer to Chapter 3, “Using the Command Line Interface (CLI)”, for a detailed
description on the usage of this feature.
This manual covers the configuration specifics of the CDD-56X when used in a
Vipersat network. Refer to the CDD-564L L-band Quad Demodulator Installa-
tion and Operation Manual for general instruction on setting up, installing and
configuring this equipment.
Note: Before attempting to configure a CDD-56X to be used in a Vipersat
network, make certain it has the Vipersat option installed and enabled.
NOTE
Initial Configuration
2-2 Vipersat CDD-56X Series User Guide
Initial Configuration
Note: Many of the settings required for equipment configuration are based on
the LAN/WAN and Satellite network design, and should be obtained from
the network administrator.
Terminal Connection
These procedures are performed using the CLI from a workstation connected to
the CDD-56X either via a direct connection to the Console port (a console cable
is shipped with each unit), or via a telnet connection to the Traffic 100 port.
Alternatively, HyperTerminal or any of the other connection methods described
in the CDD-564L L-band Quad Demodulator Installation and Operation
Manual may be used.
Make a terminal connection to the target CDD-56X demodulator/router. If
connecting via the Traffic 100 Ethernet port (do not use the M&C port), enter
the IP address of the unit. The factory default IP address is 192.168.1.1. Configure the terminal for VT-100 emulation mode. Once a terminal connection has
been made, the CDD-56X will respond with a Login prompt. The factory
defaults are:
Login: comtech
Password: comtech
Once the operator has logged in, the Main Menu shown in figure 2-1 is
displayed.
Network Role
The first and most important step prior to configuring the CDD-56X is to define
its network role.
The CDD-56X is a flexible network component able to perform different functions depending on how it is used in a network. The role that is defined for each
CDD-56X will determine what functions are available for each unit to fill its
role. Refer to the section “Unit Role” on page 3-33 for details on setting a
CDD-56X’s network role. Table 2-1 lists the network roles and the corresponding network functions for which the CDD-56X can be configured.
NOTE
Chapter 2 - Quick Start Configuration 2-3
Initial Configuration
Setting Vipersat CDD-56X Operating Parameters
The following is an example of using the CLI to bring a Vipersat CDD-56X
with factory default settings to the configuration which allows the Vipersat
functions to be accessible.
When the parameter file (param image) of the CDD-56X has either been reset
to or still has factory default configuration, all Vipersat feature and unlock
codes in the CDD-56X are deleted and all configurations are reset, disabling the
Vipersat feature set.
Set the Feature Configuration
The operating parameters that will be configured in the target CDD-56X are, in
part, determined by the role the CDD-56X is to fill in the network, as shown in
table 2-1 and table 2-2.
Use the following procedure to configure a CDD-56X to the network role it is to
fill in a Vipersat network.
1. From the Main Menu shown in figure 2-1, select the Administration
command by entering A at the command prompt.
Table 2-1
CDD-56X Network Roles and Functions
Demod
Role / Location Expansion 1 2 3 4
Hub No STDMA SCPC SCPC SCPC
Hub Yes SCPC SCPC SCPC SCPC
Remote Yes SCPC SCPC SCPC SCPC
Initial Configuration
2-4 Vipersat CDD-56X Series User Guide
Figure 2-1
Main Menu screen
2. From the Administration screen shown in figure 2-2, select the Features
Configuration command by entering F at the command prompt.
Figure 2-2
Administration screen
3. From the Feature Configuration menu shown in figure 2-3, verify
whether or not the Vipersat Feature Codes appear as shown in the figure.
These codes are entered prior to shipment from the factory; however, if the
unit has been reset with the Restore Factory Defaults command, the
codes will have to be re-entered. If the Feature Codes are not displayed in
Chapter 2 - Quick Start Configuration 2-5
Initial Configuration
the menu, enter F at the command prompt, then enter the 3 digit Feature
Code followed by the Unlock Code, as shown in figure 2-4.
Figure 2-3
Feature Configuration screen
Figure 2-4
Feature and Unlock Code dialog
Tip: The network administrator will have the Feature and Unlock codes. These
are stored by the MAC address for the target CDD-56X. The target unit’s
MAC address can be found by entering an I and then an E from the Main
Menu shown in figure 2-1.
4. After entering the Feature and Unlock codes, return to the Feature Configuration menu, shown in figure 2-3, and enter V to toggle the Vipersat
Management menu item to Enabled. The unit will automatically reboot in
order to implement the change for this setting.
Initial Configuration
2-6 Vipersat CDD-56X Series User Guide
5. When the reboot is completed, return to the Feature Configuration menu
and configure the settings for Vipersat STDMA and Auto Switching
according to the table below.
6. Save the settings to flash by entering S at the command prompt.
7. Enter X at the command prompt to exit the Feature Configuration menu
and return to the Administration screen.
8. Ensure that the Working Mode is set to Router-Vipersat.
If it is not, enter C and change the setting by selecting 4, as shown in
figure 2-5. The unit will reboot automatically in order to implement the
change for this setting.
Figure 2-5
Working Mode dialog
Set the IP Address
1. From the Main Menu, enter I to access the Interface Configuration menu
screen, then enter E to access the Ethernet Interface screen.
Table 2-2
Vipersat Feature Configuration
Unit Role Vipersat STDMA Auto Switching
Hub Enabled Enabled (optional) Enabled
Hub Expansion Enabled Disabled Disabled
Remote Expansion Enabled Disabled Disabled
Chapter 2 - Quick Start Configuration 2-7
Initial Configuration
Figure 2-6
Ethernet Interface screen
2. Enter I at the command prompt, and enter the IP address for this unit.
3. Save the settings to flash by entering S at the command prompt.
Configure the Route Table
Routing in a Vipersat Network
CDD-56X Demodulator Routers operating in Vipersat mode do not use the
small or large network described in the CDD-564L Installation and Operation
Manual. There is no HDLC address in a Vipersat network; instead, the
CDD-56X role designation — Hub or Remote, Expansion unit or not — determines routing rules that prevent multicast loops. This simplifies the configuration of a Vipersat network.
Because satellite networks are often used as extensions for access to services
such as the Internet or the PSTN, they lend themselves quite readily to private
addressing. For example, to provide Internet access to the satellite network, only
the Hub requires a public IP address in order for the entire satellite network that
is controlled by the Hub to have access to the Internet backbone. Utilizing
Network Address Translation (NAT), the administrator can effectively address
the network using a minimum number of static route statements.
Example:
The IP address 172.16.0.0 is the private address network number for class B
networks. If there is a router at the Hub with a connection to the Internet, the
operator can define the local network as a class B. If the operator splits the Class
B in half and points the upper half toward the satellite there will be over 16000
Initial Configuration
2-8 Vipersat CDD-56X Series User Guide
usable addresses at the Hub as well as at the Remotes. For details on IP addressing, refer to Appendix A, "Network Addressing".
By putting the one route statement “Remotes 172.16.128.0/17 Wan to Sat” in
the TDM Hub modem, and by using the route statement “GW 0.0.0.0/0 Wan to
Sat” at each of the remote modems, the network will successfully route packets.
The remotes can then be sub-netted as class C networks or below. Additional
routers at the remotes can be added for unusually large sites, allowing an additional layer of NAT without requiring any more explicit routing within the
Vipersat Modem/Routers.
Refer to the CDD-564L Installation and Operation Manual for additional information on entering routes.
Creating the Routes
The following procedure outlines the basic route structure that the target
CDD-56X will require for its role in the network. One of the key routes that
must be created is a gateway address for routing the data traffic that is received
by the unit.
1. From the Main Menu shown in figure 2-1, select Route Table by entering
R at the command prompt.
2. From the Configuring the Route Table screen shown in figure 2-7, enter
1 at the command prompt to set the first route that will define the default
gateway.
Chapter 2 - Quick Start Configuration 2-9
Initial Configuration
Figure 2-7
Configuring the Route Table screen
In a Hub configuration, the default gateway will typically point to a router on
the same LAN as the CDD-56X Hub unit.
In a Remote configuration, the default route will typically point to the satellite
modem used for communications back to the Hub.
3. When prompted, enter the Route Name (GW), the IP Address, the
Number of Bits in the subnet mask, the Route Interface (Ethernet or Sat-
ellite), and the Next Hop address. The system administrator can supply
this information, if necessary.
In a Hub role, for example, enter the name of the route (e.g., GW), enter
0.0.0.0 for the destination IP address and 0 for the mask, enter E for
Ethernet interface, then enter the IP address of the appropriate router or
modem for the next hop.
4. Enter S at the command prompt in figure 2-7 to save the settings to flash.
Set the Satellite Demod Configuration
1. Enter M from the Main Menu, then enter C from the Satellite
Demodulator menu to access the Configuration screen.
Initial Configuration
2-10 Vipersat CDD-56X Series User Guide
2. Enter R to access the Rx Configuration screen shown in figure 2-8. Set
the Rx parameters for Frequency, Data Rate, FEC, Code Rate, and
Modulation as specified by the network administrator.
The Receive parameters must be set for each Demod. Enter Z at the command prompt to select the desired Demod, then set the Receive parameters
for that Demod. Repeat for each Demod.
Note: Only Turbo Product Coding is acceptable for FEC when the CDD-56X is
running in Vipersat mode.
Figure 2-8
Rx Configuration screen
3. Save the settings to flash by entering S at the command prompt.
Set the Vipersat Configuration
1. Enter V at the Main Menu command prompt (figure 2-1) to select the
Vipersat Configuration menu shown in figure 2-9.
NOTE
Chapter 2 - Quick Start Configuration 2-11
Initial Configuration
Figure 2-9
Vipersat Configuration screen (Hub)
2. Enter R at the command prompt to toggle the Unit Role to either Hub or
Remote.
This parameter will determine the role the target CDD-56X will perform in
the network and what type of commands and functions it will receive from
the VMS.
3. Enter E to set the Expansion Unit value to either Yes or No.
When configured as an Expansion unit, either as a Hub (switched) or as a
Remote (mesh), the CDD-56X is set up so that all Demods are in SCPC
mode and available as resources for dedicated communications with the
other end of the satellite link.
4. Enter B at the command prompt to set the Network ID.
The Network ID that is assigned to the unit defines to what network the
target CDD-56X will belong. All units used in a network will have the
same Network ID. This parameter is used by the VMS to identify units
common to a network and allows the VMS to manage multiple networks,
each with its own unique network ID number.
5. Enter N at the command prompt to set the Unit Name.
6. Enter V at the command prompt to set the Receive Multicast Address.
This IP address is the multicast address assigned to the VMS and to all
units in the network that are managed by the VMS. The Receive Multicast
Initial Configuration
2-12 Vipersat CDD-56X Series User Guide
Address of this CDD-56X must match the Transmit Multicast Address that
has been assigned to the VMS.
7. Enter I at the command prompt to set the Managing IP Address.
The Managing IP Address is the IP address of the VMS server.
8. Enter H to go to the Home State Configuration menu screen, then enter
W to set the current configuration as the Home State.
9. Save the settings to flash by entering S at the command prompt.
This completes the initial configuration of a CDD-56X from the factory default
settings to a functioning, Vipersat-enabled unit. Additional configuration
parameters must be set depending on the network requirements for a specific
application.
Refer to Chapter 3, “Using the Command Line Interface (CLI)”, for additional
details on configuring the target Vipersat CDD-56X.
Chapter 3 - Using the Command Line Interface (CLI) 3-1
C
HAPTER
USING THE COMMAND LINE
I
NTERFACE (CLI)
General
This chapter describes the use of the CLI for configuring and monitoring the
CDD-56X Demodulator/Router in a Vipersat network. Each CLI screen related
to a CDD-56X operating in Vipersat mode is presented, along with a detailed
description of the available commands. For descriptions of all other screens,
refer to the CDD-564L L-Band Quad Demodulator Installation and Operation
Manual.
Access to the CLI is provided through either the Console port (local, RS-232)
or the 10/100BaseT Ethernet Traffic port (Telnet, IP). Access via Telnet
requires login with password, Console access does not require login. The
screens presented in this document are as they appear when the CDD-56X is
accessed using Telnet.
When a Telnet terminal connection is made, the CDD-56X responds with a
Login prompt. The factory defaults are:
Login: comtech
Password: comtech
Once the operator has logged in, the Main Menu shown in figure 3-1 is
displayed.
General
3-2 Vipersat CDD-56X Series User Guide
Common Screen Commands
The following commands appear on each of the menu screens:
Demod Select
Some feature configurations apply to the CDD-56X as a unit, others are set on a
per Demod basis. This command (enter Z) allows the selection of one of the
two (CDD-562L) or four (CDD-564/564L) Demodulators.
Save Parameters to Permanent Storage
To Save the current parameter settings to permanent storage, enter S at the
command prompt. This command saves all data that has been entered from any
of the CLI screens since the last save was executed. Exiting a screen without
saving after parameters have been changed does not mean that the changes are
not applied. However, if these changes are not saved prior to a system reset or
power cycle, they will be lost.
Exit
To Exit the current menu screen and return to the previous screen in the menu
tree, enter X at the command prompt.
Telnet Logout
Enter L at the command prompt to Logout of the Telnet session. This command
appears only when connected via Telnet.
Chapter 3 - Using the Command Line Interface (CLI) 3-3
Menu Descriptions
Menu Descriptions
This section details the CLI menus and associated screens, and briefly discusses
the function of each of the commands available on each menu.
Main Menu
The Main Menu, shown in figure 3-1, allows configuring both the Demodulator and Router functions of the target CDD-56X.
Note: The menu item Vipersat Configuration shown in figure 3-1 will only be
displayed if the target CDD-56X has had the Vipersat option enabled as
described in the section “Setting Vipersat CDD-56X Operating Parameters” on page 2-3.
Figure 3-1
Main Menu screen
A Vipersat CDD-56X is normally shipped with the Vipersat option enabled.
The CDD-56X configuration can be determined by whether or not the command
line Vipersat Configuration is displayed on the menu, as shown in Figure 3-1.
Administration
The Administration menu provides access to the major Vipersat CDD-56X
features and commands. Entering an A at the prompt in the Main Menu, shown
in figure 3-1, displays the Administration screen shown in figure 3-2.
NOTE
Menu Descriptions
3-4 Vipersat CDD-56X Series User Guide
Figure 3-2
Administration screen
Enter an F at the prompt to display the Feature Configuration screen shown in
figure 3-3.
Feature Configuration
Figure 3-3
Feature Configuration screen
The Feature Configuration screen shown in figure 3-3 allows the Enabling
and Disabling of the major Vipersat CDD-56X features.
Chapter 3 - Using the Command Line Interface (CLI) 3-5
Menu Descriptions
Use this screen to enable and disable Vipersat features such as:
• Vipersat STDMA — Burst mode operation
• Vipersat Auto Switching — Allows switching to SCPC mode
• Vipersat File Streamer — Rapid file transfers over satellite network
Note: These Vipersat features must be Enabled or Disabled using this menu.
They are not accessible from the Vipersat Configuration menu.
Vipersat Feature Codes
From the Feature Configuration menu, verify whether or not the Vipersat
Feature Codes appear as shown in figure 3-3. These codes are entered prior to
shipment from CVNI; however, if the unit has been reset to factory default, the
codes will have to be re-entered. If the Feature codes are not displayed in the
menu, enter F at the command prompt.
The Vipersat Feature Codes can be entered as three hexidecimal digits at the
command prompt as shown in figure 3-4.
Figure 3-4
Feature and Unlock Code dialog
Each Feature code must have a corresponding Unlock code that determines
whether that feature has been purchased and is available for use on the target
CDD-56X.
Tip: Contact either the network administrator or Comtech Vipersat Networks
Customer Support to obtain the Feature and Unlock codes. A convenient
option is to use the Vipersat Vload utility to manage Feature and Unlock
codes.
NOTE
Menu Descriptions
3-6 Vipersat CDD-56X Series User Guide
Vipersat Management
This item is an information-only display, and indicates whether Vipersat
Management is Enabled or Disabled in the target CDD-56X. Activation of the
Vipersat Feature Code automatically enables the Vipersat Management feature.
Caution: This command must be Enabled in order to utilize any of the Vipersat
capabilities of the CDD-56X.
Vipersat STDMA
In order to utilize the Vipersat STDMA feature (burst mode) in the target
Vipersat CDD-56X, this feature must be Enabled. Enter A at the command
prompt to toggle On or Off.
Refer to table 2-2 for the relationship between Unit Role and STDMA. This
feature should only be enabled for a unit that is used as a Hub with no expansion
(i.e., a Burst Controller).
Note: Although the CDD-56X has multiple demods, STDMA is configurable for
only one demod. When this parameter is enabled, Demod 1 is set for
STDMA mode and the remaining demods are set for SCPC mode.
Vipersat Auto Switching
The Vipersat Auto Switching feature allows the CDD-56X to automatically
adjust to varying bandwidth demands in the Vipersat network by switching
between STDMA and SCPC connections. This feature should only be enabled
for a unit that is used as a Hub with no expansion, and that will be required to
send switching requests to the VMS in response to either traffic type (Application switching) or network traffic loads (Load switching). Refer to table 2-2 for
the relationship between Unit Role and Auto Switching.
To activate the Vipersat Auto Switching capabilities of the target CDD-56X,
toggle the Auto Switching command to Enabled by entering W at the command
prompt.
See the section “STDMA/SCPC Automatic Switching” on page 3-29 for more
details on the use of this feature. For additional information, refer to Appendix
B, “Automatic Switching”.
Vipersat File Streamer
Vipersat File Streamer (VFS) is an optional feature that allows rapid file transfers over the satellite network between host PCs that are running the client VFS
application. To activate the Vipersat File Streaming capabilities of the
NOTE
Chapter 3 - Using the Command Line Interface (CLI) 3-7
Menu Descriptions
CDD-56X, toggle this command to Enabled by entering R at the command
prompt.
Once the parameters on the Feature Configuration screen have been set as
desired, return to the Main Menu and enter the V command to display the
Vipersat Configuration screen shown in figure 3-5.
Vipersat Configuration
3-8 Vipersat CDD-56X Series User Guide
Vipersat Configuration
Entering V at the prompt from the CDD-56X Main Menu shown in figure 3-1
displays the Vipersat Configuration menu shown in figure 3-5.
Figure 3-5
Vipersat Configuration screen (Hub)
This menu lists the available commands for configuring a Vipersat CDD-56X.
Note that for the Hub unit only, the command Primary Heart Beat is displayed
in the Vipersat Configuration screen. For the Remote unit only, the status of the
Home State Revert setting is displayed.
Each of these commands is explained in the following sections.
STDMA Mode
The STDMA Mode parameters for this CDD-56X are accessed by entering T at
the Vipersat Configuration screen command prompt.
The items in the STDMA menu will vary depending on the function the target
CDD-56X performs in the network. The STDMA screen shown in figure 3-6 is
from a CDD-56X serving as a Hub with STDMA in the network.
For comparison, the STDMA screen for a CDD-56X operating in SCPC mode
(either as a Hub expansion unit or as a Remote mesh unit) is shown in
figure 3-7. Note that many of the options available for a CDD-56X operating
with STDMA are not available when configured for SCPC. This is because
Chapter 3 - Using the Command Line Interface (CLI) 3-9
Vipersat Configuration
STDMA is disabled for these two role configurations and the options displayed
on this screen do not apply.
Figure 3-6
STDMA screen (Hub, STDMA, Fixed type)
Figure 3-7
STDMA screen (Hub/Remote, SCPC)
Vipersat Configuration
3-10 Vipersat CDD-56X Series User Guide
STDMA
This menu item is read-only and shows the current state of STDMA in the
CDD-56X. In order to change the STDMA state, refer to the section “Feature
Configuration” on page 3-4.
STDMA Tx Rate
This menu item shows the STDMA Transmit Rate (in bps) of data that the
CDD-56X receives. This item is read-only and cannot be modified in this menu.
Hub Type
This menu item is only displayed if the CDD-56X is being used as a Hub in the
network, and provides the functionality for the STDMA Burst Controller.
Vipersat STDMA has five modes of operation:
• Fixed — all remotes get the same data slot time (slot size) in the cycle,
regardless of activity. Cycle time is fixed also.
• Dynamic Slot — data slot time of remotes vary according to activity,
cycle time does not.
• Dynamic Cycle — slot time and cycle time vary according to activity of
remotes.
• GIR (Guaranteed Information Rate) — each remote always has at least the
minimum data slot size when needed, and cycle time is variable up to a
maximum of one second.
• Entry Channel — remotes run in SCPC mode, but STDMA is used for
maintenance and control channel.
The Hub can be configured to operate as one of the five types by entering a T at
the command prompt to display the dialog shown in figure 3-8.
Figure 3-8
Hub Type prompt
Chapter 3 - Using the Command Line Interface (CLI) 3-11
Vipersat Configuration
This selection determines whether available bandwidth will be a static (fixed)
assignment, or whether bandwidth allocation will be dynamic with automatic
switching to dynamically optimize bandwidth utilization.
1 – Fixed
In the Fixed mode, all remotes have the same data slot size regardless of type of
traffic or load. This mode minimizes the amount of jitter between remote transmission times, and is useful for tuning STDMA as well as for troubleshooting
purposes.
2 – Dynamic Slot
In the Dynamic Slot mode, slot size is adjusted each cycle depending on the
activity during the previous cycle. The slot size for each remote is computed
based on the time (at the current data rate) needed to transmit all the bytes in
queue. If the result is less than the minimum slot size or more than the maximum slot size, the slot is adjusted accordingly. This mode allows the burst
controller to provide additional slot time in the cycle to remotes with higher
traffic demands, and helps to alleviate congestion.
3 – Dynamic Cycle
In the Dynamic Cycle mode, available bandwidth is allocated to remotes
proportionally based on their current bandwidth needs. The bandwidth requirements are determined by the number of bytes in queue for each remote divided
by the total number of bytes in queue for all remotes to determine the percentage of bandwidth to allocate for each remote. This mode provides improved
efficiency of STDMA due to faster cycle times during periods of light traffic
demands, thus providing minimum latency for the current load.
4 – GIR
In the GIR mode, the initial computed slot size value is the same as in the
Dynamic Cycle mode except there is no maximum limit. After all remotes have
been assigned slots, the burst map is checked to see if the total cycle length
exceeds one second. If not, then all requirements are satisfied and the burst map
is complete. However, if the cycle is greater than one second, then the slots are
adjusted proportionally so that all remotes receive at least their guaranteed rate
plus whatever excess is still available.
GIR mode allows guaranteed information rates to be set for each remote in the
group. When the one second restriction is exceeded, remotes without a specified
GIR are reduced to the global minimum slot size and the remaining bandwidth
is distributed to remotes that have been assigned a GIR rate, thus ensuring additional bandwidth to these units when needed.
Vipersat Configuration
3-12 Vipersat CDD-56X Series User Guide
Note: GIR allocations are restricted so that assigned GIR totals cannot exceed
the available bandwidth to insure proper bandwidth allocation when the
network is overloaded.
When combined with Auto switching, GIR allows trigger points to be set where
the Remote will jump out into SCPC mode.
5 – Entry Channel
The Entry Channel mode provides remotes in the group with a shared channel
in which they can gain initial access to the network. Since very small STDMA
data rates are required in this configuration, a larger number of remotes can
share the cycle. As soon as the Hub receives an STDMA ACK from the
Remote, it initiates an immediate switch to SCPC mode based on the policy set
for that Remote. Note that the switch occurs as soon as the Hub receives an
ACK even though there may not be traffic at that time. The persistence of the
link will be determined by the unit’s flag settings.
When choosing Entry Channel as the Hub type for the STDMA Controller, the
Auto switching feature must be Enabled on this Hub unit, and switching policies
for the remotes must be configured (refer to the section “Set Remote Policies”
on page 3-21). Corresponding Remote modems must be configured with Auto
switching and Load switching Enabled. Note that the settings for Step Up and
Step Down Threshold values should be adjusted as necessary for the application.
This mode is designed to accommodate the needs of a Remote that will not be
continuously connected to the network, but which has the need to be able to
make an on-demand connection when required, such as in a mobile application.
In the event of a power outage, Entry Channel provides a bandwidth-efficient
method for remotes with low latency requirements to re-enter the network once
power is restored.
Refer to Appendix B, “Automatic Switching”, for additional information on
how each of the bandwidth allocation modes functions and the parameters used
to calculate the commands for each mode.
Group ID
The STDMA Group ID number defines a group of equipment (including
CDD-56X Hub and Remote units) that will respond to the output of a single
STDMA burst controller. This group is addressable within a network which, in
turn, is defined by the Network ID number assigned to the CDD-56X.
Allocation of bandwidth is shared among the remotes in an STDMA group.
Depending on the number of remotes in a network, a Hub may have multiple
burst controllers, each with its own set of remotes. This is accomplished by
NOTE
Chapter 3 - Using the Command Line Interface (CLI) 3-13
Vipersat Configuration
assigning a unique Group ID number to each controller and its associated
remotes.
Note: The STDMA Group ID number and the Network ID number are indepen-
dent. There can be multiple STDMA groups within a single network.
The target CDD-56X Group ID can be modified by entering an I at the
command prompt to display the dialog shown in figure 3-9.
Figure 3-9
Group ID prompt
Low Data Rate Fast Acquisition
This menu item is a toggle used to Enable or Disable the Vipersat Burst Fast
Acquisition Timing (BFAT) feature that functions at low data rates (64 kbps to
256 kbps). This feature allows for significantly faster acquisition times at these
data rates, even with higher noise, resulting in improved efficiency of the shared
STDMA channel. Since signal lock is faster at higher data rates, BFAT is not
active above 256 kbps.
Entering A at the command prompt will toggle this feature On or Off.
This feature requires Router firmware version 1.5.3 or later. The configuration
must be set to operate at 3/4 QPSK in order to utilize BFAT.
Burstmap Multicast IP
This menu item is used to define the IP address for the Burstmap Multicast that
is sent out by the STDMA burst controller at the Hub to all of the associated
remotes in that group. This address must be the same for all members of the
goup. The burstmap is a proprietary message sent from the Hub to all remotes,
at regular intervals, specifying the relative start time and duration for each
terminal to transmit.
To change the current address, enter N at the command prompt to display the
dialog shown in figure 3-10.
NOTE
Vipersat Configuration
3-14 Vipersat CDD-56X Series User Guide
Figure 3-10
Burstmap Multicast IP prompt
Outbound IP
This menu item, which appears for all Hub configurations, displays the current
Outbound IP address. This specifies the Hub device that is supplying the TDM
outbound to the satellite (typically a CDM-570L). Specifying this address is
necessary for Hub configurations that utilize a burst controller (such as the
CDD-56X) that is a separate device from the TDM modem.
To change the target address of the TDM outbound for DPC messages for the
STDMA controller, enter O at the command prompt to display the dialog shown
in figure 3-11.
Figure 3-11
Outbound IP prompt
Cycles Per Burst Map
This menu item, which appears for all Hub types except Dynamic Cycle and
GIR, displays the number of spin cycles that will occur prior to each broadcast
of the Burst Map by the burst controller to the remotes. One cycle is the amount
of time it takes for all remotes in a group to burst on the common channel. The
burst map provides each remote with its allocated bandwidth and position in the
cycle.
For Dynamic Cycle and GIR configurations, the number of cycles is automatically set to one in order to ensure optimum performance for these Hub types.
This parameter can be modified by entering a C at the command prompt to
display the dialog shown in figure 3-12.
Chapter 3 - Using the Command Line Interface (CLI) 3-15
Vipersat Configuration
Figure 3-12
Cycles per Burst Map prompt
Slot Guardband
This menu item, which appears for all Hub configurations, displays the current
length of the Slot Guardband in milliseconds and in bytes for the remotes in the
group. The Slot Guardband is the amount of time between the point when one
remote completes transmitting data and the point when the next remote in the
cycle begins transmitting. This prevents the remote from overrunning the next
terminal in the cycle. A typical setting for this parameter is 15 milliseconds
(ms).
This value can be modified by entering a G at the command prompt to display
the dialog shown in figure 3-13 and entering a new value.
Figure 3-13
Slot Guardband prompt
Note: Note that the value entered at the command line in figure 3-13 is in milli-
seconds. The corresponding value expressed in bytes is calculated by
the CDD-56X based on the STDMA transmit bit rate as shown in the
menu in figure 3-6.
Slot Preamble Length
This menu item, which appears in all Hub configurations, displays the current
Slot Preamble size in milliseconds and bytes for the remotes in the group. The
Slot Preamble is the period between when the remote begins to transmit (sends
an ACK) to the Hub and when the first data packet is sent. This allows time for
signal lock to occur before data is sent, thus preventing data loss. Higher data
NOTE
Vipersat Configuration
3-16 Vipersat CDD-56X Series User Guide
rates allow for a shorter preamble, since it is easier to achieve signal lock. An 80
millisecond (ms) preamble is typical for a data rate of 512 kbps.
Entering a P at the command prompt allows changing the preamble duration in
milliseconds.
Figure 3-14
Slot Preamble Length prompt
Tip: Refer to the Viper Calculator for determining Slot Preamble Length values
to enter at the command prompt. For a copy of the latest Viper Calculator,
contact a Comtech Vipersat Networks representative.
Slot Data Length
This menu item, which appears for Fixed and Entry Channel Hub types,
displays the current Slot Data Length in milliseconds and bytes for the remotes
in the group, and represents the amount of data that can be transmitted or
received in one spin of the STDMA cycle by each of the remotes belonging to
that group. This is the amount of time that the remote is provided to send data in
the cycle.
To change this setting, enter B at the command prompt to display the dialog
shown in figure 3-15.
Figure 3-15
Slot Data Length prompt
Chapter 3 - Using the Command Line Interface (CLI) 3-17
Vipersat Configuration
Nominal Data Length
This menu item, which appears for Dynamic Slot Hub type, displays the Nominal slot Data Length in milliseconds and bytes for the remotes in the group,
and represents the approximate amount of data that can be transmitted or
received in one spin of the STDMA cycle by each of the remotes belonging to
that group. This is the amount of time that the remote is provided to send data in
the cycle.
Entering a B at the command prompt brings up the dialog shown in figure 3-16
allowing changing the nominal data length, in milliseconds, for the target
CDD-56X.
Figure 3-16
Nominal Data Length prompt
Maximum Data Length
This menu item, which appears for Dynamic Cycle Hub type, displays the
current Maximum Data Length in milliseconds and bytes for the remotes in
the group, and represents the maximum amount of data that can be transmitted
or received in one spin of the STDMA cycle by each of the remotes belonging
to that group. This is the maximum amount of time that the remote is provided
to send data in the cycle.
To change this setting, enter B at the command prompt to display the dialog
shown in figure 3-17.
Vipersat Configuration
3-18 Vipersat CDD-56X Series User Guide
Figure 3-17
Maximum Data Length prompt
Minimum Data Length
This menu item, which appears for all Hub types except Fixed, displays the
current Minimum Data Length in milliseconds and bytes for the remotes in the
group, and represents the minimum amount of data that can be transmitted or
received in one spin of the STDMA cycle by each of the remotes belonging to
that group. This is the minimum amount of time that the remote is provided to
send data in the cycle.
Entering an M at the command prompt brings up the dialog shown in
figure 3-18 allowing the minimum data length, in milliseconds, to be changed
for the target CDD-56X.
Figure 3-18
Minimum Data Length prompt
Slot Cycle Length
This menu item is for information only and displays the Slot Cycle Length in
milliseconds and bytes for the remotes in the group. This value represents the
total amount of time—preamble, data length, and guardband—allocated to the
Remote terminal during one spin cycle.
Chapter 3 - Using the Command Line Interface (CLI) 3-19
Vipersat Configuration
Slot Start in Cycle
This menu item appears in the STDMA screen when the Unit Role is Remote;
however, it is not relevant since a Remote configuration does not enable
STDMA.
Set Remotes
This menu item appears in the STDMA screen when the Unit Role is Hub with
No Expansion.
Entering an R at the command prompt displays the STDMA Remotes Menu as
shown in figure 3-19. This screen is used to define and make modifications to
the Remotes that belong to the STDMA group for the Hub burst controller, as
well as to display the burst map status information for each Remote.
Figure 3-19
STDMA Remotes Menu screen
Adding a Remote to the STDMA Group
Entering the item number for the Remote demodulator/router brings up the
dialog shown in figure 3-20. A prompt to enter the Name to assign to the
Remote unit appears, followed by a prompt to enter the IP Address for this unit.
Vipersat Configuration
3-20 Vipersat CDD-56X Series User Guide
Figure 3-20
Remote Name and IP Address prompt
Once a Remote has been added to the group, its Status in the group is displayed
by the use of the following letters:
• U = Used – This Remote is being used in the burstmap.
Once a remote has been added to the STDMA group, this status will
always be displayed.
• B = Burstmap – This Remote is currently in the burstmap.
This status will be displayed unless the remote has been removed (R),
disabled (D), or switched (S) out of the STDMA burstmap.
• R = Removed – This Remote is currently removed from the burstmap.
When displayed, this status indicates that the Hub has removed this remote
from the burstmap due to a communications fault.
• D = Disabled – This Remote is currently disabled and is not in the
burstmap.
This status will be displayed when a remote is manually disabled by the
operator or administrator.
• S = Switched – This Remote is currently switched into SCPC mode.
When displayed, this status indicates that the VMS has automatically
switched the remote out of the burstmap and into SCPC operation.
Base
Entering a B at the command prompt in figure 3-19 allows entering the Remote
number to start displaying remotes in this menu screen. Entering the number 1,
as shown in figure 3-19, displays nine remotes, 1 through 9. If the number 4 had
been entered, the display would show the nine remotes starting with Remote 4
(i.e., remotes 4 through 12).
Chapter 3 - Using the Command Line Interface (CLI) 3-21
Vipersat Configuration
Figure 3-21
Base Remote Display prompt
Remote Count
The Remote Count menu item in figure 3-19 is an information-only display
showing the total number of Remotes that currently belong to the STDMA
group for this Hub burst controller.
Set Remote Policies
This menu item, which appears for GIR and Entry Channel Hub types, allows
each Remote to be configured for specific data switching conditions. Entering P
at the STDMA Remotes Menu command prompt displays the Remote Policies
screens shown in figure 3-22 (GIR Hub) and figure 3-24 (Entry Channel Hub).
Figure 3-22
STDMA Remote Policies screen (GIR Hub)
Entering the Remote number at the command prompt in figure 3-22 allows the
Guaranteed Information Rate and the Automatic Load Switch Rate for that
Remote to be set, as shown in figure 3-23. Note that the Available Bandwidth is
displayed for reference in this screen to assist with entering the appropriate
rates. The cycle length for GIR is limited to a maximum of one second.
Vipersat Configuration
3-22 Vipersat CDD-56X Series User Guide
Figure 3-23
GIR Remote Policies prompt
Set the Automatic Load Switch Rate to a value greater than the GIR to allow the
Remote to be automatically switched out of STDMA and into SCPC mode
when traffic exceeds the GIR. A Switch Rate of 0 will prevent the Remote from
being switched out of STDMA and into SCPC mode.
The Remote Policies screen for an Entry Channel Hub type allows the SCPC
data rates and switch types to be specified for when the Remotes will switch and
the desired starting points for communications.
Figure 3-24
Entry Channel Switch Rates screen
Entering the Remote number at the command prompt in figure 3-24 allows the
SCPC Data Rate and the Switch Type for that Remote to be set, as shown in
figure 3-25. Switch type 0 corresponds to Load Switching; switch types 64
through 255 are user-defined, and must match VMS policies. When choosing
Load Switching as the Switch Type, the associated Remote must have the Load
Chapter 3 - Using the Command Line Interface (CLI) 3-23
Vipersat Configuration
Switching feature Enabled (see the section “STDMA/SCPC Automatic Switching” on page 3-29).
Figure 3-25
Remote SCPC Data Rate prompt
The Global SCPC Rate command can be used to set the data rate for all or a
majority of the Remotes. This allows the rate to be entered just once instead of
entering the rate for each Remote individually. Enter G at the command prompt
in figure 3-24.
Figure 3-26
Global SCPC Data Rate prompt
Similarly, the Global Switch Type command can be used to set the switch type
for all or a majority of the Remotes. Enter H at the command prompt.
Figure 3-27
Global Switch Type prompt
Delete Remote
Entering D at the command prompt shown in figure 3-19 brings up the Delete
Remote dialog shown in figure 3-28.
Vipersat Configuration
3-24 Vipersat CDD-56X Series User Guide
Figure 3-28
Delete Remote prompt
Enter the number of the Remote CDD-56X at the command prompt to delete it
from the STDMA group for this Hub burst controller.
Enable/Disable Remote
Enter E at the command prompt in figure 3-19 to display the dialog shown in
figure 3-29. The Remotes in the network are displayed, indicating whether each
is currently Enabled (E) or Disabled.
Figure 3-29
Enable/Disable Remote prompt
Enter the number of the Remote at the command prompt to toggle the Remote
from its current Enable/Disable configuration.
In the example screen shown above, both Remotes 1 and 2 are Enabled.
View Remote(s)
Entering V at the command prompt shown in figure 3-19 will display the listing
of Remote(s) that belong to the STDMA group for this Hub burst controller, and
their status, as shown in figure 3-30.
Figure 3-30
View Remote(s) screen
Chapter 3 - Using the Command Line Interface (CLI) 3-25
Vipersat Configuration
The display is for information only and pressing any key will return the screen
to the menu shown in figure 3-19.
Remove Timeout
Entering R at the command prompt shown in figure 3-19 will display the
Remove Timeout dialog shown in figure 3-31. Note that this menu item shows
the current setting (in seconds) for this parameter.
Figure 3-31
Remove Timeout prompt
The value entered at the command prompt defines the amount of time (in
seconds) with no communication from a Remote to the Hub before that Remote
is removed from the Burst Map. If communications are lost for this specified
period of time, the Remote is removed from the STDMA group, and the bandwidth resources it had been allocated are then made available for use by the
other remotes remaining in the group.
This feature is useful, for example, in an SNG application where a mobile
Remote has finished its assignment and has shut down.
Remove Retry Timeout
Entering T at the command prompt in figure 3-19 will display the Remove
Retry Timeout dialog shown in figure 3-32. Note that this menu item shows
the current setting (in seconds) for this parameter.
Figure 3-32
Remove Retry Timeout prompt
Vipersat Configuration
3-26 Vipersat CDD-56X Series User Guide
When a Remote is removed from the group Burst Map, as described in the
section “Remove Timeout” above, entering a value in the Remove Retry Timeout dialog defines the amount of time (in seconds) that is allowed to pass before
a retry attempt is made to return the removed Remote to the group. The Remote
is re-entered into the burst map cycle; if the Remote does not burst back (ACK)
to the Hub burst controller, it is again removed from the Burst Map.
This allows, again using a mobile Remote as an example, shutting down the
Remote at one location, moving it to a new location, and then automatically reestablishing a connection to the satellite network.
STDMA Statistics
Entering V at the command prompt in the STDMA screen displays the STDMA
Statistics screen as shown in either figure 3-33 (Hub) or figure 3-34 (Remote).
Note that statistics will only be accumulated for a CDD-56X that is configured
as a Hub with No Expansion, since that is the only configuration that provides
STDMA functionality (on Demod 1). Because a Remote unit is SCPC mode
only, the STDMA Statistics screen will display all values as 0.
Figure 3-33
STDMA Statistics screen (Hub)
Chapter 3 - Using the Command Line Interface (CLI) 3-27
Vipersat Configuration
Figure 3-34
STDMA Statistics screen (Remote)
Stats Accumulation Window
Entering W at the command prompt displays the Stats Accumulation Window
as shown in figure 3-35. The time period, in seconds, for capturing STDMA
statistics can be specified.
Figure 3-35
Stats Accumulation Window prompt
Clear
The STDMA statistics can be Cleared (reset) by entering a C at the command
prompt in figure 3-33.
Show Hub Statistics
Entering a W at the command prompt in the STDMA screen displays the
current statistics for the target CDD-56X Hub as shown in figure 3-36.
Vipersat Configuration
3-28 Vipersat CDD-56X Series User Guide
Figure 3-36
Show Hub Statistics screen
The Burst Controller monitors statistics in the received ACK from each Remote.
The statistics report the fill status of the STDMA buffers. The Burst Controller
builds a table of the group and calculates the relative buffer fill for each Remote.
It then calculates the length of the Data Slot for each Remote based on the Minimum Slot Size plus a percentage of the Available Bandwidth. Idle remotes
would receive a Data Slot equal to the Minimum Slot Size.
In figure 3-36, Remote 1 with IP address 10.1.128.1 had activity during the
averaging period. It captured 37.8% of the total slot time and had an average
slot length of 283 ms. Remotes 2, 3, and 4 had 41.5%, 18.1% and 7.6% respectively. The dynamic range of STDMA is a function of the difference between
the nominal Data Slot Size and the Minimum Data Slot Size parameters. These
parameters are operator selectable. The speed with which STDMA reacts to
changes in dynamic load is a function of the Statistics Accumulation Window
parameter and the Cycles per New Burst Map parameter, both of which are also
operator selectable.
The Hub statistics are useful for tuning the Burst Controller. Preamble adjustments, up or down, are made using the missed ACKs statistic; a preamble and/
or guardband that is too short will result in an accumulation of missed ACKs.
The “Cont” column represents continuous—the number of sequential ACKs
missed.
An informative indicator in the Hub Statistics screen is the STDMA status of
the Remotes that appears in the first column to the right of the IP Address list.
The Remote status is displayed in one of three possible modes:
• E – Remote is Enabled and active in the STDMA group; the Hub burst
controller is receiving ACKs from this Remote.
• ER – Remote is Enabled but has been Removed from the STDMA group
due to missed ACKs at the Hub burst controller.
• (Blank) – Remote either has been manually Disabled, such as through the
STDMA Remotes Menu Enable/Disable command, or has been switched
out of STDMA to SCPC mode by the VMS.
Chapter 3 - Using the Command Line Interface (CLI) 3-29
Vipersat Configuration
STDMA/SCPC Automatic Switching
One of the most powerful features of the Vipersat Network system is the capability to perform Automatic switching between STDMA mode and SCPC mode
based on bandwidth demand. The configuration options that are available to
meet customer-specific requirements are extensive, and include switching based
on Load, Application (Voice and Video RTP), ToS, and QoS.
For additional information, refer to Appendix B, “Automatic Switching”, in this
document.
Note: Care must be taken when configuring the Auto Switching features of the
Vipersat system to ensure that there is no duplication or overlap of
switching functions between Application, ToS, and QoS for a particular
traffic flow. Only one of these switching methods should be utilized for
any one flow requirement.
Automatic Switching for the CDD-56X is an option that is available only when
configured as an STDMA Hub unit (burst controller). Note that Automatic
switching does not apply to either a Hub with Expansion or a Remote with
Expansion; these configurations operate in dedicated SCPC mode and all
switching control is performed by the VMS. As is shown in table 2-2, Auto
Switching should be Disabled for these two configurations.
The Auto Switching feature must be Enabled (as described in the section
“Feature Configuration” on page 3-4) in order to allow any associated Remote
modems to perform STDMA/SCPC switching. In order for a Remote modem in
the group to be automatically switched between STDMA and SCPC modes, the
Auto Switching feature of that Remote must be Enabled as well.
Auto Switching a Hub CDD-56X
Selecting Automatic Switching from the Vipersat Configuration menu
shown in figure 3-5 (enter A) for a CDD-56X operating as a network Hub will
display the menu shown in figure 3-37.
NOTE
Vipersat Configuration
3-30 Vipersat CDD-56X Series User Guide
Figure 3-37
Automatic Switching screen
The following sections describe the menu items of the STDMA/SCPC Auto
Switching screen shown in figure 3-37.
Auto Switching
The Auto Switching item on the menu shown in figure 3-37 is for information
only and shows the current configuration of the Hub CDD-56X. This feature is
Enabled and Disabled as described in the section “Feature Configuration” on
page 3-4. Auto Switching must be Enabled in order to utilize any of the related
features/commands in this menu.
Note that Auto Switching must be Enabled on a Hub STDMA Controller that is
configured for Entry Channel mode.
Current WAN Transmit Mode
The Current WAN Transmit Mode item on the menu in figure 3-37 is information only and reflects the current transmit status of a unit. In the case of the
CDD-56X, there is no transmit function (no modulator) and this parameter is
not applicable.
Load Switching
The Load Switching command on the menu in figure 3-37 is a toggle Enabling
and Disabling Load Switching on the target Hub CDD-56X. The system will
detect variations in data rate and can be configured to switch from STDMA to
SCPC based on bandwidth requirements.
The initial switch for a Remote Vipersat terminal from STDMA mode to SCPC
mode is determined by the Hub Burst Controller. Once the Remote is switched
Chapter 3 - Using the Command Line Interface (CLI) 3-31
Vipersat Configuration
into SCPC, any requests to meet additional switching requirements within
SCPC (Step Up or Step Down) are made by the Remote modem.
Entering a B at the command prompt will toggle this feature On or Off for the
target CDD-56X.
Note: Load switching must be Enabled for any Hub CDD-56X burst controller
that will experience changing load conditions in order for the VMS to
dynamically optimize network performance on these circuits.
Application switching by the VMS (Voice and/or Video) is not affected by
this setting. However, using Load switching for real-time applications is
not recommended.
STDMA Slot Capacity
The STDMA Slot Capacity command, shown in figure 3-37, allows setting the
threshold or level of slot capacity at which the Burst Controller sends a switch
request to the VMS to switch the Remote from STDMA mode to SCPC mode.
Enter U at the command prompt to display the dialog shown in figure 3-38.
Figure 3-38
STDMA Slot Capacity prompt
Typically the default settings will be optimum, but there may be unique network
configurations which require modifying the STDMA Slot Capacity value.
STDMA Switch Delay
In order to minimize unnecessary switching from STDMA to SCPC due to transient conditions, such as a temporary spike in network traffic for example, a
switch delay parameter is provided. This setting is used to specify a delay before
a switch occurs.
Typically the default values will be optimum, but this value can be changed to
accommodate a unique network configuration or application. To change this
setting, enter W at the command prompt in figure 3-37 to display the screen
shown in figure 3-39.
NOTE
Vipersat Configuration
3-32 Vipersat CDD-56X Series User Guide
Figure 3-39
STDMA Switch Delay prompt
Percent Allocation
The Percent Allocation menu item, shown in figure 3-37, allows adding a fixed
percentage to the channel bandwidth request to accommodate additional bandwidth requirements which may occur after a switch is made from STDMA to
SCPC mode.
To change this setting, enter E at the command prompt to display the screen
shown in figure 3-40.
Figure 3-40
Percent Allocation prompt
Typically the default value will be optimum, but if there may be a larger bandwidth requirement after the switch, the percent allocation value can be
increased. In choosing a value for this allocation, future bandwidth requirements for the channel must be balanced against efficient bandwidth utilization.
Time for Carrier Inhibit
The Time for Carrier Inhibit feature only applies to Remote transmitting
equipment. Because the CDD-56X has no transmitter, this feature does not
apply.
Chapter 3 - Using the Command Line Interface (CLI) 3-33
Vipersat Configuration
Unit Role
The Unit Role configuration determines whether the target CDD-56X is to
function as a Remote or as a Hub in the Vipersat satellite network. From the
Vipersat Configuration screen (figure 3-5), enter R to display the dialog
shown in figure 3-41.
Figure 3-41
Unit Role prompt
The information entered in this menu will determine the role the target
CDD-56X will perform in the network and what type of commands and functions it will receive from the VMS. See table 2-1 and table 2-2 for a breakdown
of network roles and related functions and features.
Expansion Unit
The Expansion Unit menu item in the Vipersat Configuration screen
(figure 3-5) defines whether the target CDD-56X is to function as an Expansion
unit (all demods configured to operate in SCPC mode) or not. Entering E at the
command prompt will display the dialog shown in figure 3-42.
Figure 3-42
Expansion Unit prompt
The VMS uses this data when monitoring and controlling the network to determine the target CDD-56X’s function. For example, in a Hub configuration that
has STDMA enabled for the first demod, Expansion Unit should be set to No.
Vipersat Configuration
3-34 Vipersat CDD-56X Series User Guide
When configured as an Expansion unit, either as a Hub (switched) or as a
Remote (mesh), the CDD-56X is set up so that all demods are in SCPC mode
and available as resources for dedicated communications with the other end of
the satellite link.
For a Remote configuration, this parameter must be set to Yes. For a Hub
configuration, this parameter can be set to either No or Yes. Refer to table 2-1
and table 2-2 for a breakdown of network roles and related functions and
features.
Network ID
The Network ID that is assigned to the unit defines to what network the target
CDD-56X will belong. All units used in a network will have the same Network
ID. Enter B at the command prompt in the Vipersat Configuration screen
(figure 3-5) to display the dialog shown in figure 3-43.
Figure 3-43
Network ID prompt
The Network ID is used by the VMS to identify units that are common to a
network and allows the VMS to manage multiple networks, each with its own
unique Network ID number.
Unit Name
The Unit Name command in the Vipersat Configuration screen (figure 3-5) is
used to assign a name to the target CDD-56X. Enter N at the command prompt
to display the dialog shown in figure 3-44 . Any name, up to 16 characters, can
be entered for the unit.
Chapter 3 - Using the Command Line Interface (CLI) 3-35
Vipersat Configuration
Figure 3-44
Unit Name prompt
This name is displayed by the VMS and identifies the unit in Network Manager,
the graphical network display.
Receive Multicast Address
The Receive Multicast Address is the multitcast IP address assigned to all
CDD-56X units in the Vipersat network that are managed by the VMS server.
This address must match the VMS Transmit Multicast Address.
When the CDD-56X receives a multicast from the VMS server, it receives
maintenance and control packets, including the server’s IP address. The
CDD-56X responds to the VMS server with a unicast containing its current
configuration data, including the CDD-56X’s IP address. When the VMS
receives the unicast response, it registers the CDD-56X on the network.
Enter V at the command prompt in the Vipersat Configuration screen
(figure 3-5) to display the dialog shown in figure 3-45.
Figure 3-45
Receive Multicast IP Address prompt
Switch requests can be unicast to the VMS server and unicast switch commands
received from the VMS by the CDD-56X. For more information on this process,
refer to the VMS User Guide.
Vipersat Configuration
3-36 Vipersat CDD-56X Series User Guide
Managing IP Address
The Managing IP Address command in the Vipersat Configuration screen
(figure 3-5) allows the IP address for the server running VMS to be entered.
Enter I at the command prompt to display the dialog shown in figure 3-46.
Figure 3-46
Managing IP Address prompt
The Managing IP Address of the VMS is sent out with the multicast to all of the
Vipersat units and will be automatically updated during the registration process.
If available, this is the IP address to which the CDD-56X sends a unicast registration request every 60 seconds when requesting initial registration on the
VMS network. Later the CDD-56X uses this address to send switch requests,
network health messages, etc. to the managing VMS server.
Primary Heart Beat
This menu item appears for the Hub terminal only.
The Primary Heart Beat feature is a redundancy heart beat message for
primary Hub units that provides the option for a periodic communications check
message to be sent from the Hub modem to the VMS for backup recovery in
N:M redundancy (protected) configurations. The message interval can be specified by the administrator through the VMS.
Enter P at the command prompt in the Vipersat Configuration screen
(figure 3-5) to toggle this feature between Enabled and Disabled.
Home State Revert
This menu item appears for the Remote terminal only.
The Home State Revert feature allows automatic resource recovery to be
performed on SCPC connections when a communications failure occurs
between the VMS and a Remote, such as a rain fade condition, a Remote unit
power down, or a hardware failure. The period of time (in minutes) for a failure
Chapter 3 - Using the Command Line Interface (CLI) 3-37
Vipersat Configuration
is configured in the VMS for each Remote in the network. Should communications be lost for more than the specified time period, the Remote will automatically revert to its Home State settings and the VMS will remove all allocated
resources (bandwidth, demod(s)), freeing them for use by any other Remote in
the Vipersat network.
Because this feature is configured in the VMS, the status (Enabled or Disabled)
appears as an information-only display in the Vipersat Configuration menu
(figure 3-5).
Dynamic Power Control Configuration
Dynamic Power Control (DPC) is a Vipersat feature that acts to regulate the
transmit power of the Vipersat satellite modem, such that the specified receive
signal level (Eb/No) is met for the receiving Vipersat units in the group. DPC is
driven by the receiver demod, which notifies the transmitting modem of the
current Eb/No value.
Refer to Appendix C, “Dynamic Power Control”, in this document for additional information on the DPC feature.
The Dynamic Power Control Configuration screen (enter C in the Vipersat
Configuration menu) allows for setting the parameters for the CDD-56X power
levels. The information and commands in the menu will vary depending on the
function the target CDD-56X performs in the network. The screen shown in
figure 3-47 is from a unit serving as a Hub with STDMA (burst controller).
Note, however, that the only parameter settings that apply to the CDD-56X are
DPC Enabled, Speed Up EbNo, and Target DPC Address. Because all of the
remaining settings shown in this screen are redundant to those configured in the
satellite modem, they do not apply to the CDD-56X and can be disregarded.
For comparison, the DPC Configuration screen for a unit operating as a Hub or
Remote with Expansion (SCPC mode) is shown in figure 3-48. Note that only
the applicable settings appear in this screen.
Vipersat Configuration
3-38 Vipersat CDD-56X Series User Guide
Figure 3-47
DPC Configuration screen (Hub, STDMA)
Figure 3-48
DPC Configuration screen (Hub/Remote, SCPC)
DPC Enabled
The DPC Enabled command (enter E) is a toggle that allows the Dynamic
Power Control feature to be either Enabled or Disabled. The CDD-56X is
shipped with the DPC Enabled menu item turned off (Disabled) to allow
entrance link levels calibration during terminal setup.
Chapter 3 - Using the Command Line Interface (CLI) 3-39
Vipersat Configuration
Speed Up EbNo
Normally, the PLDM (Path Loss Data Message) is sent every 60 seconds from
each terminal in the network. If the current Eb/No value of the terminal drops
below the Speed Up EbNo set value, the corresponding terminal increases its
PLDM send rate to every 15 seconds until the current value becomes greater
than the set value. This provides a loop speed up to rapidly regain link quality.
Enter Q at the command prompt in the DPC Configuration screen to access the
Speed Up EbNo dialog shown in figure 3-49. The default value for this parameter is 5 dB.
Figure 3-49
Speed Up EbNo prompt
Target DPC Address
The Target DPC Address identifies the modem that is transmitting to this
CDD-56X Demod, and will be receiving the PLDM messages that provide the
current Eb/No value for this Demod. Typically, all Remotes will specify the
Hub modem that is supplying the TDM outbound carrier.
For STDMA Remotes, the Outbound IP address is sent out via the Burst Map,
and the DPC Target for these Remotes is automatically mapped to that address.
However, since all CDD-56X Remotes operate as SCPC mesh units, the Target
DPC Address must be manually configured with this command.
Enter the number corresponding to the appropriate Demod (1, 2, 3, or 4) at the
command prompt to display the Target DPC Address dialog shown in
figure 3-50.
Vipersat Configuration
3-40 Vipersat CDD-56X Series User Guide
Figure 3-50
Target DPC Address prompt
The STDMA Burst Controller (Demod 1 on a CDD-56X configured as Hub
with No Expansion) is not permitted to specify a DPC Target because the
demodulator is receiving multiple bursts very rapidly from all Remotes in the
group and is unable to utilize DPC to control the transmit power of the Remote
modems.
Set Home State Parameters
A CDD-56X’s Home State consists of those parameters which provide a
known RF configuration that the CDD-56X will return to, either as the result of
a command by the VMS, or as it comes back on line from a reset or a power
cycle.
Enter H at the command prompt in the Vipersat Configuration screen to
display the Home State Configuration screen shown in figure 3-51.
Figure 3-51
Home State Configuration screen
Chapter 3 - Using the Command Line Interface (CLI) 3-41
Vipersat Configuration
A CDD-56X’s Home State settings are typically selected so that it goes to a
configuration which is optimum for its function in the network. These parameters are configured on an individual, per demod basis.
Note that each of these Receive parameters are the same as found in the Rx
Configuration screen that is in the Satellite Demod Configuration menu.
Set Current Configuration as Home State
This command sets the selected Demod’s current configuration as its Home
State settings. Assuming the Demod has been properly configured using the
Satellite Demodulator Configuration menu (Rx parameters) and the Feature
Configuration menu (Vipersat STDMA setting), these parameter values will be
copied into the Home State configuration. Rather than entering each of these
values individually, this command can be used as a shortcut for establishing the
Home State settings.
Enter W at the command prompt in the Home State Configuration screen to
execute this command. Once saved, the modem will be configured with the
Home State settings at boot time and when manually reset with the Force
Modem to Home State command.
Tip: This command is useful when a CDD-56X’s initial set up is completed and
the unit is functioning as desired in a network.
Force Modem to Home State
If at any time it is desired to have a CDD-56X return to its Home State, this
command (enter Y) can be executed. A warning message is displayed as shown
in figure 3-52, requiring the command to be confirmed before it is executed.
Figure 3-52
Force Modem to Home State warning
This command will force the selected Demod to its Home State configuration,
replacing its current configuration.
STDMA State
This command (enter T) toggles the setting of STDMA in the target
CDD-56X’s Home State between Enabled and Disabled. This is the same
Vipersat Configuration
3-42 Vipersat CDD-56X Series User Guide
feature that is set from the Feature Configuration menu screen shown in
figure 3-3. Setting the STDMA State to Enabled is only applicable for a
CDD-56X that is configured as a Hub burst controller.
Note: Only one demod can be set with STDMA enabled. Vipersat recommends
that Demod 1 be utilized for applications calling for STDMA.
Receive Frequency
Enter M to use the dialog shown in figure 3-53 to set the Receive Frequency
for the selected Demod’s Home State.
Figure 3-53
Receive Frequency prompt
Note that this screen dialog example displays the frequency range for a CDD562L/564L L-Band Demodulator/Router. For a CDD-564, the range displayed
will be either 50 to 90 MHz or 100 to 180 MHz.
Receive Data Rate
Enter N to use the dialog shown in figure 3-54 to set the Receive Data Rate for
the selected Demod’s Home State.
Figure 3-54
Receive Data Rate prompt
Note that the valid range for this parameter will vary depending on the Demodulation Type, Coding Rate, and FAST feature Data Rate.
NOTE
Chapter 3 - Using the Command Line Interface (CLI) 3-43
Vipersat Configuration
Receive FEC Type
Enter O to use the dialog shown in figure 3-55 to set the Receive FEC Type for
the selected Demod’s Home State. Turbo must be selected when operating in
Vipersat mode.
Figure 3-55
Receive FEC Type prompt
Receive Coding Rate
Enter P to use the dialog shown in figure 3-56 to set the Receive Coding Rate
for the selected Demod’s Home State.
Figure 3-56
Receive Coding Rate prompt
Note that Coding Rate 4 (1/1) is not a valid selection when operating in Vipersat
mode with Turbo Product Coding.
Receive Modulation Type
Enter Q to use the dialog shown in figure 3-57 to set the Receive Modulation
Type for the selected Demod’s Home State.
Vipersat Configuration
3-44 Vipersat CDD-56X Series User Guide
Figure 3-57
Receive Modulation Type prompt
Vipersat Summary
The Vipersat Summary screen can be viewed by entering D at the command
prompt in the Vipersat Configuration screen (figure 3-5).
Figure 3-58
Vipersat Summary screen
The Node ID number that appears in this screen verifies that the unit is registered with the VMS and is active in the network. This number is automatically
assigned by the VMS.
Note that the four Demods of the CDD-56X are designated as 0 through 3 on
this screen. The IF values represent the Intermediate Frequency (Hz) that this
unit is currently using. The AF values represent Adjusted Frequency (Hz), a
translation of the IF that is used by the VMS for internal tracking of switching
commands.
The DPC target entries are the IP addresses of the modulators that are to
receive the Dynamic Power Control messages from the Demods for this unit.
The Primary Heart Beat Interval represents the time period between the
communication check message that is sent from the primary Hub CDD-56X to
Chapter 3 - Using the Command Line Interface (CLI) 3-45
Vipersat Configuration
the VMS in an N:M redundancy configuration. This interval is specified in the
VMS.
Vipersat Migration
The Vipersat Migration command is used to set the compatibility mode for the
Hub Burst Controller when conducting a firmware upgrade on the associated
Remotes. Although this command appears in the menu for both the Hub modem
and the Remote modem, it only applies to STDMA Controllers and TDM
Outbound modems at the Hub.
Enter M at the command prompt in the Vipersat Configuration screen to
display the Vipersat Migration dialog shown in figure 3-59.
Figure 3-59
Vipersat Migration prompt
Refer to Appendix D, “Network Migration”, in this document for additional
information on the use of this command.
Vipersat Configuration
3-46 Vipersat CDD-56X Series User Guide
{ This Page is Intentionally Blank }
Appendix A - Network Addressing A-1
A
PPENDIX
NETWORK ADDRESSING
Introduction
This Appendix is an overview of network addressing and how it applies to
configuring the CDD-562L/564/564L for use in Vipersat Networks. The
subjects covered are:
• OSI Model
• Binary Math
• IP Addressing
• Network Address Translation
• Subnets
• Network Segments
• Default Gateways
• MAC Addresses
The OSI Reference Model
A-2 Vipersat CDD-56X Series User Guide
The OSI Reference Model
OSI is an acronym for Open Systems Interconnection. This is a network model
created by ISO (the International Standardization Organization.) The OSI model
is the basic standard which forms the basis for all networking protocols.
Figure A-1
The Seven OSI Protocol Layers
The OSI model defines the building blocks used to construct a working network
protocol as shown in Figure A-1. The blocks on the right show the individual
layers which make up the OSI model and the blocks on the left show the layer’s
functional grouping.
Each layer, as defined by the OSI model, is only aware of the layers directly
above and below it.
Layers 1 – 3
Layer 1 / Physical – Layer 1 defines the physical means by which actual bits
are sent and received. This layer, for example, is where connectors, cable
lengths, and signaling specifications are defined.
Layer 2 / Data Link – Layer 2 consist of two sub-layers:
• Logical Link Control (LLC) – The LLC packages bytes received from the
MAC into a format readable by the Network Layer above it.
• Media Access Control (MAC) – The MAC is concerned with obtaining
access to the network at an appropriate time; i.e., when no other machines
are communicating or when permission has been granted.
Appendix A - Network Addressing A-3
The OSI Reference Model
Together, these two sub-layer protocols are responsible for moving packets on
and off the network.
Layer 3 / Network Layer – Layer 3 is responsible for routing packets through
multiple networks. The Layer 3 protocol operates without regard to the underlying protocols in use. For example, routers operate at Layer 3.
Binary Math
A-4 Vipersat CDD-56X Series User Guide
Binary Math
Network devices communicate using BITS, where a bit is a single digit represented by a 1 or a 0, or by using BYTEs, where a byte is made up of eight bits in
any combination of 1’s or 0’s. A byte is also referred to as an octet.
Figure A-2
Bits and Bytes
An octet can be converted to or from binary using the technique shown in the
decimal conversion chart in Figure A-3. The conversion chart also shows the
decimal equivalent of the binary number.
Figure A-3
Binary to Decimal Conversion
Bits containing a 1 in Figure A-3 determine which decimal values should be
added. These decimal values, when added together, determine the decimal
equivalent for the binary number.
This is an example of changing a number expressed in binary (base 2) to its
decimal equivalent (base 10). The numeric value is the same, you have only
128 64 32 16 8 4 2 1
1
101 100 01 = 165
11 10 0 0 0 0 = 194
1111 11 11=255
128
32
4
1
_____
165
Appendix A - Network Addressing A-5
Binary Math
changed the numbering base (radix.) All digital processes are done in binary.
The conversion to decimal is done whenever binary values need to be read or
entered by humans as their decimal equivalents.
IP Addressing
A-6 Vipersat CDD-56X Series User Guide
IP Addressing
An IP (Internet Protocol) address is a unique set of numbers assigned to a device
on a network to uniquely identify that device (by its IP address).
An IP address is a unique number composed of four octets, with each octet
separated by a dot. This notation style is called dotted decimal notation.
Each IP address can be broken down into two parts, as shown in the example
below:
Example:
128.121.188.201
The first two octets are the network ID:
128.121
The second two octets are the host ID:
188.201
• Network ID - In this example, the 128.121 portion of the IP address
defines the network that a host belongs to, and is equivalent to a street
name in a mailing address.
• Host ID - The 188.201 portion of the IP address specifies a unique number
assigned to the host on the network, and is equivalent to a house number in
a mailing address.
IP Address Classes
IP addresses are assigned to classes according the schedule shown in
Figure A-4. IP address classes are assigned as follows:
Class A
• 1.x.x.x to 126.x.x.x (0 and 127 are reserved)
• 126 Class As exist
• Can have 16,777,214 hosts on each Class A
• 8-bit network number
• 24-bit node number
Class B
• 128.0.x.x to 191.254.x.x
• 16,384 Class Bs exist
• Can have 65,354 hosts on each Class B
Appendix A - Network Addressing A-7
IP Addressing
• 16-bit network number
• 16-bit node number
Figure A-4
IP Address Classes A, B, C
Class C
• 192.0.1.x to 223.255.254.x
• 2,097,152 Class Cs exist
• Can have 254 hosts on each Class C
• 24-bit network number
• 8-bit node number
Class D
• 224.0.0.0 to 239.255.255.255
• Reserved for Multicast (messages sent to many hosts).
CLASS A
CLASS B
CLASS C
2,097,152
16,384
126
Networks
Available
192-223.x.y.z
128-191.x.y.z
1-126.x.y.z
1
st
Octet
Decimal Range
254110 Class C
65,53410Class B
16,777,2140Class A
Hosts
Available
HighOrder-Bits
Address
Class
2,097,152
16,384
126
Networks
Available
192-223.x.y.z
128-191.x.y.z
1-126.x.y.z
1
st
Octet
Decimal Range
254110 Class C
65,53410Class B
16,777,2140Class A
Hosts
Available
HighOrder-Bits
Address
Class
IP Addressing
A-8 Vipersat CDD-56X Series User Guide
Class E
• 240.0.0.0 to 255.255.255.255
• Reserved for experimental use and limited broadcast
Private Network IP Addresses
RFC 1918 defines blocks of addresses for use on private networks:
• 10.0.0.0 – 10.255.255.255
• 172.16.0.0 – 172.31.255.255
• 192.168.0.0 – 192.168.255.255
Network Address Translation (NAT)
Private networks can only connect to the public Internet by using a Network
Address Translation (NAT) device (a router, for example) or a proxy server
which has been assigned a public IP address. These network devices use a
public IP address to request information from the Internet on behalf of the
private IP addressed devices on the associated private network.
Figure A-5
NAT Router Example
This use of private addresses helps to conserve public IP addresses.
Subnets
Subnets can be defined as the further segmentation of the InterNIC assigned
Network ID IP address. The amount and type of subnetting performed by the
organization is determined by the network layout.
Ethernet
Host 1
Host 2
NAT Router
Internet
192.168.0.2
192.168.0.3
192.168.0.1 Public IP
Appendix A - Network Addressing A-9
IP Addressing
In the process of subnetting, bits are borrowed from the host ID portion of an IP
address and are then given to the network ID. Then a “Subnet Mask” gets
assigned to the host along with the IP address.
Subnetting is required if the network is segmented.
Subnet Mask
The Subnet Mask is used by the host to determine if a destination IP address is
on the local or on a remote network segment. The table in Figure A-6 shows the
default subnet mask used for each class of IP address.
Figure A-6
Default Subnet Masks for IP Classes
The IP address and subnet mask work with each other to identify a network
element or device. The subnet mask, like an IP address, contains 4 octets separated by a dot (.) and looks similar to an IP address.
The subnet mask determines what bits in the IP address are being used to determine the network ID by using the Boolean math operator and in a process
called anding. Anding compares each bit value in the IP address with the bit
value in the subnet mask. The result of the anding process determines which
subnet the IP address is on. The Boolean and operator works as follows:
0 and 0 = 0
1 and 0 = 0
1 and 1 = 1
The table shown in Figure A-7 shows the anding of two binary values and the
corresponding decimal equivalents for each of the values.
11111111.11111111.11111111.00000000255.255.255.0Class C
11111111.11111111.00000000.00000000255.255.0.0Class B
11111111.00000000.00000000.00000000255.0.0.0Class A
Mask Binary ValueMask Decimal ValueAddress Class
11111111.11111111.11111111.00000000255.255.255.0Class C
11111111.11111111.00000000.00000000255.255.0.0Class B
11111111.00000000.00000000.00000000255.0.0.0Class A
Mask Binary ValueMask Decimal ValueAddress Class
CLASS A
CLASS B
CLASS C
IP Addressing
A-10 Vipersat CDD-56X Series User Guide
Figure A-7
ANDing an IP address and a subnet mask
A calculator, available from SolarWinds, performs these IP and subnet mask
calculations and can be found at:
http://support.solarwinds.net/updates/SelectProgramFree.cfm
Network Segments
A “Network Segment” is a portion of a network that is bordered by two router
interfaces as shown in Figure A-8.
Figure A-8
Network Segments
Each network segment must either be on a different network or a different
subnet. For example, if you have a single IP address available, you can change
the default mask from 255.255.255.0 to 255.255.255.192. The resulting calculation yields four subnets:
• 192.168.100.0
• 192.168.100.64
• 192.168.100.128
• 192.168.100.192
ANDing Result
Subnet Mask
IP Address
11000000.10101000.00000010.00000000192.168.2.0
11111111.11111111.11111111.00000000255.255.255.0
11000000.10101000.00000010.01000010192.168.2.66
Binary Values
Dotted Decimal
Address
ANDing Result
Subnet Mask
IP Address
11000000.10101000.00000010.00000000192.168.2.0
11111111.11111111.11111111.00000000255.255.255.0
11000000.10101000.00000010.01000010192.168.2.66
Binary Values
Dotted Decimal
Address
Appendix A - Network Addressing A-11
IP Addressing
Each of the four subnets can, in turn, support 64 members.
The example subnet used above yielded 4 subnets, but you can use a different
mask to meet the specific requirements of your network.
Default Gateways
A default gateway is a network device, usually a router, that is responsible for
routing data packets out of the local network segment.
The address of the gateway is entered into the devices on the local network,
providing them with a location to send data that is destined for another segment.
Figure A-9
Router as Default Gateway
MAC Addresses
A MAC address is a physical hardware address that gets assigned to the interface of a networking device. This address is typically created and burned into a
device’s ROM during the manufacturing process. MAC addresses are unique to
the device and are not typically user-assignable.
The MAC address is used for Layer 2 (Data Link) communications between
networking devices, and consists of 12 alpha-numeric characters as shown in
the example below:
Example: 00-3f-bf-00-01-45
IP Addressing
A-12 Vipersat CDD-56X Series User Guide
• The first six characters are issued to the organization.
• The second six characters are assigned to the hardware interface by
manufacturing.
Figure A-10
Network Node MAC Addresses
Appendix B - Automatic Switching B-1
A
PPENDIX
AUTOMATIC SWITCHING
General
Automatic switching is a feature of the VMS that allows dynamically changing
the network configuration in response to changes in either traffic type (Application switching) or network traffic loads (Load switching.)
The following material applies to the Vipersat CDM-570/570L, CDD-562L/
564/564L, and CDM-600. For purposes of simplicity, these units shall be
referred to as modem/routers.
The basic signal topology in a Vipersat network is TDM (Time Division Multiplex) outbound and Vipersat’s proprietary STDMA (Selected Time Division
Multiple Access) inbound. The STDMA slots can have their duration and bandwidth allotments varied to tailor bandwidth allocation to meet the bursty traffic
load of a typical data network.
When required, a network is switched from STDMA to SCPC. SCPC bandwidth is allocated from a bandwidth pool by the VMS to meet QoS or other
requirements for the duration of a connection. When the SCPC connection is no
longer required, the bandwidth is returned to the pool for use by another client.
This basic structure gives the VMS-controlled network its flexible, automated
network utilization and optimization capability.
The VMS has the intelligence to interpret the constantly changing statistics
gathered by the Vipersat modem/routers and uses this data to issue commands
back to these intelligent modem/routers, effectively managing the Vipersat
network operation in real time, and optimizing each user’s bandwidth usage to
General
B-2 Vipersat CDD-56X Series User Guide
meet their QoS and cost requirements within their bandwidth allocation. The
result is a stable satellite network connection that automatically responds to the
customer’s requirements while continuously monitoring and reacting to changing load, data type, and QoS requirements.
Bandwidth Allocation and Load Switching
Load Switching is the mechanism by which the Vipersat network switches a
Remote terminal from STDMA to SCPC mode based on traffic levels at the
Remote. There are two components of load switching in a Vipersat system: the
VMS (network management) and the CDM (Comtech Data Modem). The VMS
component receives switch requests from the CDM, and based on policy
settings and available resources, either grants or denies the request. Within the
CDM component, load switching is managed at either the Hub or the Remote,
based on the current mode of operation. When a Remote is in STDMA mode,
load switching for that Remote is managed by the Hub STDMA Controller.
After a Remote has been switched to SCPC mode, it manages its own switching
(or Step Up/Step Down) requests.
The basic concept for all load switching is that a running average of current
utilization is maintained, and when that utilization exceeds a pre-set threshold, a
switch is initiated. The data rate for the switch is computed by determining the
current bandwidth requirement of the Remote, and adding some percentage of
excess margin. The main difference between switching from STDMA to SCPC
and adjusting within SCPC is that in STDMA mode, the current available bandwidth is constantly changing, while in SCPC mode, it is constant between
switches. Furthermore, switches from STDMA to SCPC mode are always
caused by the traffic level exceeding the switch threshold. Within SCPC mode,
switches can be caused by traffic exceeding an upper threshold or dropping
below a lower threshold. However, in both cases the new data rate is based on
the actual traffic requirements adjusted up by the margin percentage. Also,
based on policies set in the VMS, if a Remote requests less than some threshold
amount of bandwidth, the Remote is put back into STDMA mode.
Note: If the Hub STDMA mode is GIR (Guaranteed Information Rate) or
Entry Channel, normal load switching is automatically disabled.
In GIR mode, the Remote is switched to SCPC as soon as the
GIR threshold is reached, if there is a switch rate defined. In Entry
Channel mode, the Remote is switched to SCPC as soon as the
Hub receives the first transmission from the Remote.
NOTE
Appendix B - Automatic Switching B-3
Load Switching
Load Switching
The next sections describe the principles behind Load Switching and Rate
Adjustment (Step Up/Step Down).
Bandwidth Allocation and Load Switching by the
STDMA Controller
As part of normal STDMA processing, the Hub monitors the traffic levels from
each of the Remotes for which it is allocating bandwidth. This is done using the
STDMA ACK management message (table B-1) that is transmitted at the beginning of each burst from the Remote. The STDMA ACK contains two metrics
that are used by the Hub:
1. The number of bytes received for transmission (Queued Bytes) since the last
cycle.
2. The number of bytes currently waiting to be transmitted (Bytes In Queue).
These metrics are used by the Hub for three purposes:
1. Determine the amount of STDMA bandwidth (slot size) to allocate in the
next cycle.
2. Provide statistics of the amount of activity at each Remote (Average Bytes
Received).
3. Determine if a load switch is needed.
Table B-1
STDMA ACK Message
Data
Type
Size in
Bytes
Description
Unit of
Measure
Notes:
IP 4 IP address of Remote N/A Used by Remote to identify
itself
Unsigned 4 Queued Bytes Bytes Total number of bytes queued
since last cycle (includes
possible buffer overflow)
Unsigned 4 Bytes in Queue Bytes Number of bytes currently
queued
Unsigned 1 Group Number N/A
Unsigned 1 Dropped Buffers Packets Number of packets dropped
(due to limited bandwidth)
Load Switching
B-4 Vipersat CDD-56X Series User Guide
If there is adequate upstream bandwidth available, the values of these two
metrics will be the same. However, if there is not enough bandwidth to satisfy
the traffic requirements of the Remote, or if the Remote has exceeded the maximum allocation, some data will be held for the next cycle. In this case, the
number of Bytes in Queue will start to grow and will exceed the Queued Bytes.
(In other words, the Bytes in Queue is the sum of the data not yet transmitted
plus the new data received.)
If the condition is due to a short burst of data, the backlogged data will eventually be transmitted and the system will return to a sustainable rate. However, if
the overload condition is due to long term increased activity, then the backlog
condition will continue to grow and eventually trigger an SCPC switch. If the
overload condition lasts long enough, buffer capacity will eventually be
exceeded and some data may have to be discarded.
Note: This is not necessarily bad, as it is often more effective to discard
old data than transmit it after it has become ‘stale’.
The “Bytes in Queue” metric is used to determine the STDMA bandwidth allocated (slot size) for the next cycle; the goal being to keep the data backlog to
zero. The Hub uses this metric to compute the slot size for each Remote in the
next cycle as follows:
• Fixed Mode - All Remotes get the same slot regardless of need; i.e. the
metric is not used.
• Dynamic Slot Mode - The slot size for each Remote is computed based on
the time (at the current data rate) needed to transmit all the “Bytes in
Queue”. If the result is less than the minimum slot size or more than the
maximum slot size, the slot is adjusted accordingly.
• Dynamic Cycle Mode - Available bandwidth is allocated to Remotes
proportionally, based on current need. The Bytes in Queue for each
Remote is divided by the total Bytes in Queue for all Remotes to give the
percentage allocation of bandwidth for each Remote.
• GIR (Guaranteed Information Rate) Mode - Initially computed the
same as Dynamic Cycle, except there is no maximum limit. After all
Remotes have been assigned slots, the Burst Map is checked to see if the
total cycle length exceeds one second. If not, then all requirements are
satisfied and the Burst Map is complete. However, if the cycle is greater
than one second, then the slots are adjusted proportionally so that all
Remotes receive at least their guaranteed rate plus whatever excess is still
available.
In the current design, when the one second restriction is exceeded,
Remotes without a specified GIR are reduced to the global minimum slot
NOTE
Appendix B - Automatic Switching B-5
Load Switching
size and the remaining bandwidth is distributed amongst Remotes that
have been assigned a GIR rate. This approach is based on the assumption
that Remotes that have been assigned a GIR are paying a premium and
should benefit from available excess bandwidth when needed.
Note that the GIR allocations are restricted so that the assigned GIR totals
cannot exceed available bandwidth. If this restriction is somehow violated,
then it will not be possible to properly allocate bandwidth when the
network is overloaded.
• Entry Channel Mode - This is the same as Dynamic Cycle, except that as
soon as the Hub receives an STDMA ACK, it initiates a switch to SCPC
mode based on the policy set for that Remote.
The important thing to understand about “Bytes in Queue” is that any data that
is not transmitted (i.e. does not fit) in the next slot will be reported again in the
next STDMA ACK. Thus the “Bytes in Queue” is not necessarily an accurate
measure of the actual traffic being passed through the Remote.
The “Queued Bytes” on the other hand, reflects only the data that was received
in the last cycle and thus is never duplicated (not including TCP retransmissions). This is the metric that is used for computing average load and initiating a
load switch as needed.
Before discussing how load switching is determined, it is necessary to explain
the modem/router parameters that control the switch. The screen shown in
figure B-1 shows the entries in the Automatic Switching menu at the Hub that
are used to control load switching.
Figure B-1
Auto Switching menu (Hub)
• Auto Switching - This is a Vipersat Feature which is enabled in the CDM
Features Menu. If Auto Switching is not enabled, Load Switching will be
ignored.
Load Switching
B-6 Vipersat CDD-56X Series User Guide
• Load Switching - This is a type of Automatic Switching that is based on
the amount of traffic at a Remote. If this mode is not set, then no Remote
will be switched based on load.
• STDMA Slot Capacity - This is a threshold value. When the amount of
outbound traffic at a Remote exceeds this percentage of the current
STDMA slot capacity, a load switch is initiated. It is important to
understand that in most STDMA modes, the amount of bandwidth
allocated to a Remote varies with need and thus from cycle to cycle. Thus
the amount of traffic that constitutes X% will also vary from cycle to
cycle.
• STDMA Switch Delay- This is a built-in latency that forces a Remote to
maintain an average load over some number of seconds after reaching a
switch condition before the switch is actually initiated. This prevents
switches due to momentary traffic bursts.
• Percent Allocation - This is an excess amount of bandwidth that is
allocated beyond the current traffic rate when the switch to SCPC is made.
For example, if the current average traffic at the time of the switch is 60K,
and the Percent Allocation is 10%, then the allocation will be for 60K +
6K = 66K.
Note that the Hub always allocates bandwidth in 16K blocks, so 66K
rounded up will actually be 80K in this example.
Load Switching Process
Each time the Hub receives an STDMA ACK, it computes the average load for
that Remote. This average is then compared to the bandwidth currently allocated to the Remote.
For example, if a Remote gets a 50 ms slot in an upstream that is running at
512000 bps, then it can transmit 0.050 * 512000 = 25600 bits = 3200 bytes. If
the Queued Bytes was 3000, then for that cycle, the Remote was at 3000/3200 =
93.75% of capacity. If the current cycle time is exactly 1 second, then the effec-
tive data rate of the Remote is also 25600 bits per second. However, if the cycle
time is only 500 milliseconds, then the effective data rate is actually 25600 / .5 =
51200 bits per second.
The effective data rate is important for calculating switch data rates. If the average bandwidth used exceeds the threshold percentage of available bandwidth,
then a flag is set indicating a switch is pending. At this point, the statistics are
reset and the traffic load is then computed for the time period specified by the
switch delay. At the end of this delay, if the threshold is still exceeded, a switch
is initiated. The data rate specified for the switch is determined by taking the
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