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When you are using the Configuration Server feature, the gateway- and interface-specific
MGCP configuration commands are provided by CUCM in the form of an Extensible
Markup Language (XML) configuration file that is downloaded by the Cisco IOS gateway
from the CUCM TFTP server. This is the recommended approach to integrate Cisco IOS
MGCP gateways with CUCM. The Cisco IOS gateway dynamically loads the necessary
MGCP configuration commands from the XML file downloaded from the TFTP server.
When changes are made to the configuration in the CUCM database, a message is sent by
CUCM to the MGCP gateway instructing the gateway devices to download the updated
XML configuration file. Each device has an XML parser that interprets the XML file
according to its device-specific requirements. Cisco MGCP gateways, for example,
translate the content of the XML file into specific Cisco IOS commands for local execution.
Table 10-3 MGCP Digital Features
Gateway BRI*
*Cisco IOS 12.4(2)T supports BRI MGCP with the following hardware: NM-HDV2, NM-HD-XX, and on-board HWIC
slots. BRI MGCP is also supported on older Cisco IOS releases with NM-1V/2V hardware.
TI CAS
(E&M) T1 PRI T1 QSIG E1 PRI E1 QSIG
Cisco 3800 12.4(2)T Yes†
†AIM-VOICE-30 modules require Cisco IOS Release 12.2.13T.
Yes† Yes† Yes† Yes†
Cisco 2800 12.4(2)T Yes† Yes† Yes† Yes† Yes†
Cisco 3700 12.4(2)T Yes† Yes† Yes† Yes† Yes†
Cisco 3640 and 3660 12.4(2)T Yes† Yes† Yes† Yes† Yes†
Cisco 2600 and 2600XM 12.4(2)T Yes† Yes† Yes† Yes† Yes†
VG200 No Yes Yes Yes Yes Yes
Cisco 1751 and 1760 12.3(14)T Yes Yes Yes Yes Yes
WS-X4604-GWY Module No Yes Yes Yes Yes Yes
Communication Media
Module (CMM) 6T1/E1
N/A Yes Yes Yes Yes Yes
WS-X6608-T1/E1 N/A Yes Yes Yes Yes Yes
MGCP Configuration Server 237
Figure 10-3 illustrates the configuration and communication on and between CUCM and
the MGCP gateway. Notice that the router requires only two configuration commands:
ccm-manager config and ccm-manager config server ip-address.
Figure 10-3 MGCP Configuration Server Communication
Q.931 Backhaul
A distinguishing characteristic of ISDN interfaces is the common channel signaling (Q.931)
carried in the D channel (channel 24 in PRI interfaces and channel 17 in E1 interfaces). The
gateway does not process or change this signaling data; it just passes it to CUCM through
what Cisco calls the Q.931 backhaul channel. The gateway is still responsible for the
termination of the Layer 2 signaling (Q.921 link access procedure over the D channel
[LAP-D]). The gateway will not bring up the D channel unless it can communicate with
CUCM to backhaul the Q.931 messages contained in the D channel.
A Q.931 backhaul channel is a logical TCP connection between CUCM and Cisco MGCP
gateways. Q.931 backhaul forwards the Q.931 signaling traffic from an ISDN interface on
a gateway over TCP port 2727 to a CUCM configured as an MGCP call agent.
MGCP Gateway Configuration: CUCM
MGCP gateway implementation includes configuration steps on both the CUCM (MGCP
call agent) and the MGCP gateway that will be controlled.
V T1/E1 VWIC
MGCP Gateway
CUCM
1/1/1
TFTP
Download
10.1.1.101
10.1.1.1
Gateway Pulls
Configuration File
and Applies MGCP
Configuration
Administrator Configures
MGCP Gateway in
CUCM
CUCM Creates File
with MGCP Configuration
for Gateway
File is Stored on Cisco
TFTP Server
Gateway Configured to Use Configuration Server:
GW(config)#ccm-manager config server 10.1.1.1
GW(config)#ccm-manager config
PSTN
238 Chapter 10: Configuring Voice Gateways
The CUCM configuration steps for implementing an MGCP gateway are as follows:
Step 1 Add the MGCP gateway to CUCM.
Step 2 Configure the MGCP gateway in CUCM.
Step 3 Add one or more modules to the slots of the MGCP gateway in CUCM.
Step 4 Add voice interface cards, voice WAN interface cards, or high-density
voice WAN interface cards to the configured modules.
Step 5 Configure the MGCP endpoints (one or more per voice interface card).
Follow these detailed configuration steps to add an MGCP gateway to CUCM:
Step 1 From CUCM Administration, choose Device > Gateway.
Step 2 Click the Add New button. The Add a New Gateway window will open.
Step 3 From the Gateway Type drop-down list, choose the appropriate MGCP
gateway, as shown in Figure 10-4.
Step 4 Click Next.
Step 5 Choose MGCP from the Protocol drop-down menu and click Next.
Figure 10-4 displays the choosing of the Cisco 2811 router for an MGCP gateway
configuration.
Figure 10-4 MGCP Gateway Configuration
MGCP Configuration Server 239
Figure 10-5 displays the selection of the MGCP protocol for the gateway configuration.
Figure 10-5 MGCP Gateway Protocol Selection
The configuration of an MGCP gateway depends on the selected platform. In Figure 10-4,
a Cisco IOS 2811 router model has been selected.
The configuration of the MGCP gateway includes the following steps:
Step 1 Enter the hostname or fully qualified domain name of the gateway in the
Domain Name field. The name has to match the hostname or the hostname
and domain name (fully qualified domain name) of the Cisco IOS router.
Step 2 Enter a description for the gateway.
Step 3 Select a CUCM group.
Step 4 Configure the IDSN switch type.
Step 5 Click Save. Reset the gateway for the configuration changes to apply.
NOTE Some gateways support SCCP and MGCP, whereas few support only SCCP. The
Protocol list box appears when adding a gateway that has support for both of these
protocols. SCCP supports some features on analog FXS interfaces that are not available
from MGCP-controlled FXS ports.
NOTE The ISDN switch type is configured globally in Cisco IOS routers. The ISDN
switch type can also be set to a different value per ISDN interface. An interface command
will always override the inheritance of a global command. The global ISDN switch type
is also part of the gateway configuration in CUCM Administration. You can configure an
interface-specific switch type at the MGCP endpoint level in CUCM Administration.
To display help for the configuration parameters, click ? on the page, or from the Help
menu choose the For This Page option.
240 Chapter 10: Configuring Voice Gateways
Figure 10-6 displays the MGCP Gateway Configuration page.
Figure 10-6 MGCP Gateway Configuration
Endpoints are added by selecting 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 section, and select the
voice hardware module placed in the slot.
Step 2 Click Save. The subunits (voice interface cards slots) of the selected
voice module will display.
Step 3 For each subunit (voice interface cards slot), select the subunit.
NOTE Only voice modules have to be specified. If data network modules are used in a
slot, you do not have to select them.
Configure global parameters Get help for global parameters
Select Cisco Unified
Communications Manager Group
Enter gateway name Enter description
MGCP Configuration Server 241
Step 4 Click Save. The endpoints of the selected voice interface card will
display.
Step 5 Repeat Steps 4 to 5 for each subunit of a module. Repeat Steps 2 to 5 for
each module of the gateway.
Figure 10-7 shows the voice module and voice interface card (VIC) selection process.
Figure 10-7 MGCP Configuration
After adding voice modules and VICs in the Configured Slots, VICs, and Endpoints section
of the gateway, the configuration endpoints of the VICs are displayed.
To configure an MGCP endpoint, follow these steps:
Step 1 Click the endpoint identifier (for example, 0/3/0).
NOTE Use the Cisco IOS command show diag on the gateway to display the modules
and interface cards that the gateway is equipped with.
MGCP endpoint(s) are shown and can be clicked for endpoint configuration
Select VIC (per module)
242 Chapter 10: Configuring Voice Gateways
Step 2 Select the device protocol or signaling for the endpoint. T1 and E1
interfaces support channel associated signaling (CAS) or command
channel signaling (CCS) via ISDN PRI. Analog interfaces support
ground-start and loop-start signaling. Select the protocol that should
be used on the endpoint and click Next.
Step 3 Enter a description for the endpoint.
Step 4 Select the device pool that should be used by this endpoint.
Step 5 You can display help for any configuration parameters via Help > For
This Page.
Step 6 Click Save. Reset the gateway for configuration changes to be committed
to the gateway.
Figures 10-8 and 10-9 show an example of an MGCP E1 endpoint configuration.
MGCP Gateway Configuration: Cisco IOS Configuration
Two commands are required for a Cisco IOS MGCP gateway to pull its MGCP
configuration from the CUCM TFTP server.
The command ccm-manager config server ip-address specifies the IP address of the TFTP
configuration server. If more than one CUCM TFTP server is deployed in the cluster, a list
of IP addresses can be specified using a space between each IP address. The Cisco IOS
MGCP gateway prioritizes the IP addresses from left to right.
The command ccm-manager config enables the Configuration Server feature. The ccmmanager
config server command is ignored without this command.
For the Configuration feature to work, the following prerequisites must be met:
■ The MGCP gateway and the CUCM TFTP server have IP connectivity.
■ The MGCP gateway and endpoints are configured in CUCM.
■ The hostname or fully qualified domain name (FQDN) of the Cisco IOS MGCP
gateway has to match the CUCM MGCP gateway configuration.
If all these conditions are met and the gateway is configured with the ccm-manager config
and the ccm-manager config server commands, the gateway can download its XML
configuration file from the TFTP server.
The gateway then parses the XML file, converts the information to appropriate Cisco IOS
configuration commands, and configures itself for MGCP operation.
MGCP Configuration Server 243
Figure 10-8 MGCP E1 Endpoint Configuration
Figure 10-9 MGCP E1 Endpoint Configuration (continued)
Verify product-specific configuration and change if required
Click for help about configuration parameters
244 Chapter 10: Configuring Voice Gateways
The gateway registers with CUCM using the MGCP protocol.
After a successful configuration download, the MGCP gateway saves the running configuration
to NVRAM, which updates the startup configuration. Any manually added
configuration parameters are also saved to NVRAM if they were not previously saved.
Manually added configuration parameters are updates to the configuration that were made
using the command-line interface (CLI).
In Example 10-1, there is one CUCM TFTP server with an IP address of 10.1.1.1. There
is a Cisco IOS MGCP gateway with a connection to the PSTN using an E1 interface
(port 0/3/0). The gateway and its E1 PRI endpoint have been added to CUCM. At the
gateway, the commands ccm-manager config server 10.1.1.1 and ccm-manager config
server have been entered. No MGCP configuration commands have been manually
entered. The MGCP configuration is automatically downloaded and applied by the
Configuration Server feature.
After the gateway downloads the cnf.xml configuration file from the CUCM TFTP server,
the following MGCP commands are added to the router.
Example 10-1 Configuring MGCP Gateway Registration
controller E1 0/3/0
framing crc4
linecode hdb3
pri-group timeslots 1-31 service mgcp
!
interface Serial0/3/0:15
isdn switch-type primary-4ess
isdn incoming-voice voice
isdn bind-l3 ccm-manager
!
ccm-manager mgcp
ccm-manager music-on-hold
!
mgcp
mgcp call-agent 10.1.1.1 2427 service-type mgcp version 0.1
mgcp rtp unreachable timeout 1000 action notify
mgcp modem passthrough voip mode nse
mgcp package-capability rtp-package
mgcp package-capability sst-package
mgcp package-capability pre-package
no mgcp package-capability res-package
no mgcp package-capability fxr-package
no mgcp timer receive-rtcp
mgcp sdp simple
mgcp rtp payload-type g726r16 static
MGCP Configuration Server 245
MGCP Gateway: Registration Verification
MGCP gateways register with CUCM in a manner similar to SCCP phones. Each endpoint
in the CUCM MGCP gateway configuration can be verified to obtain the registration status.
Similar registration verification information is available from the gateway router via Cisco
IOS commands. The show ccm-manager command in Example 10-2 shows that the MGCP
gateway has a CUCM group that includes only one CUCM and that the gateway is currently
registered. There are some useful statistics, too.
Example 10-2 Verifying MGCP Gateway Registration
Router# show ccm-manager
MGCP Domain Name: Router
Priority Status Host
============================================================
Primary Registered 10.16.240.124
First Backup None
Second Backup None
Current active Call Manager: 10.16.240.124
Backhaul/Redundant link port: 2428
Failover Interval: 30 seconds
Keepalive Interval: 15 seconds
Last keepalive sent: 00:45:31 (elapsed time: 00:00:04)
Last MGCP traffic time: 00:45:31 (elapsed time: 00:00:04)
Last failover time: None
Switchback mode: Graceful
MGCP Fallback mode: Not Selected
Last MGCP Fallback start time: 00:00:00
Last MGCP Fallback end time: 00:00:00
PRI Backhaul Link info
Link Protocol: TCP
Remote Port Number: 2428
Remote IP Address: 10.16.240.124
Current Link State: OPEN
Statistics:
Packets recvd: 32
Recv failures: 0
Packets xmitted: 32
Xmit failures: 0
PRI Ports being backhauled: Slot 1, port 0
!
No configurations downloaded
Current state: Automatic Configuration Download feature is disabled Configuration Error
History:
FAX mode: cisco
246 Chapter 10: Configuring Voice Gateways
Although the MGCP gateway is registered, the endpoint in question might not be registered.
The show mgcp endpoints command is useful to see which endpoints have registered. The
output in Example 10-3 indicates that the T1 in slot 1/0 has registered all 24 channels as
a PRI.
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