CUCM set up MGCP Gateway

This page outlines the process one would take to add an IOS gateway running MGCP to their Cisco Unified CallManager (CUCM) cluster.

## Introduction

MGCP is a client/server protocol that allows the call agent (CA) to take control of a specific gateway endpoint (port). MGCP has the advantage of centralized gateway administration in the CUCM. CUCM controls the state of each port on the gateway endpoint .MGCP gateway can be controlled on a per endpoint (TDM port) level but H.323 and SIP cannot

An MGCP gateway is completely controlled by the CUCM, thus configurations must be done on the CUCM. another point to consider when designing or planning your system is that if your gateway loses ip connection to the CUCM it may fall into SRST fallback and it must have dial-peers configured to route telephony traffic until the connection to the CUCM is restored.

## MGCP Gateway Support

MGCP support in CUCM includes a wide range of analog and digital interfaces that can be used ton several Cisco router and switch platforms. FXO, FXS, T1-CAS, T1-PRI, E1-CAS, E1-PRI but some voice ports are not supported by MGCP say, E&M voice ports. CUCM pushes the Cisco IOS MGCP gateway configuration from the Cisco TFTP server to the gateway when automatic configuration is configured.

CUCM also supports Q.931 backhaul. Q.931 backhaul is only supported on ISDN voice ports. MGCP backhaul allows CUCM to process the Q.931 messaging from the ISDN circuit. The gateway router encapsulates the Q.931 signaling from the gateway over TCP port 2727

### Q.931 Backhaul

Q.931 backhaul is a reliable TCP transport layer TCP/IP connection between CUCM and Cisco MGCP gateway. Q.931 backhaul is an encapsulation of the Q.931 signaling in the D channel of the ISDN TDM interface. Q.931 backhaul carries the raw Q.931 signaling to CUCM to be processed natively. The Gateway is still responsible for the termination of the Layer 2 Q.921 Link Access Protocol D-Channel (LAPD) signaling, but all ISDN layer 3 call setup/call tear down signaling (Q.931) is sent to CUCM for processing.

## CallManager Side

Step 1: from the CUCM main screen go to **Device > Gateway**.

Step 2: Click the **Add New** button.

Step 3: Choose the Appropriate gateway or router type.

you can find this information in using the **show version** command.

Step 4: Click **Next.**

Step 5: Choose **MGCP** from the protocol drop-down menu and click Next

### This will open a new page

Step 1: Enter the hostname or fully qualified domain name (FQDN) of the gateway in the Domain name field. If a domain name is specified in the Cisco router you must provision an FQDN. If the FQDN specified in the CUCM does not match the “hostname” dot “domain name” of the Cisco IOS router, then end pint will never register.

This is the combination of the gateways 'hostname' and 'ip domain-name'.  if this doesn't match then the gateways registration will be rejected.

1a. to set these values use the following

* commandsGW1# config t
* GW1(config)# hostname Buffalo-RTR
* Gateway1(config)#ip domain-name MonroeSHouse.lcl
* Gateway1(config)# end
* Gateway1#copy run start

Step 2: Enter a meaningful description of the gateway.

Step 3: Select the appropriate CUCM group

Step 4: Configure the ISDN switch type (you may need to get this information from your provider)

Step 5: Locate the configured slots, VICS and endpoint selection, and select the voice hardware module placed in the slot. you will have to select the card for Slot 0 and click the save button before you can select the cards installed in the Voice Gateway.

Step 5a: you can verify the cards installed in your voice gateway with the **show inventory** command

Step 5b: you can use the PID information from the **show inventory** to verify you are selecting the correct cards in the subunits.

step 5c: once you have all of your cards selected on the screen you should need ports next to them to configure.

Step 6: Click **Save**. Reset the gateway ( or click Apply config) for the changes to apply.

### Add MGCP endpoints

Endpoints are added by selecting the Voice modules and voice interface cards at the Gateway configuration page. To add endpoints to a gateway, follow these steps:

Step 1: Locate the configured slots, VICs and Endpoints selection and select the voice hardware module placed in the slot.

Step 2: The subunits (VIC slots) of the selected voice module will display. Select the subunit (voice interface card)

Step 3: Click Save.

Step 4: Repeat the process to indicate all the voice interface cards on the gateway.

### Configure MGCP endpoints

Step 1: Click the endpoint identifier (0/0/0)

Step 2: Select the device protocol or signaling for the endpoint. T1 and E1 interfaces support channel associated signaling (CAS) or common channel signaling (CCS) if the interface is an ISDN Primary Rate Interface (PRI). Analog interface supports ground-start (GS) and loop-start (LS) signaling. Select the signaling mechanism that is used on the endpoint and click Next.

Step 3: Enter a description for the point.

Step 4: Select the device pool for the endpoint.

Step 5: Choose the Calling Search Space (CSS) and Significant digits under the Inbound Call routing section.

Step 6: Configure the interface information for the T1 line \*Note\* This information must match on both ends of the connection for this connection to function properly.

Step 7: you will have to fill out the information in the Call routing information - incoming calls

Step 7a: depending on your dial plan you will have to select the adequate number of significant digits

Step 7b: Select the correct calling search space for calls

Step 7c: if you are utilizing AAR on your CUCM select the appropriate Calling search space

step 7d: depending on your dial plan you may have to add a prefix DN to your number.

Step 8: configure the Product specific configuration Layout information. this info must also match on both sides for your connection to function

Step 9: Click Save. Click Reset to rest the gateway. The reset functionality will push configuration changes to the gateway.

## Gateway Side

This section assumes that your gateway has no previous configurations applied.

Step 1: Configure hostname (this must match exactly to what is in CUCM or the two will not synchronize)

Step 2: Configure domain-name (this must match exactly to what is in CUCM or the two will not synchronize)

Step 3: Configure CCM Manager Settings

* ccm-manager mgcp
* ccm-manager config server "**ip of the cucm tftp / publisher server" "i**p of another cucm server**" "**ip of another cucm server**"**
* mgcp call-agent "***ip of the cucm server***" serivce-type mgcp
* example: mgcp call-agent 10.10.1.1 service-type mgcp

step 4(optional) if you are using a DNS environment you may have to add the ip of the DNS server to the voice gateway config using the command "ip name-server ***ip of the dns server***"

* example: ip name-server 10.10.1.4

## Verification

after you have everything configured you can check to see if the Gateway has registered to the CUCM using the CUCM interface and ios console.

#### Call manager Side

Go to Device > Gateway and click on see endpoints

if the connection is up the status should show "Registered to ***call manager hostname***"

#### Gateway side

* use the command show CCM-manager host

* use the command show ccm-manager config-download

* use the command show mgcp endpoints