MGCP Call Preservation

MGCP gateway is a Survivable endpoint unlike H323 which is not survivable. What does it mean? It means that an active call through an MGCP gateway will not tear-down and the call will be preserved. As discussed already in another section that an MGCP gateway terminates Layer 2 signalling at the gateway while Backhauling LayerContinue reading “MGCP Call Preservation”

MGCP Gateway Setup

MGCP Configuration Using Trombone Feature: To register an MGCP gateway to call manager, follow these steps: Do a show inventory OR show diag to check the position of E1/T1 Enable the E1/T1 by using command – card type T1 0 0 OR card type T1 0 1 (whatever the case may be) Do show verContinue reading “MGCP Gateway Setup”


In a typical ISDN setup for an Inbound call from PSTN to an IP phone (-SCAC-) CCM  –  GW  – PSTN Setup <——- Call proceeding ——-> Alerting ——-> Connect ——> Gateway and PSTN switch exchange Q921 Layer 2 information. Gateway registers with ISDN switch and terminates Q921 at gateway. A Q931 Setup message arrives. TheContinue reading “MGCP Call Flow – ISDN PRI”

MGCP – How it works?

General: MGCP stands for Media Gateway Control Protocol. It’s a client-server protocol which means that it has  to depend on Media Controller (Call agent) for call routing. In case of Cisco this MC is a CUCM. The Call agent controls the ports of a MGCP gateway. UDP Port 2427  is used for communication between CallContinue reading “MGCP – How it works?”