Overview
The Integrated Services Digital Network (ISDN) evolves from the Integrated Digital Network (IDN), provides end-to-end digital connections, and supports a wide range of services, including voice, high-speed fax, video phone, intelligent telegraph, and teletext services.
A BRI interface is an ISDN interface, and supports two data channels and one signaling channel. The data channel (channel B) with the bandwidth of 64 kbit/s can carry voice or data services, and the signaling channel (channel D) with the bandwidth of 16 kbit/s transmits signaling of the ISDN. That is, the bandwidth of a BRI interface is 144 kbit/s (sum of bandwidths of two data channels and one signaling channel).
A BRA trunk is a digital circuit trunk that supports calls over a maximum of two channels. A BRA trunk group implements voice communication between PBX users and inter-office users.
Precautions
The AR uses a 2BST card to connect to a Cisco device through the RJ45 interface, and needs to be configured to work in NT mode.
The voice functions are controlled by the license. By default, voice functions are disabled on a newly purchased device. To use the voice functions, apply for and purchase the license.
In this example, the commands on the Cisco router are recommended ones. The product version is Cisco IOS Software, C2900 Software (C2900-UNIVERSALK9-M), Version 15.1(4)M1, RELEASE SOFTWARE (fc1). For details, visit http://www.cisco.com/techsupport.
Networking Requirements
In Figure Connecting RouterA and RouterB through a BRA trunk, RouterA (AR device) and RouterB (Cisco device) are gateways of two branches, respectively. RouterA used as a PBX connects to IP phones and analog phones. Enterprise branch A connects to the ISDN through a BRA trunk, and connects to enterprise branch B over the ISDN.
Figure1 Connecting RouterA and RouterB through a BRA trunk
The requirements are as follows:
Users of RouterA can call users of RouterB.
Users of RouterB can call users of RouterA.
Users of RouterA can call each other.
Data Plan
The data plan here is used for reference. The actual configuration depends on the actual situation.
User Name | Access Terminal | Number |
User A | Analog phone | 6201 |
User B | IP phone | 6202 |
User C | Analog phone | 9001 |
Device | Type | Name |
RouterA | Outgoing prefix | 9 |
RouterA | Intra-office prefix | 62 |
RouterB | Dialup peer (POTS) | 9001 |
RouterB | Dialup peer (POTS) | 62 |
