Allied Telesis AT-GS920-24 operation manual
GS920 Series
GIGABIT ETHERNET UNMANAGED SWITCHES
AT-GS920/24
AT-GS920/16
AT-GS920/8
Installation and User’s Guide
613-002385 Rev A
Copyright 2017 Allied Telesis, Inc.
All rights reserved. No part of this publication may be reproduced without prior written permission from Allied Telesis, Inc.
Microsoft and Internet Explorer are registered trademarks of Microsoft Corporation. Netscape Navigator is a registered
trademark of Netscape Communications Corporation. All other product names, company names, logos or other
designations mentioned herein are trademarks or registered trademarks of their respective owners.
Allied Telesis, Inc. reserves the right to make changes in specifications and other information contained in this document
without prior written notice. The information provided herein is subject to change without notice. In no event shall Allied
Telesis, Inc. be liable for any incidental, special, indirect, or consequential damages whatsoever, including but not limited to
lost profits, arising out of or related to this manual or the information contained herein, even if Allied Telesis, Inc. has been
advised of, known, or should have known, the possibility of such damages.
Electrical Safety and Emissions
Note
Note
Standards
This section contains the following:
“US Federal Communications Commission”
“Industry Canada”
“Translated Safety Statements” on page 4
US Federal Communications Commission
Radiated Energy for the AT-GS920/24
This equipment has been tested and found to comply with the limits for a Class A digital device
pursuant to Part 15 of FCC Rules. These limits are designed to provide reasonable protection
against harmful interference when the equipment is operated in a commercial environment.
This equipment generates, uses, and can radiate radio frequency energy and, if not installed
and used in accordance with this instruction manual, may cause harmful interference to radio
communications. Operation of this equipment in a residential area is likely to cause harmful
interference in which case the user will be required to correct the interference at his own
expense.
Radiated Energy for the AT-GS920/16 and AT-GS920/8
This equipment has been tested and found to comply with the limits for a Class B digital device
pursuant to Part 15 of FCC Rules. These limits are designed to provide reasonable protection
against harmful interference in a residential installation. This equipment generates, uses and
can radiate radio frequency energy and, if not installed and used in accordance with
instructions, may cause harmful interference to radio or television reception, which can be
determined by turning the equipment off and on. The user is encouraged to try to correct the
interference by one or more of the following measures:
• Increase the separation between the equipment and the receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver
is connected.
• Consult the dealer or an experienced radio/TV technician for help.
3
Industry Canada
Radiated Energy
This Class A digital apparatus complies with Canadian ICES-003.
Cet appareil numérique de la classe A est conforme à la norme NMB-003 du Canada.
This Class B digital apparatus complies with Canadian ICES-003.
Cet appareil numérique de la classe B est conforme à la norme NMB-003 du Canada.
Translated Safety Statements
Important: The indicates that translations of the safety statement are available in the PDF
document Translated Safety Statements posted on the Allied Telesis website at
alliedtelesis.com/support.
4
Contents
Preface ................................................................................................................................................................................11
Safety Symbols Used in this Document.........................................................................................................................12
Contacting Allied Telesis ...............................................................................................................................................13
Chapter 1: Product Description ........................................................................................................................................15
Key Features .................................................................................................................................................................16
GS920 Series Overview ................................................................................................................................................18
AT-GS920/24 Switch ..............................................................................................................................................18
AT-GS920/16 Switch ..............................................................................................................................................19
AT-GS920/8 Switch ................................................................................................................................................19
Wall and Rack Mount Brackets ..............................................................................................................................20
10/100/1000 Base-TX Twisted Pair Ports ..............................................................................................................21
Power Connector....................................................................................................................................................22
Configuration Switches and LED Descriptions ..............................................................................................................23
Power LED .............................................................................................................................................................23
Loop Prevention LED .............................................................................................................................................24
Port Mode LEDs .....................................................................................................................................................24
Port Status LEDs ....................................................................................................................................................25
AT-GS920 Feature Descriptions....................................................................................................................................26
Duplex Mode ..........................................................................................................................................................26
Store and Forward..................................................................................................................................................26
Multicast Frame Pass-Through ..............................................................................................................................27
Energy Efficiency Ethernet (EEE)...........................................................................................................................27
Loop Prevention .....................................................................................................................................................27
Flooding.......................................................................................................................
Backpressure and Flow Control .............................................................................................................................28
...........................................28
Chapter 2: Hardware Installation ......................................................................................................................................31
Reviewing Safety Precautions.......................................................................................................................................32
Selecting a Site for the Switch.......................................................................................................................................34
Planning the Installation.................................................................................................................................................35
Unpacking the Switch ....................................................................................................................................................36
AT-GS920/24 Shipping Contents ...........................................................................................................................36
Unpacking the AT-GS920/24 Bracket Kit ...............................................................................................................37
AT-GS920/16 Shipping Contents ...........................................................................................................................38
AT-GS920/8 Shipping Contents .............................................................................................................................39
Installing the Switch on a Table or Desktop...................................................................................................................40
Installing the Switch on a Wall .......................................................................................................................................41
Guidelines for Installing the Switch on a Wall.........................................................................................................41
Items Need for Wall Installation..............................................................................................................................41
Wall Installation of AT-GS920/24 ...........................................................................................................................42
Wall Installation of AT-GS920/16 or AT-GS920/8 ..................................................................................................44
Installing the Switch in an Equipment Rack ...................................................................................................................47
Guidelines for Installing the Switch in a Rack.........................................................................................................47
What to Prepare for Installation in a Rack..............................................................................................................47
Rack Installation of AT-GS920/24 ..........................................................................................................................47
Rack Installation of AT-GS920/16 or AT-GS920/8.................................................................................................49
Cabling the Switch .........................................................................................................................................................54
Powering On the Switch ................................................................................................................................................55
5
Contents
Chapter 3: Switch Configuration ......................................................................................................................................57
Configuration Switch and LED Locations ......................................................................................................................58
Reset Ports to Factory Default Configuration ................................................................................................................59
Feature Configuration....................................................................................................................................................61
Multicast Frame Pass-Through ..............................................................................................................................61
Energy Efficiency Ethernet (EEE)...........................................................................................................................64
Loop Prevention .....................................................................................................................................................66
Flooding..................................................................................................................................................................68
Flow Control ...........................................................................................................................................................70
Ethernet Port Configuration ...........................................................................................................................................72
ALL Ports Configuration .........................................................................................................................................73
EACH Individual Port Configuration .......................................................................................................................75
MDI/MCI-X Configuration .......................................................................................................................................76
Chapter 4: Troubleshooting ..............................................................................................................................................79
Appendix A: Technical Specifications .............................................................................................................................81
Physical Specifications ..................................................................................................................................................81
Environmental Specifications.........................................................................................................................................81
Safety ............................................................................................................................................................................82
Electromagnetic Emissions Certifications......................................................................................................................83
EMI (Electro Magnetic Interference).......................................................................................................................83
ICES-003 Class A or B...........................................................................................................................................83
EN55032: 2012/AC: 2013 Class A or B .................................................................................................................83
CISPR 32 ...............................................................................................................................................................83
RCM AS/NZS CISPR 32: 2013 ..............................................................................................................................83
ANATEL .................................................................................................................................................................83
Immunity.................................................................................................................................................................83
Electrical Safety......................................................................................................................................................83
EMS (Electromagnetic Susceptibility) EN55024:2010...................................................................................................84
Power Specifications .....................................................................................................................................................84
RJ-45 Twisted Pair Port Connectors .............................................................................................................................85
Appendix B: AT-GS920/24 Switch Wall Mount Installation ............................................................................................87
Unpacking the AT-BRKT-J22 Wall Mount Kit ................................................................................................................88
Installing a Switch Using the AT-BRKT-J22 Wall Mount Kit ..........................................................................................89
What to Prepare .....................................................................................................................................................89
Installing a Switch Using the AT-BRKT-J22 Brackets ............................................................................................89
Appendix C: Loop Prevention Feature ............................................................................................................................95
Guidelines for Loop Prevention .....................................................................................................................................96
Root Switch ...................................................................................................................................................................97
Root Switch Overview ............................................................................................................................................97
Switch Priority.........................................................................................................................................................97
Root Switch ............................................................................................................................................................97
Non-root Switch......................................................................................................................................................97
Examples of Selecting a Root Switch.....................................................................................................................98
Detecting and Blocking a Loop ......................................................................................................................................99
Loop Detection .......................................................................................................................................................99
Blocked Port Selection Criteria...............................................................................................................................99
Port Blocked Within a LAN ...................................................................................................................................100
Port Blocked on One Switch.................................................................................................................................101
Blocking a Port Affected by an External Loop ......................................................................................................102
Hop Count Limitation ...................................................................................................................................................103
6
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
List of Figures
Figure 1: AT-GS920/24 Front Panel..................................................................................................................................... 18
Figure 2: AT-GS920/24 Rear Panel......................................................................................................................................19
Figure 3: AT-GS920/16 Front Panel..................................................................................................................................... 19
Figure 4: AT-GS920/16 Rear Panel......................................................................................................................................19
Figure 5: AT-GS920/8 Front Panel....................................................................................................................................... 20
Figure 6: AT-GS920/8 Rear Panel........................................................................................................................................20
Figure 7: AT-GS920/8 Front Panel Configuration DIP Switches and LEDs .........................................................................23
Figure 8: Installation of Rubber Feet ....................................................................................................................................40
Figure 9: Removing Feet From the Chassis Bottom.............................................................................................................42
Figure 10: Attaching the Brackets to the AT-GS920/24 Switch ............................................................................................42
Figure 11: Marking the Screw Hole Locations......................................................................................................................43
Figure 12: Driving the Screws through the Holes ................................................................................................................. 43
Figure 13: Removing the Rubber Feet .................................................................................................................................45
Figure 14: Marking the Screw Hole Locations......................................................................................................................45
Figure 15: Driving the Screws through the Holes ................................................................................................................. 46
Figure 16: Placing the Switch into the Brackets ...................................................................................................................46
Figure 17: Attaching the Extension to the Bracket................................................................................................................47
Figure 18: Removing Rubber Feet .......................................................................................................................................48
Figure 19: Attaching the Brackets to the Switch ................................................................................................................... 48
Figure 20: Attaching the Switch to an Equipment Rack........................................................................................................ 48
Figure 21: Attaching Handles to Brackets ............................................................................................................................51
Figure 22: Attaching Brackets to Plates................................................................................................................................51
Figure 23: Attaching Cable Tray to Plates............................................................................................................................52
Figure 24: Attaching the Plates to the Switch ....................................................................................................................... 52
Figure 25: Attaching the Switch to Equipment Rack.............................................................................................................53
Figure 26: Initial Power-ON Sequence .................................................................................................................................55
Figure 27: Securing the Power Cord Using Tie-wraps .........................................................................................................56
Figure 28: Front Panel Configuration Switches and LEDs ...................................................................................................58
Figure 29: Setting the Switch to Port Configuration Mode....................................................................................................59
Figure 30: DIP Switch Setting for Enabling Multicast Frame Pass-Through ........................................................................ 62
Figure 31: DIP Switch Settings for Disabling Multicast Frame Pass-Through......................................................................63
Figure 32: DIP Switch Settings for Enabling EEE.................................................................................................................64
Figure 33: DIP Switch Settings for Disabling EEE................................................................................................................65
Figure 34: DIP Switch Settings for Enabling Loop Prevention....................................................................
Figure 35: DIP Switch Settings for Disabling Loop Prevention............................................................................................. 67
Figure 36: DIP Switch Settings for Enabling Flooding ..........................................................................................................68
Figure 37: DIP Switch Settings for Disabling Flooding ......................................................................................................... 69
Figure 38: DIP Switch Settings for Enabling Flow Control....................................................................................................70
Figure 39: DIP Switch Settings for Disabling Flow Control...................................................................................................71
Figure 40: DIP Switch Settings for Configuring All Ports ......................................................................................................73
Figure 41: Port Configuration ...............................................................................................................................................74
Figure 42: DIP Switch Settings for Configuring An Individual Port .......................................................................................75
Figure 43: DIP Switch Settings for ALL Port Configuration ..................................................................................................77
Figure 44: DIP Switch Settings for Individual Port Configuration.......................................................................................... 78
Figure 45: RJ-45 Connector and Port Pin Layout.................................................................................................................85
Figure 46: Removing AT-GS920/24 Rubber Feet ................................................................................................................89
Figure 47: Marking the Screw Hole Locations......................................................................................................................90
Figure 48: Driving the Screws through the Holes ................................................................................................................. 91
Figure 49: Placing the Switch into the Brackets ...................................................................................................................91
Figure 50: Marking the Screw Hole Locations......................................................................................................................92
Figure 51: Driving the Screws through the Holes ................................................................................................................. 93
Figure 52: Case 1: Selecting a Root Switch .........................................................................................................................98
Figure 53: Case 2: Selecting a Root Switch .........................................................................................................................98
Figure 54: Case 1: Selecting a Port to be Blocked .............................................................................................................100
..........................66
7
Figures
Figure 55: Case 2: Selecting a Port to be Blocked .............................................................................................................100
Figure 56: Case 3: Selecting a Port to be Blocked .............................................................................................................101
Figure 57: Blocked Port on One AT-GS920/8 Switch.........................................................................................................101
Figure 58: Blocked Port on One AT-GS920/16 or AT-GS920/24 Switch............................................................................101
Figure 59: Blocking a Port Affected by an External Loop ...................................................................................................102
8
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
List of Tables
Table 1. Wall and Rack Mount Brackets .............................................................................................................................20
Table 2. Twisted Pair Cabling and Distances .....................................................................................................................22
Table 3. Power LED ...........................................................................................................................................................23
Table 4. Loop Prevention LED ...........................................................................................................................................24
Table 5. Port Mode LEDs ...................................................................................................................................................24
Table 6. Port Status LEDs for Normal and Configuration Modes .......................................................................................25
Table 7. Flow Control - Supported Speeds .........................................................................................................................29
Table 8. Twisted Pair Cabling and Distances .....................................................................................................................35
Table 9. AT-GS920/24 Shipping Box Contents ..................................................................................................................36
Table 10. Components in the AT-GS920/24 Bracket Kit ....................................................................................................37
Table 11. AT-GS920/16 Shipping Box Contents ................................................................................................................38
Table 12. AT-GS920/8 Shipping Box Contents ..................................................................................................................39
Table 13. Components in the AT-BRKT-J23 Wall Mount Kit ..............................................................................................44
Table 14. Components in Rack Mount Kit ..........................................................................................................................49
Table 15. EEE Support for Port Speed/Link Configuration .................................................................................................65
Table 16. MDI Pin Signals (10Base-T or 100Base-TX) ......................................................................................................85
Table 17. MDI-X Pin Signals (10Base-T or 100Base-TX) ..................................................................................................85
Table 18. Pin Signals (1000 Mbps) .....................................................................................................................................86
Table 19. Components in the AT-BRKT-J22 Wall Mount Kit ..............................................................................................88
Table 20. Switch Priority .....................................................................................................................................................97
Table 21. Maximum Hop Count ........................................................................................................................................103
9
Tables
10
Preface
This Preface contains the following sections:
“Safety Symbols Used in this Document” on page 12
“Contacting Allied Telesis” on page 13
This manual is the installation and user’s guide for the GS920 Series
Gigabit Ethernet Unmanaged Switches. The switch models included in this
manual are:
– AT-GS920/24
– AT-GS920/16
– AT-GS920/8
11
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
Note
Caution
Warning
Safety Symbols Used in this Document
This document uses the following conventions:
Notes provide additional information.
Cautions inform you that performing or omitting a specific action
may result in equipment damage or loss of data.
Warnings inform you that performing or omitting a specific action
may result in bodily injury.
12
Contacting Allied Telesis
If you need assistance with this product, you may contact Allied Telesis
technical support by going to the Support & Services section of the Allied
Telesis web site at www.alliedtelesis.com/support. You can find links for
the following services on this page:
24/7 Online Support - Enter our interactive support center to
search for answers to your questions in our knowledge database,
check support tickets, learn about Return Merchandise
Authorization (RMA), and contact Allied Telesis technical experts.
USA and EMEA phone support - Select the phone number that
best fits your location and customer type.
Hardware warranty information - Learn about Allied Telesis
warranties and register your product online.
Replacement Services - Submit an RMA request via our interactive
support center.
Preface
Documentation - View the most recent installation guides, user
guides, software release notes, white papers and data sheets for
your product.
Software Updates - Download the latest software releases for your
product.
For sales or corporate contact information, go to
www.alliedtelesis.com/purchase and select your region.
13
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
14
Chapter 1
Product Description
This chapter contains the follows sections:
“Key Features” on page 16
“GS920 Series Overview” on page 18
“Configuration Switches and LED Descriptions” on page 23
“AT-GS920 Feature Descriptions” on page 26
15
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
Key Features
The GS920 Series switches have the following key features:
– Complies with IEEE802.3,IEEE802.3u,IEEE802.3ab, IEEE802.3x
– Supports 8 auto-negotiation 10/100/1000Mbps ports for
AT-GS920/8
– Supports 16 auto-negotiation 10/100/1000Mbps ports for
AT-GS920/16
– Supports 24 auto-negotiation 10/100/1000Mbps ports for
AT-GS920/24
– Supports Store-and-forward packet forwarding
– Supports HOL blocking prevention
– Supports jumbo frames of 9216 bytes (inclusive) without frame
loss and drops packets that are larger than 9216 bytes (exclusive)
– MAC address entries:
– AT-GS920/8: up to 4K
– AT-GS920/16: up to 8K
– AT-GS920/24: up to 8K
– Supports link down and cable length power saving function
– Supports Multicast Frame Pass-Through which can be enabled or
disabled by setting a DIP switch
– Supports AUTO MDI/MDI-X on all ports. All ports are capable of
being configured for Fixed MDI-X except the last port which is
configured for Fixed MDI. This feature is enabled and disabled by
setting DIP switches and using a front panel push button.
– Supports IEEE 802.3x flow control in full-duplex operation and
backpressure flow control in half-duplex operation. This feature is
enabled or disabled by setting a DIP switch
– Supports loop detection and prevention function - can be enabled
or disabled by setting a DIP switch
– Supports IEEE 802.3az EEE function only for 100M/1000M link
speed - can be enabled or disabled by setting a DIP switch (EEE
for 10M is not supported)
– Supports Flooding mode - can be enabled or disabled by setting a
DIP switch
– Supports port speed and half/full duplex configurable function by
setting the DIP switches and using a front panel push button.
– Each chassis has no fan.
– Internal switching power supply
16
Chapter 1: Product Description
– RoHS Compliant
– 0 to 50 degree C operating temperature
– Wall/Rack mount kit is provided within the AT-GS920/24 ship kit
– Support both wall mount and rack mount functions for RoW
17
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
GS920 Series Overview
The GS920 Series switch includes the following models and hardware
features:
“AT-GS920/24 Switch”
“AT-GS920/16 Switch” on page 19
“AT-GS920/8 Switch” on page 19
“Wall and Rack Mount Brackets” on page 20
“10/100/1000 Base-TX Twisted Pair Ports” on page 21
“Power Connector” on page 22
Each model uses an internal high efficiency PSU and a low power chipset
to conform with the Allied Telesis commitment to environmentally friendly
processes. They can all be installed on a desktop, mounted on a wall or
mounted in a 19” rack.
AT-GS920/24
Switch
Each switch features support for Multi-Cast Frame Pass-Through,
IEEE802.3az Energy Efficiency power savings, Loop Detection and
Prevention, Flooding Mode and Flow Control. These features are each
configurable by dedicated front panel DIP switches. See “AT-GS920
Feature Descriptions” on page 26 and “Feature Configuration” on page 61
for more information.
In addition, the switch ports can be individually or collectively configured
for auto-negotiation or manual duplex and speed settings. The highest
number port’s default setting is MDI/MDI-X and can be forced to fixed MDI
while all of the other ports can be forced to MDI/MDI-X. These port
settings are configured by a combination of the front panel DIP switches
and push buttons. See “Ethernet Port Configuration” on page 72 for more
information.
The AT-GS920/24 switch can be installed on a desktop, a wall, or in a
19-inch equipment rack. To mount the switch on the wall or in an
equipment rack, use the brackets that are provided with the switch.
The AT-GS920/24 switch has 24 each 10/100/1000Base-TX twisted pair
ports as shown in Figure 1.
Figure 1. AT-GS920/24 Front Panel
18
Chapter 1: Product Description
The AT-GS920/24 switch has an internal power supply with a single AC
power supply socket on the rear panel as shown in Figure 2.
x
Figure 2. AT-GS920/24 Rear Panel
AT-GS920/16
Switch
The AT-GS920/16 switch can be installed on a desktop, mounted on a
wall, or in a 19-inch equipment rack. To mount the switch on the wall or an
equipment rack, you must order separate bracket kits. For more
information, see Table 1, “Wall and Rack Mount Brackets” on page 20.
The AT-GS920/16 switch has 16 each 10/100/1000Base-TX twisted pair
ports on the front panel as shown in Figure 3.
x
Figure 3. AT-GS920/16 Front Panel
The AT-GS920/16 switch has an internal power supply with a single AC
power supply socket on the rear panel as shown in Figure 4.
x
AT-GS920/8
Switch
Figure 4. AT-GS920/16 Rear Panel
The AT-GS920/8 switch can be installed on a desktop, mounted on a wall,
or mounted in a 19-inch equipment rack. To mount the switch on the wall
or in an equipment rack, use the brackets that are provided with the
switch.
The AT-GS920/8 switch has 8 each 10/100/1000Base-TX twisted pair
ports as shown in Figure 5.
19
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
x
The AT-GS920/8 switch has an internal power supply with a single AC
power supply socket on the rear panel as shown in Figure 6.
x
Figure 5. AT-GS920/8 Front Panel
Figure 6. AT-GS920/8 Rear Panel
Wall and Rack
Mount Brackets
Table 1 shows brackets options for the GS920 Series switches.
Table 1. Wall and Rack Mount Brackets
Model Wall Mount Rack Mount
AT-GS920/24 Use the Wall/Rack
Mount Kit provided in the
shipping box for all
Use the Wall/Rack Mount
Kit provided in the shipping
box for all installations.
installations except in
Japan.
NOTE: For Japan
installations only, use the
optional AT-BRKT-J22
Wall Mount Kit instead
which must be ordered
separately.
AT-GS920/16 Use AT-BRKT-J23 wall
mount kit.
NOTE: This kit must be
ordered separately.
Optional AT-RKMT-J05
optional 19” rack mount kit.
NOTE: This kit must be
ordered separately.
AT-GS920/8 Use AT-BRKT-J23 wall
mount kit.
NOTE: This kit must be
ordered separately.
Optional AT-RKMT-J08
optional 19” rack mount kit.
NOTE: This kit must be
ordered separately.
20
Chapter 1: Product Description
Note
10/100/1000
Base-TX Twisted
Pair Ports
The GS920 Series switches are equipped with multiple
10/100/1000Base-TX twisted pair ports
Connector
All twisted pair ports feature 8-pin RJ-45 connectors. For the port pinouts,
see “RJ-45 Twisted Pair Port Connectors” on page 85.
Speed
The ports are 10Base-T, 100Base-TX, and 1000Base-T compliant and
capable of 10 Mbps, 100 Mbps, and 1000 Mbps speeds. The ports default
configuration is IEEE 802.3u Auto-Negotiation compliant. With
Auto-Negotiation enabled, the switch automatically matches the highest
possible common speed between the switch port and its end-node. For
example, if an end-node is capable of only 10 Mbps, the switch sets the
port connected to the end-node to 10 Mbps.
Alternatively, each port can be manually configured to 10 Mbps, 100
Mbps, and 1000 Mbps via the switches and push buttons. See
“MDI/MDI-X” for the corresponding description of the MDI-X configuration.
Duplex Mode
Each twisted pair port on the switch can operate in either half- or
full-duplex mode at 100/10 Mbps and full-duplex mode only when
operating at 1000 Mbps. The duplex default settings of the twisted pair
ports are IEEE 802.3u-compliant and automatically negotiate the duplex
mode setting.
In order for the switch to automatically set the duplex mode for each
port correctly at 100/10 Mbps, the end-nodes that you connect to the
switch ports also need to be configured for Auto-Negotiation.
Otherwise, a duplex mode mismatch can occur, affecting network
performance. For further information, refer to “Duplex Mode” on
page 26.
With the DIP switches and push buttons, each port can be manually
configured for one of the following duplex modes: Auto-Negotiation,
1000M/Full, 100M/Full, 100M/Half, 10M/Full, 10M/Half.
21
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
Note
Note
MDI/MDI-X
The default configuration for all of the twisted pair ports on the switch is
auto-MDI/MDI-X where the ports automatically configure themselves as
MDI or MDI-X when connected to an end-node. Auto-MDI/MDI-X is in
effect when the ports are configured for Auto-Negotiation or 1000M/FULL.
In this mode, you can use a straight-through twisted pair cable to connect
any network device to a port.
See “Ethernet Port Configuration” on page 72 for the port
configuration procedures.
You can manually force the highest numbered port to fixed MDI by using
one of the front panel push buttons. When all of the ports are configured at
once, then the configuration for all other ports is fixed MDI-X.
When a port is manually configured for a speed of 10M or 100M, then that
port is also configured for fixed MDI-X except in the case of the highest
numbered port, which is set to fixed MDI.
Cabling
Table 2 contains the cabling specifications for the twisted pair ports.
Table 2. Twisted Pair Cabling and Distances
Maximum
Speed Type of Cable
10 Mbps Two-pair Category 3 or better
unshielded twisted pair cable
100 Mbps Two-pair Category 5 or better
unshielded twisted pair cable
1000 Mbps Four-pair Category 5e or better
unshielded twisted pair cable
Operating
Distance
100 m (328 ft)
100 m (328 ft)
100 m (328 ft)
Power Connector The AT-GS920 switches have a single AC power supply socket on the
back panel. Use the AC power cord that is supplied with the switch.
To power the switch ON or OFF, connect or disconnect the power
cord from the switch.
22
Configuration Switches and LED Descriptions
Note
The LEDs display status information when the switch is in a Normal
operating mode or in a Configuration mode.
The GS920 Series LEDs and configuration switches are located on the
front panel of the chassis. Refer to Figure 7, “AT-GS920/8 Front Panel
Configuration DIP Switches and LEDs” for their locations.
Chapter 1: Product Description
Figure 7. AT-GS920/8 Front Panel Configuration DIP Switches and LEDs
The front panel Configuration switches and LED locations are shown
for the AT-GS920/8 switch. Similar switch and LED layouts can also
be found on the AT-GS920/24 and AT-GS920/16 front panels.
The following tables describe the LED groups on the GS920 Series
switches:
“Power LED”
“Loop Prevention LED” on page 24
“Port Mode LEDs” on page 24
“Port Status LEDs” on page 25
Power LED The Power LED indicates the status of the chassis power being ON or
OFF. See Table 3, “Power LED”.
Table 3. Power LED
LED State Description
PWR
Green ON Power ON
OFF Power OFF
23
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
Loop Prevention
LED
The Loop Prevention LED indicates if the Loop Prevention feature is
enabled or disabled and if a loop condition has been detected and blocked
on one of the Ethernet ports. See Table 4, “Loop Prevention LED”.
Table 4. Loop Prevention LED
LED State Description
Green ON Enable Loop Prevention
LOOP
Prevention
Green Blinking Loop condition detected
OFF Disable Loop Prevention
Port Mode LEDs See “Ethernet Port Configuration” on page 72 for the configuration
procedures and more information.
When the Ethernet ports are being configured, the Port Mode LEDs
indicate their configuration. See Table 5, “Port Mode LEDs”.
Table 5. Port Mode LEDs
LED State Description
Select Enabled - FORCE MDI for
Force MDI
Green ON
a,b
the highest Ethernet port and fixed
MDI-X for all other Ethernet ports.
OFF Select Auto MDI/MDI-X
Auto-Negotiation Green ON Select Enabled - Auto-Negotiation
OFF Select Disabled - Auto-Negotiation
Duplex Green ON Select Full Duplex Mode
OFF Select Half Duplex Mode
Green ON Select 1000M speed
Speed
Amber ON Select 100M speed
OFF Select 10M speed
ALL Mode LEDs Green
Blinking
a. When the port speed is configured for Auto Negotiation or 1000M/Full, the
MODE/FORCE MDI push button affects the FORCE MDI LED as described
above.
b.
When the port speed is configured individually or altogether for 100M or
10M, the respective ports are always configured as follows:
AT-GS920/8: Ports 1-7 => MDI-X, Port 8 => MDI
AT-GS920/16: Ports 1-15 => MDI-X, Port 16 => MDI
AT-GS920/24: Ports 1-23 => MDI-X, Port 24 => MDI
Reset to default indication when
blinking on all 4 MODE LEDs
24
Chapter 1: Product Description
Port Status LEDs Two ports status LEDs are assigned to each port. When the switch is in
the Normal operating mode, the upper port LED indicates the Link/Activity
status, and the lower LED indicates the port speed and loop detection
status. When the switch is in the Configuration mode, the upper port LED
is OFF and the lower LED indicates if the specific port is selected to be
configured. See Table 6, “Port Status LEDs for Normal and Configuration
Modes”.
Table 6. Port Status LEDs for Normal and Configuration Modes
Mode
Normal Mode
Port LED
Position
LED State Description
Upper LEDs Link/Activity
SPEED
Lower LEDs
LOOP
Indication
Green ON Valid Link has been established
Green
Transmitting or Receiving Data
Blinking
OFF No Link
Green ON 1000Mbps Link
Amber ON 100Mbps Link
OFF 10Mbps Link or No Link
1000Mbps Link. A loop condition
Green
Blinking
is detected and the port is
automatically blocked by switch to
relieve the loop.
100Mbps or 10Mbps Link. A loop
Amber
Blinking
condition is detected and the port
is automatically blocked by switch
to relieve the loop.
Configuration
Mode
Lower LEDs
a
Green
Blinking
Port Select
Indicates the port is selected and
b
eligible to be configured with front
panel DIP switches.
OFF Port is not selected.
a. The Upper LED for each port is not used in the Configuration Mode.
b. When all of the Lower LEDs are blinking together in the Configuration Mode, then all of the Ethernet ports are
eligible to be configured at once. When only one of the Lower LEDs is blinking, then that port is eligible to be
individually configured.
25
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
Note
AT-GS920 Feature Descriptions
An Ethernet switch interconnects network devices, such as workstations,
printers, routers, and other Ethernet switches, so that they can
communicate with each other by sending and receiving Ethernet frames.
This section discusses the following features:
“Duplex Mode”
“Store and Forward”
“Multicast Frame Pass-Through”
“Energy Efficiency Ethernet (EEE)”
“Loop Prevention”
“Flooding”
“Backpressure and Flow Control”
Duplex Mode Duplex mode refers to how an end node receives and transmits data. If an
end node can receive or transmit data, but not both simultaneously, it is
operating in half-duplex mode. If an end node can both receive and
transmit data simultaneously, the end node is operating in full-duplex
mode. As such an end node capable of operating in full-duplex can handle
data much faster than an end node that can only operate in half-duplex
mode.
Store and
Forward
The twisted pair ports on the GS920 Series switch can operate in half- or
full-duplex mode for 10/100 Mbps. They are IEEE 802.3u-compliant and
use Auto-Negotiation to set the duplex mode setting for you automatically.
In order for a switch port to successfully Auto-Negotiate its duplex
mode with a 10 or 100 Mbps end-node, the end-node should also be
configured for Auto-Negotiation. Otherwise, a duplex mode
mismatch can occur. A switch port using Auto-Negotiation defaults
to half-duplex if it detects that the end-node is not using
Auto-Negotiation. This results in a mismatch if the end-node is
operating at a fixed duplex mode of full-duplex.
The GS920 Series switch uses store-and-forward as the method for
receiving and transmitting frames. When an Ethernet frame is received on
a switch port, the switch does not retransmit the frame out the destination
port until it has received the entire frame and stored the frame in a port
buffer. It then examines the frame to determine if it is a valid frame. Invalid
frames such as fragments or runts are discarded by the switch. This
insures that only valid frames are transmitted out the switch ports and that
damaged frames are not propagated on your network.
26
Chapter 1: Product Description
Note
Note
Note
Multicast Frame
Pass-Through
Energy Efficiency
Ethernet (EEE)
The Multicast Frame Pass-Through function includes EAP, BPDU frame
types and others.
When Multicast Frame Pass-Through is enabled, the Flooding
feature must be disabled.
This feature can be enabled or disabled by setting DIP switch # 1
(MULTICAST PASSTHRU). See “Multicast Frame Pass-Through” on
page 61 for the procedure to enable and disable this feature.
The GS920 Series switches support IEEE 802.3az Energy Efficiency
Ethernet (EEE) when the twisted pair ports are operating at a speed of
100Mbps or 1000Mbps. When EEE is enabled on the switch, the power
consumption to keep links at a these speeds is reduced during periods of
low data activity.
When a GS920 Series switch is operating 10Mbps, EEE is not
supported.
This feature can be enabled or disabled by setting DIP switch # 2 (EEE).
See “Energy Efficiency Ethernet (EEE)” on page 64 for the procedure to
enable and disable this feature.
Loop Prevention The GS920 Series switches support Loop Prevention. When a physical
network has more than one path between two endpoints, a network loop
occurs. This results is a broadcast storm which slows all other Ethernet
traffic on the network. With Loop Prevention enabled, the GS920 Series
switches blocks the specific switch port that is associated with the
excessive traffic.
Please refer to Appendix C, “Loop Prevention Feature” on page 95 for a
more detailed explanation of this feature,
Flow Control must be disabled when Loop Prevention is enabled.
Loop Prevention is not supported when Flow Control is also
enabled.
This feature can be enabled or disabled by setting DIP switch # 3 (Loop).
See “Loop Prevention” on page 66 for the procedure to enable and disable
this feature.
27
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
Note
Note
Flooding The Flooding mode allows all received legal frames to be switched
through the GS920 Series switch.
The Flooding mode has a higher priority and takes precedence over
the Multicast Frame Pass-Through feature. If the Multicast Frame
Pass-Through feature is desired, then the Flooding feature must be
disabled.
This feature can be enabled or disabled by setting DIP switch # 4
(Flooding). See “Flooding” on page 68 for the procedure to enable and
disable this feature.
The GS920 series switches DO NOT SUPPORT the combination of
Flooding & Flow Control. If both the flooding and flow control
features are enabled at once, traffic will be stopped by pause
packet.
For example: 1G traffic --> 10Mbps,100Mbps, then 1G traffic will be
10Mbps because of pause packet.
Backpressure and
Flow Control
To maintain the orderly movement of data between the end-nodes, an
Ethernet switch may periodically need to signal an end-node to stop
sending data. This can occur under several circumstances. For example, if
two end-nodes are operating at different speeds, the switch, while
transferring data between the end-nodes, might need to instruct the faster
end-node to stop transmitting data to allow the slower end-node to catch
up. An example of this would be when a server operating at 100 Mbps is
sending data to a workstation operating at only 10 Mbps.
How a switch signals an end-node to stop transmitting data differs
depending on the duplex mode of the end-node and switch port. A twisted
pair port operating in half-duplex mode stops an end-node from
transmitting data by forcing a collision. A collision on an Ethernet network
occurs when two end-nodes attempt to transmit data using the same data
link at the same time. A collision causes an end-node to stop sending
data, wait for a brief period of time, and then retransmit the same data.
Once the switch is ready to receive data again, the switch stops forcing
collisions. This is referred to as backpressure.
A port operating in full-duplex mode uses PAUSE frames, as specified in
the IEEE 802.3x standard, to stop the transmission of data from an
end-node. Whenever the switch wants an end-node to stop transmitting
data, it issues this frame. The frame instructs the end-node to cease
transmission for a period of time specified within the frame. The switch
continues to issue PAUSE frames until it is ready again to receive data
from the end-node. This is referred to as flow control. Refer to Table 7,
“Flow Control - Supported Speeds” on page 29 for Backpressure and Flow
28
control support vs. port speed.
Note
Table 7. Flow Control - Supported Speeds
Chapter 1: Product Description
Speed
Configuration
Pause Frame Back Pressure
Auto Negotiation
1G Full Auto
100M Full
100M Half
10M Full
10M Half
This feature can be enabled or disabled by setting DIP switch # 5 (FLOW
CTRL). See “Flow Control” on page 70 for the procedure to enable and
disable this feature.
The GS920 series switches DO NOT SUPPORT the combination of
Flooding & Flow Control. If both the flooding and flow control
features are enabled at once, traffic will be stopped by pause
packet.
For example: 1G traffic --> 10Mbps,100Mbps, then 1G traffic will be
10Mbps because of pause packet.
Not Support Not Support
Not Support Support
Not Support Not Support
Not Support Support
Flow Controllable
Support Support
Support Not Support
29
GS920 Series Gigabit Ehternet Switch Installation and User’s Guide
30
Loading...