2N BRI Lite Enterprise User Manual v1.3
www.2n.czFirmware
Version
2N BRI Lite/Enterprise
®
BRI-VoIP-GSM/UMTS Gateway
User Manual
1.3
1.5.0
The 2N TELEKOMUNIKACE joint-stock company is a Czech manufacturer and supplier of
telecommunications equipment.
The product family developed by 2N TELEKOMUNIKACE a.s. includes GSM gateways, private
branch exchanges (PBX), and door and lift communicators. 2N TELEKOMUNIKACE a.s. has
been ranked among the Czech top companies for years and represented a symbol of stability
and prosperity on the telecommunications market for almost two decades. At present, we
export our products into over 120 countries worldwide and have exclusive distributors on all
continents.
2N is a registered trademark of 2N TELEKOMUNIKACE a.s.. Any product and/or other
®
names mentioned herein are registered trademarks and/or trademarks or brands protected
by law.
2N TELEKOMUNIKACE administers the FAQ database to help you quickly find information and
to answer your questions about 2N products and services. On www.faq.2n.cz you can find
information regarding products adjustment and instructions for optimum use and procedures
„What to do if...“.
Declaration of Conformity
2N TELEKOMUNIKACE hereby declares that the 2N BRI Lite/Enterprise product complies
®
with all basic requirements and other relevant provisions of the 1999/5/EC directive. For the
full wording of the Declaration of Conformity see the CD-ROM enclosed and at www.2n.cz.
The 2N TELEKOMUNIKACE company is the holder of the ISO 9001:2009 certificate. All
development, production and distribution processes of the company are managed by this
standard and guarantee a high quality, technical level and professional aspect of all our
Content
1. Product Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
1.1 Product Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
1.2 Safety Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
1.3 Upgrade . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
1.4 Terms and Symbols Used . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
2. Description and Installation . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.1 Before You Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
2.2 Brief Installation Guide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.3 Available ISDN BRI Extension Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.4 IP Voice Transmission . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.5 Types of 2N® BRI Enterprise Connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
3. Making Calls via BRI Gateway . . . . . . . . . . . . . . . . . . . . . . . . 31
3.1 Supported 2N BRI Gateway Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32
3.2 Call Routing Principles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
4. First Launch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
4.1 Ethernet Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
4.2 Licence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40
4.3 Firmware Version . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41
4.4 Factory Reset . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
4.5 Basic Configuration – Step by Step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43
5. Introduction to Configuration Interface . . . . . . . . . . . . . . . . 44
5.1 Configuration Web Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45
6. Configuration Via Terminal . . . . . . . . . . . . . . . . . . . . . . . . . . 70
6.1 LAN Communication Setting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
6.2 GSM Gateway Behaviour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
6.3 List of Terminal AT Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73
6.4 Status Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80
6.5 LOG Files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86
6.6 Call Data Records (CDR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88
6.7 Statistics - Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89
7. Technical Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
8. Supplementary Information . . . . . . . . . . . . . . . . . . . . . . . . . . 93
8.1 Directives, Laws and Regulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 94
8.2 Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95
8.3 List of Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
8.4 General Instructions and Cautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98
1. Product Overview
In this section, we introduce the product, outline its2N BRI Lite / Enterprise
®
application options and highlight the advantages following from its use.
Here is what you can find in this section:
1.1 Product Description
1.2 Safety Precautions
1.3 Upgrade
1.4 Terms and Symbols Used
®
52N TELEKOMUNIKACE a.s., www.2n.cz
1.1 Product Description
The GSM gateway provides direct interconnection of the2N Enterprise / BRI Lite
®
ISDN with GSM networks. It can also be used for direct interconnection of an ISDN PBX
with a GSM network, ISDN telephone set and, via a terminal adapter, with an analogue
apparatus or coin machine. The voice mode, i.e. outgoing and incoming calls, is the
basic function of the gateway. Moreover, the BRI gateway provides connection to the
VoIP–SIP networks. The gateway is equipped with all functions necessary for this mode
and is very user–friendly. In addition, allows you to 2N BRI Enterprise / BRI Lite
®
send and receive SMS messages. No additional devices (an external telephone, e.g.)
are required for normal operation. All gateway parameters can be set using a
configuration program (on an enclosed CD), or using the AT commands. Programmable
parameters are pre–set to make it possible to make calls as soon as the supply cable,
antenna a SIM cards are connected.
2N® BRI Enterprise / 2N® BRI Lite Differences
The and gateways are based on one and the2N® BRI Enterprise 2N® BRI Lite
same type of hardware and apply identical firmware and control (configuration)
software. The only difference lies in the count of BRI ISDN interfaces:
Interface
2N®BRI Lite 2N®BRI Enterprise
BRI ISDN 1 (NT/TE) 2 (1 TE ; 1 NT)
Ethernet YES* YES*
*The VoIP–SIP support depends on Part No. (subject to licence).
Telephone Cost Cuts
Having connected to your ISDN PBX, you can2N® BRI Enterprise / BRI Lite
make calls to the mobile network directly. This saves your PSTN – GSM
.connection costs
You do not pay for barred calls. You can set groups of barred numbers in the
gateway.
A flexible setting of the Least Cost Router helps you call GSM numbers at
.minimum operational costs
You can route calls to alternative providers' networks via the VoIP/SIP interface.
As all gateway user calls are added up for billing purposes, you are
advised to use the most advantageous tariff offered by your provider.
®
62N TELEKOMUNIKACE a.s., www.2n.cz
2N BRI Enterprise / 2N® BRI Lite Basic Features
®
Integration of the best features of two communication technologies: ISDN and
GSM
VoIP–SIP telephony support with G.711a/u and G.729ab codecs
1
Intelligent routing of incoming and outgoing calls
Web interface for gateway configuration and SMS sending/receiving
Automatic no answer SMS sending for GSM networks
Automatic missed call SMS in the GSM network
Simple recording of a welcome note, DISA voice message
Automatic recording of call data and detailed statistics (CDR)
ENBLOCK/OVERLAP ISDN dialling switch option
Monitoring of ISDN BRI line statuses and alarm SMS sending option
Automatic sending of Alive SMS in user–defined intervals
Easy firmware upgrade via a configuration program
External synchronising source connection option (BRI Enterprise)
Mobility Extension support.
2
[1]
Depending on the licence
[2]
Will be available in early 2013
DialThru (2N® BRI Enterprise)
The difference between and lies in the DialThru2N BRI Enterprise
®
2N BRI Lite
®
functionality. DialThru enables the gateway to be connected between the PBX and the
voice service provider line, i.e. PSTN. The GSM gateway in the DialThru mode routes,
based on the LCR, calls into the PSTN or GSM/UMTS networks.
Refer to the figure below for a schematic diagram of the connecti2N BRI Enterprise
®
on.
The gateway works as a dial–through router (using both the TE and NT ports in the
DialThru
®
72N TELEKOMUNIKACE a.s., www.2n.cz
mode) for calls to a mobile network, and a monitoring system, which, with the
appropriate licence, sends SMS to the provider (in the case of line unavailability, e.g.).
The GSM gateway contains just one ISDN BRI port and thus cannot2N BRI Lite
®
work in the DialThru mode. It can be connected to a PBX on a trunk line or extension
and route calls to the GSM/UMTS networks only – see the figure below.
®
82N TELEKOMUNIKACE a.s., www.2n.cz
1.2 Safety Precautions
It is prohibited to use any transmitters, including the GSM/UMTS gateways, in areas
where explosives are used, such as quarries.
It is prohibited to use the GSM gateways at petrol2N BRI Enterprise / BRI Lite
®
stations where mobile telephones are also prohibited.
GSM phones may affect sensitive life–saving devices in medical centres. Therefore, it is
forbidden to use GSM/UMTS devices, including the GSM gateways, in such facilities.
In general, any prohibition regarding mobile phones based on RF energy radiation
applies to GSM/UMTS devices too.
If necessary, the GSM gateways may be installed at a safe distance from the prohibited
area and connected with the original place through an Ethernet cable.
Although GSM gateways are not intended for cars or aeroplanes, all relevant
prohibitions and regulations regarding mobile phones apply to them too.
®
92N TELEKOMUNIKACE a.s., www.2n.cz
1.3 Upgrade
The manufacturer reserves the right to modify the product in order to improve its
qualities.
In response to the customers' requirements, the manufacturer constantly improves the
software contained in the product (firmware). For the latest 2N BRI Enterprise /
®
firmware version and the User Manual refer to the 2N .2N® BRI Lite web sites
Refer to the , , for a detailed description of the S. 2 Description and Installation 2N
®
firmware upgrade.BRI Enterprise / 2N® BRI Lite
Manual
Version
Changes
1.0
The User Manual relates to the 2N BRI Enterprise / BRI Lite
®
firmware version .1.5.0
®
102N TELEKOMUNIKACE a.s., www.2n.cz
1.4 Terms and Symbols Used
Manual Symbols
Safety
Always abide by this information to prevent persons from
injury.
Warning
Always abide by this information to prevent damage to the
device.
Caution
Important information for system functionality.
Tip
Useful information for quick and efficient functionality.
Note
Routines or advice for efficient use of the device.
Future Functions, Innovations
The in this document designates the functions that are undergrey-marked text
preparation or development at present.
®
112N TELEKOMUNIKACE a.s., www.2n.cz
2. Description and Installation
This section describes the product and its2N BRI Enterprise /®2N BRI Lite
®
installation.
Here is what you can find in this section:
2.1 Before You Start
2.2 Brief Installation Guide
2.3 Available ISDN BRI Extension Configurations
2.4 IP Voice Transmission
2.5 Types of 2N® BRI Enterprise Connection
®
122N TELEKOMUNIKACE a.s., www.2n.cz
2.1 Before You Start
Caution
Make sure that you are equipped with all system components
necessary for putting in operation2N® BRI Enterprise / Lite
(SIM card, ISDN phone and/or duly configured ISDN BRI line of
your PBX or PSTN, an available Ethernet/USB socket and a PC
for initial gateway configuration).
Product Completeness Check
Before installing this product, check whether the gateway delivery complies 2N BRI
®
with the following packing list:
Package BRI Lite BRI Enterprise
2N BRI Enterprise / Lite
®
1 1
Power supply adapter 1 1
Long antenna 1 – 2* 1 – 2*
Ethernet cable 1 1
BRI ISDN cable 1 2
Wall mounting set 1 1
*depends on the Part No.
Connector Lay–Out – Lower Side
The following connectors are available on the BRI gateway bottom:
Connector type BRI Lite BRI Enterprise
DC Jack 2.1mm supply connector YES YES
10/100BaseT Ethernet connector YES YES
ISDN BRI TE interface NO YES
ISDN BRI NT interface NO YES
ISDN BRI NT/TE interface YES NO
®
132N TELEKOMUNIKACE a.s., www.2n.cz
Caution
2N® has two RJ45 connectors, which, however, areBRI Lite
cross–connected into one ISDN BRI. Be sure to connect just one
ISDN BRI line to make the system work properly. Which of the
RJ45 connectors will be used depends on the type of the
equipment to be connected (NT/TE) and the interconnecting
cable (cross/straight).
Connector Lay–Out – Upper Side
There are SMA female antenna connectors to each GSM/UMTS module on the 2N BRI
®
upper side.Enterprise / Lite
Status LED Indicators – 2N® BRI Lite
The status is indicated by five LEDs on the front side. BRI 1 and BRI 22N BRI Lite
®
indicate the status of ISDN BRI B–channels and CH 1 and CH 2 indicate the status of
each GSM/UMTS module. Refer to the table below for the statuses
®
142N TELEKOMUNIKACE a.s., www.2n.cz
LED Indicators
Power
supply
green light – mains powered
– device switched offno light
GSM/UMTS
network
green light – call in progress
errorred light –
network registration, SMSgreen flashing –
module restartred flashing –
– signal intensity indicationRed/green flashing
ISDN port
green light – 2 calls in progress
– ISDN synchronisation/active callgreen flashing
– ISDN disconnectedred light
– synchronisation of lower ISDN layersred flashing
Ethernet
port
green light – disconnected+ no orange light
100BaseT connected, ingreen light + orange flashing –
operation
no green light + orange light – 10baseT connected, no operation
green flashing + orange flashing – 10BaseT connection, in
operation
Signal
intensity
Signal intensity indication:one segment = less than –109dbmtwo
segments = more than –95dbmthree segments = more than
–81dbmfour segments = more than –65dbm
*If the devices have been interconnected, the layers will not be connected until the
first call.
Status LED Indicators – 2N® BRI Enterprise
The status is indicated by five LEDs on the front side. BRI 1 and2N BRI Enterprise
®
BRI 2 indicate the status of ISDN BRIs and CH 1 and CH 2 indicate the status of each
GSM/UMTS module. Refer to the table below for the statuses.
®
152N TELEKOMUNIKACE a.s., www.2n.cz
LED Indicators
Power
supply
green light – mains powered
– device switched offno light
GSM/UMTS
network
green light – call in progress
errorred light –
network registration, SMSgreen flashing –
module restartred flashing –
– signal intensity indicationRed/green flashing
ISDN port
green light – 2 calls in progress
– ISDN synchronisation/active callgreen flashing
– ISDN disconnectedred light
– synchronisation of lower ISDN layersred flashing
Ethernet
port
green light – disconnected+ no orange light
100BaseT connected, ingreen light + orange flashing –
operation
no green light + orange light – 10baseT connected, no operation
green flashing + orange flashing – 10BaseT connection, in
operation
Signal
intensity
Signal intensity indication:one segment = less than –109dbmtwo
segments = more than –95dbmthree segments = more than
–81dbmfour segments = more than –65dbm
* If the devices have been interconnected, the layers will not be connected until the
first call.
**Remember to set the signal intensity indication in the gateway configuration menu.
Potential GSM/UMTS Troubles
All gateways work reliably under a long–time full load. The following2N GSM
®
problems may be caused by GSM/UMTS networks:
The GSM/UMTS module(s) cannot log in, log in slowly, or log out occasionally.
This problem may be caused by any of the following situations:
The GSM/UMTS signal is low. The minimum signal level should be
approximately . If lower, change the antenna position or type!–80dBm
The GSM/UMTS cell (BTS) to which the GSM/UMTS modules are trying to
log in is overloaded. Change the antenna position or reduce the count of
the logged–in GSM/UMTS modules.
One of the GSM/UMTS modules is permanently logged–out or fails to make
outgoing calls:
The problem indicates a GSM/UMTS network overload on the installation
site. To eliminate the problem, set the parameter to Relax delay 2
. If the GSM module fails to log in or rejects to make outgoingseconds
GSM calls even after the gateway restart, consult your GSM provider for
your SIM card/GSM module availability.
The manufacturer shall not be held liable for any SIM card or provider service
unavailability in the case of a breach of the provider's SIM terms and conditions for the
SIM card use.
®
162N TELEKOMUNIKACE a.s., www.2n.cz
2.2 Brief Installation Guide
Installation Conditions
The following installation conditions have to be met for a proper installation:
2N BRI Enterprise / BRI Lite® is to be installed on a site with enough free
space.
2N BRI Enterprise / BRI Lite® is to be mounted on a suitable vertical surface.
For this purpose, a hanger is included in the gateway delivery, which is fitted to
the wall using dowels and screws and used for gateway hanging.
It is possible to operate the gateway in another working position too, e.g. on a
desk, for a short time for servicing and testing purposes, for example.
Any excess of the allowed working temperature may not affect the 2N BRI
®
function immediately but may result in faster ageing andEnterprise / BRI Lite
lower reliability. For the allowed working temperature and humidity ranges refer
to .S. 7
2N BRI Enterprise / BRI Lite® is not designed for high–vibration
environments such as means of transport, machine rooms, and similar.
2N BRI Enterprise / BRI Lite® is not designed for dusty environments or
places exposed to high humidity and temperature changes.
2N BRI Enterprise / BRI Lite® may not be exposed to aggressive gases, acid
and solvent vapours (during cover cleaning, e.g.).
2N BRI Enterprise / BRI Lite® is intended for indoor use. It may not be
exposed to rain, flowing water, condensing moisture, fog, and so on.
2N BRI Enterprise / BRI Lite® may never be exposed to direct sunshine or
placed close to heat sources (radiators).
A sufficient clearance must be kept over and under 2N BRI Enterprise / BRI
®
for cabling and air flow to carry off the heat.Lite
A sufficient GSM/UMTS signal intensity has to be provided for 2N BRI
®
.Enterprise / BRI Lite
172N TELEKOMUNIKACE a.s., www.2n.cz
®
An adequate capacity of the GSM/UMTS network has to be ensured (no BTS
overload). Remember that multiple GSM gateways used in one location may
overload the base transceiver station (BTS) you are currently logged in to. This
may lead to a permanent or occasional rejection of GSM/UMTS calls!
No strong electromagnetic radiation is allowed on the 2N BRI Enterprise /
®
installation site.BRI Lite
No strong electromagnetic reflections are allowed on the 2N BRI Enterprise /
®
antenna installation site.BRI Lite
An inappropriate location of or its antenna2N BRI Enterprise / BRI Lite
®
close to television, broadcasting and/or other rf–sensitive sets may impair the
function of these sets.
Being a source of radio frequency emissions, the 2N BRI Enterprise / BRI
®
antenna should not occur in the close vicinity of the human body. The healthLite
hazard is higher than with mobile phones as, generally, gateways shared by
multiple users show a very high traffic.
It is recommended that the power supply adapter should be connected to a
network with a UPS back–up and due overvoltage protection.
SIM Card Inserting/Removing
Insert the SIM card in the bottom as shown in the2N BRI Enterprise / BRI Lite
®
figure. As the SIM slots are of the Push/Pull type, just slide the card in and push it into
position. Push the SIM gently to slide it out of the slot.
®
182N TELEKOMUNIKACE a.s., www.2n.cz
Caution
Be sure to such provider/SIM card services as callset
forwarding, call barring, preferred networks, SMS centre, etc. in
your mobile phone into before inserting the SIM card 2N
®
. BRI Enterprise / BRI Lite
If two SIM cards are used, make sure that both the SIM cards
have or .one and the same PIN PIN code request disable
Having inserted the SIM card, restart 2N BRI Enterprise
®
to make the SIM card log in./ BRI Lite
Remember to the service beforedisable Another call on line
using the SIM cards!
Antenna Connection
2N BRI Enterprise / BRI Lite® is equipped with a SMA female antenna connector for
all the GSM/UMTS modules. The external antenna should always be installed vertically
on a site with a good wireless signal.
Warning
Tighten the antenna connector gently with your hand – never
!use a wrench
Being a source of radio frequency emissions, the 2N BRI
®
antenna should not be very close to theEnterprise / BRI Lite
human body. The is higher than with mobilehealth hazard
phones as, in general, gateways shared by multiple users show
a very high traffic.
®
192N TELEKOMUNIKACE a.s., www.2n.cz
Note
The antenna has a sufficient gain for a trouble–free operation
under normal conditions. If the signal is poor or you want to
place your antenna away from 2N BRI Enterprise / BRI Lite
®
, you can use an antenna with an SMA–connector terminated
cable. The antenna should be mounted vertically.
Refer to , , for the antenna S.7 Technical Parameters
parameters.
Power Supply Connection
Use only the power supply adapter included in the delivery. Make sure that the electric
distribution network voltage is in compliance with the data on the supply adapter plate
before plugging the adapter and that the antenna is connected properly. If you connect
the power supply without having connected the antenna, the GSM module transmitter
may get damaged. Plug the supply adapter into the mains socket and only then
connect the adapter connector to the gateway. Refer to the status indicators.
Warning
Connecting a defective or inappropriate power supply adapter
may lead to a temporary or permanent 2N BRI Enterprise /
®
error!BRI Lite
Check whether the antenna is connected before plugging the
adapter. Feeding the device without antenna connection
may result in the GSM module transmitter damage.
®
202N TELEKOMUNIKACE a.s., www.2n.cz
Ethernet Cable Connection
To connect into the Ethernet network, use a standard2N BRI Enterprise/Lite
®
straight cable terminated with RJ–45 connectors (included in the package). The GSM
gateway supports the 10BaseT and 100BaseT standards, the Ethernet connection
status is indicated by the status LED indicators located on the RJ–45 connector (refer
to for details). S. 2.1
Caution
The Ethernet interface is used for remote supervision and
configuration only, i.e. does not contain the VoIP interface.
With a proper licence, the device provides the VoIP–SIP support.
RJ–45 LAN Connector
NT and TE Connectors
1 not used2 not used3 Tx4 Rx5 Rx6 Tx7 not used8 not usedISDN devices are
connected to the NT/TE connectors depending on the configuration of your
telecommunications equipment. They are connected via a 4–wire passive bus with the
aid of RJ–45 connectors. Refer to the figure below for the NT/TE connector pin lay–out.
®
212N TELEKOMUNIKACE a.s., www.2n.cz
TE connector The figure below shows connected as2N BRI Enterprise / BRI Lite
®
network termination (NT) – extension for your ISDN PBX or ISDN phone, i.e. your own
equipment.
The figure below shows connected as terminal2N BRI Enterprise / BRI Lite
®
equipment (TE) – extension from the ISDN (PSTN), i.e. from your service provider.
An example of the connection in the ISDN mode follows. 2N BRI Enterprise
®
®
222N TELEKOMUNIKACE a.s., www.2n.cz
Caution
2N BRI Lite® is equipped with just one ISDN BRI. Hence, two
independent devices cannot be connected at the same time!
®
232N TELEKOMUNIKACE a.s., www.2n.cz
2.3 Available ISDN BRI Extension Configurations
You have to know the way of connection of your ISDN devices in order to configure
your GSM gateway correctly. For information on your2N BRI Enterprise / BRI Lite
®
ISDN type, check your ISDN extension provider's registration form or contact your
telephone network administrator.
Point–to–Point Configuration
The Point–to–Point (EuroISDN with DDI) configuration interconnects directly one ISDN
terminal (TE) and a network terminal (NT) (see the figure below). This type is applied
mainly where PBXs are connected to the ISDN.
Point–to–Multipoint Configuration
Point–to–Multipoint (EuroISDN with MSN) is another type of ISDN terminal
interconnection. Here the network terminal (NT) is interconnected with up to eight
ISDN terminals through a 4–wire passive bus as shown in the figure below.
®
242N TELEKOMUNIKACE a.s., www.2n.cz
2.4 IP Voice Transmission
Speech Encoding Methods
Voice transmission is strictly separated from signalling in VoIP networks. Modern VoIP
networks mostly use the RTP (Realtime Transport Protocol) for voice transmission. The
purpose of the RTP is only to transmit data (voice) from a source to a destination at
real time. Codecs are used to save the channel data capacity. Codecs process the voice
signal using variable algorithms to minimise the volume of user data. The degree of
compression used by the codec affects the quality of voice transmission. Thus, the
better voice transmission is required, the wider data range (the higher transmission
rate) is needed. The MOS (Mean Opinion Score) scale is used for rating voice
transmission quality, where 1 means the worst and 5 the best quality. For a survey of
the codecs supported by gateway refer to the table below.2N BRI
®
Codecs supported
Standard Algorithm
Transmission rate
[kbps]
MOS
G.711a PCM 64 4.1
G.711u PCM 64 4.1
G.729 is an optional part of the
system.
CS–ACELP 8 3.92
For gateway, quadruple the above mentioned rates (two fully duplex calls) 2N BRI
®
and add the TCP and IP header transmission rate to the result to get the resultant
transmission rate.
It is important to keep both a stable appropriate transmission rate during connection
and a small and identical transmission time per data packet in order to maintain a
high–quality voice transmission.
G.711 – this codec is used in digital telephone networks. The PCM (Pulse Code
Modulation) is used for voice signal encoding. The sampled signal is encoded in
12 bits and then compressed using a non–linear scheme into the resultant 8 bits.
Europe uses the A–law compression system while North America and Japan obey
the µ–law. The resultant data flow is 64 kbps.
G.729 – this codec uses the CS–ACELP (Conjugate–Structure
Algebraic–Code–Excited Linear–Prediction) algorithm with the resultant
transmission rate of 8 kbps. The speech signal is split into blocks of 10 ms each.
The parameters of these blocks are then inserted in frames of the size of 10
bytes. 2–byte frames are generated for noise transmission.
During call set–up, a codec is selected automatically for voice transmission. g2N BRI
®
ateway supports the codecs included in the table above. The type of codec to be used
depends on your VoIP network (individual devices) and your gateway2N BRI
®
configuration. gateway is designed primarily for VoIP corporate networks and2N BRI
®
tries to meet the opponent's codec requirements. If a codec is requested that is
incompatible with , the call will be rejected.2N BRI Enterprise
®
The SIP and ITU–T H.323 recommended protocols are mostly used for connection
establishing, maintaining and cancelling. gateway uses the (Session2N BRI
®
SIP
Initiation Protocol) signalling.
®
252N TELEKOMUNIKACE a.s., www.2n.cz
Tip
In the case of separated direct connection of your SIP Proxy and
, use the G.711 codec to achieve a high2N VoiceBlue Next
®
voice quality.
SIP Components
The following components are involved in the SIP message exchange:
UAC (User Agent Client) – the terminal device client, which initiates SIP
signalling.
UAS (User Agent Server) – the terminal device server, which responds to SIP
signalling from the UAC.
UA (User Agent) – a SIP network terminal (SIP phones, gateways to other
networks, etc.), which contains the UAC and UAS.
Proxy server – receives connection requests from the UA and transfers them to
the next Proxy server if the given station is not under it administration.
Redirect server – receives connection requests, but, instead of sending them to
the called line, sends them back to the requesting device asking for where to
route the request.
Location server – receives registration requests from the UA and updates the
terminal database accordingly.
All the server components (Proxy, Redirect, Location) are mostly on one physical
device called Proxy server, which is responsible for keeping a client database and
connection establishing, maintaining and terminating, as well as call routing.
The gateway VoIP–GSM gateway acts as a UA in any case (has the same2N BRI
®
functions as a VoIP phone), i.e. receives call set–up requirements and, on the basis of
its inner LCR table, routes calls to GSM networks.
None of the SIP–defined server components are integrated in the gateway2N BRI
®
gateway.
SIP Signalling Messages
Below is a list of messages sent via the SIP:
INVITE – connection set–up request;
ACK – INVITE confirmation by the final message addressee;
BYE – connection termination;
CANCEL – failed connection cancellation;
REGISTER – UA registration with the SIP Proxy;
OPTIONS – server capability query.
The answers to the SIP messages are numerically coded as the case is with the http
protocol. Below are the most important ones:
1XX – information messages (100 – trying, 180 – ringing, 183 – progress);
2XX – successful request completion (200 – OK);
3XX – request forwarding needed (302 – temporarily moved, 305 – use Proxy);
4XX – error (403 – forbidden, 486 – busy here);
5XX – server error (500 – Server Internal Error, 501 – not implemented);
6XX – global failure (606 – not acceptable).
®
262N TELEKOMUNIKACE a.s., www.2n.cz
®
272N TELEKOMUNIKACE a.s., www.2n.cz
2.5 Types of 2N® BRI Enterprise Connection
This subsection deals with the types of connection of the gatewa2N BRI Enterprise
®
y to the main ISDN BRI extension.
ISDN TE – 2N BRI Enterprise Connection
®
The connection type shown in the figure below provides communication via a
GSM/UMTS gateway without PSTN connection. The ISDN telephone sets are connected
to the NT port of the GSM gateway, while a mains adapter simulating power supply
from the PSTN is connected to the TE port. The adapter is available under Part No.
5020002.
2N BRI Enterprise Point–to–Point Connection
®
This type of connection is especially suitable for direct calls from an ISDN branch
network to a GSM/UMTS network.
Another possible connection type is NT, where gateway synchronisation is derived from
the PSTN BRI extension.
®
282N TELEKOMUNIKACE a.s., www.2n.cz
With multiple GSM gateways, the connection lay–out is as follows:
2N BRI Enterprise Connection as DialThru Router
®
This type of connection saves one BRI port to the PBX. Incoming PSTN calls are treated
by the GSM/UMTS gateway in the DialThru mode while outgoing calls are routed
according to the LCR table.
The figure below shows the gateway as a DialThru router for the Point–to–Multipoint
extension. Calls are routed automatically into GSM, UMTS or ISDN based on the
internal LCR rules.
®
292N TELEKOMUNIKACE a.s., www.2n.cz
®
302N TELEKOMUNIKACE a.s., www.2n.cz
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