Nortel Meridian PBX and Cisco CallManager Integration

Introduction

This configuration is taken from a Nortel Meridian 1 Option 81c private branch exchange (PBX), which runs Release 2337. A T1 Primary Rate Interface (PRI) was defined to connect a DT24+ Voice over IP/Time Division Multiplexing (VoIP/TDM) gateway.

A NT-6D80AB 4 port Multiple Serial Data Link (MSDL) was used to provide D-channel framing for the PRI. There are three generations of PRI cards:

• The oldest generation supports one PRI and requires one serial port on the MSDL for the D-channel.

• The next generation supports 2 PRIs and requires two serial ports on the MSDL for the D-channel.

• The newest generation supports one PRI and does not require an MSDL serial port for the D-channel. (It has a high-level data link (HDLC) framer on the card.)

This PBX had the second generation PRI card; it required a physical cable to be run from the PRI card to a port on the MSDL.

The DT24+ was set to the ISDN Network side with a switch type of 5E8 Custom. The PBX PRI trunk was set to the ISDN User side with a switch type set to ESS5. This worked and is the configuration shown. We tried to set the switch type on the PBX trunk to DMS100, but no matter what we did on DT24+, the PBX always saw the trunk as in maintenance mode, and the calls were rejected.

For the D channel to become active, it does not matter which side (PBX or the VoIP gateway) is set to ISDN USER or NETWORK. Set one device to ISDN USER and the other to NETWORK.

At this point, Layer 1 is active. For Layer 2 to initialize, each side sends Q.921 SABME frames. One side responds with a Q.921 UA Unacknowledged message. After this, both sides begin to exchange Receiver Ready (RR) messages. At this point, Layer 2 connectivity is established.

For further explanation of the PBX commands, refer to Nortel's "Administration Input/Output Guide for Meridian 1" and Nortel's "1.5 mb DT1/PRI Administration and Maintenance Guide."

Prerequisites

Requirements

There are no specific requirements for this document.

Configure

In this section, you are presented with the information to configure the features described in this document.

This trunk was configured for a test scenario. The extension for the IP phone was x7373 and for the digital phone was x6925. When you called the IP phone from the digital phone, the access code 8815 was first dialed to choose the specific PRI trunk (see ACOD 8815 in LD21), and then the extension of the IP phone was dialed. For this test, the configuration allowed a number to be chosen for the IP phone that can be uniquely routed.

Note: Use the Command Lookup Tool (registered customers only) to obtain more information on the commands used in this section.

Configurations

This document uses these configurations:

Troubleshoot

Refer to T1 PRI Troubleshooting for tips to debug PRI trunks.

Note: If you receive an intermittent fast busy signal when you call from an IP phone to a Nortel phone, make sure that you use the R2 analog signaling.

Troubleshooting Commands

The Output Interpreter Tool (registered customers only) (OIT) supports certain show commands. Use the OIT to view an analysis of show command output.

Note: Refer to Important Information on Debug Commands before you use debug commands.

If you experience any problems after the Tspan is connected, and there are no framing, LOS, or sync errors, refer to these documents for ideas:

• T1 Layer 1 Troubleshooting

• T1 Error Events Troubleshooting

• T1 Alarm Troubleshooting

Related Information

• Technical Support & Documentation - Cisco Systems