Configuring Conferencing and Transcoding on Voice Gateways
The configuration of transcoding and conferencing on a voice gateway involves DSP resource requirements, Skinny Client Control Protocol (SCCP) configuration, DSP farm and DSP farm profile configuration, and hardware configurations.
The basic steps for configuring conferencing and transcoding on voice gateway routers are as follows:
Step 1. Determine DSP Resource Requirements: DSPs reside either directly on a voice network module (such as the NM-HD-2VE), on PVDM2s that are installed in a voice network module (such as the NM-HDV2), or on PVDM2s that are installed directly onto the motherboard (such as on the Cisco 2800 and 3800 Series voice gateway routers). You must determine the number of PVDM2s or network modules required to support your conferencing and transcoding services and install the modules on your router.
Step 2. Enable SCCP: The Cisco IOS router containing DSP resources communications with Cisco Unified Communications Manager using the SCCP. Therefore, SCCP needs to be enabled and configured on the router.
Step 3. Configure Enhanced Conferencing and Transcoding: Configuring conferencing and transcoding on the voice gateway includes the following substeps:
■ Enable DSP farm services.
■ Configure a DSP farm profile.
■ Associate a DSP Farm Profile to a Cisco Unified Communications Manager Group.
■ Verify DSP Farm configuration.
The remainder of this section explores DSP farm configuration tasks, including both Cisco IOS configuration and Cisco Unified Communications Manager configuration. Examples are provided for each configuration task.
DSP Farms
A DSP farm is the collection of DSP resources available for conferencing, transcoding, and MTP services. DSP farms are configured on the voice gateway and managed by Cisco Unified Communications Manager through SCCP.
The DSP farm can support a combination of transcoding sessions, MTP sessions, and conferences simultaneously. The DSP farm maintains the DSP resource details locally. Cisco Unified Communications Manager requests conferencing or transcoding services from the gateway, which either grants or denies these requests, depending on resource availability. The details of whether DSP resources are used, and which DSP resources are used, are transparent to Cisco Unified Communications Manager.
The DSP farm uses the DSP resources in network modules on Cisco routers to provide voice conferencing, transcoding, and hardware MTP services.
Consider the topology in Figure 2-19. Prior to actual media resource configuration, the DSPs need to be enabled for DSP farm usage. The dsp services dspfarm voice card configuration mode command allocates the DSPs to the DSP farm.
Figure 2-19 DSP Farm Configuration Topology Example
These commands are issued on both gateways, Router1 and Router2, as illustrated in Examples 2-4 and 2-5.
Example 2-4 Allocating DSPs to a DSP Farm on Routerl
Example 2-5 Allocating DSPs to a DSP Farm on Router2
DSP Profiles
DSP-farm profiles are created to allocate DSP-farm resources. Under the profile, you select the service type (conference, transcode, MTP), associate an application, and specify service-specific parameters such as codecs and the maximum number of sessions. A DSP-farm profile allows you to group DSP resources based on the service type. Applications associated with the profile, such as SCCP, can use the resources allocated under the profile. You can configure multiple profiles for the same service, each of which can register with one Cisco Unified Communications Manager group. The profile ID and service type uniquely identify a profile, allowing the profile to uniquely map to a Cisco
Unified Communications Manager group that contains a single pool of Cisco Unified Communications Manager servers.
When the DSPs are ready, the DSP profile is configured using the dspfarm profile command. In this example, because transcoding is required on Router1, the dspfarm profile 1 transcoding command is used. On Router2, the dspfarm profile 1 conferencing command creates a profile for conferencing.
Because both G.711 and G.729 are used in this deployment, multiple codecs are enabled in both the transcoding and conferencing profiles using the codec codec-type command. Configurations for Router1 and Router2 are provided in Examples 2-6 and 2-7.
Example 2-6 Creating a DSP Profile on Router1
Example 2-7 Creating a DSP Profile on Router2
Note Because mixed-mode conferencing is configured, the two configured conferences require a full DSP. If only G.711 would be allowed, a single DSP on a PVDM2 would allow up to eight conferences.
SCCP Configuration
After the profiles are set up, both routers should be configured for SCCP. As a reminder, the SCCP protocol is used for signaling between Cisco Unified Communications Manager and the router containing the DSP resources.
Both routers use their Fast Ethernet 0/1 interface as the SCCP source interface, and the primary Cisco Unified Communication Manager should be 10.1.1.201. Because Cisco Unified Communications Manager 4.1 is deployed, this is also specified in the SCCP configuration on each router to ensure full interoperability between the router and Cisco Unified Communications Manager.
After the Cisco Unified Communications Manager servers have been defined, the SCCP groups can be configured. Again, Fast Ethernet 0/1 is used as the source interface for the group, and the previously defined Cisco Unified Communications Manager is associated using the associate ccm 1 priority 1 command. Note that the San Jose Cisco Unified Communications Manager server references the identifier option previously specified.
Then, the DSP farm profile is associated with the SCCP group using the associate profile command. The register XCODERouter1 option used on Router1 assigns the name XCODERouter1 to the profile. This name will be used when registering with Cisco Unified Communications Manager and will be required when configuring the Cisco Unified Communications Manager to point back to the DSP resource. On Router2, the register CFBRouter2 option is used, because this profile is a conference bridge.
These commands are issued on both gateways, Router1 and Router2, as illustrated in Examples 2-8 and 2-9.
Example 2-8 Configuring SCCP on Router1
Example 2-9 Configuring SCCP on Router2
Unified Communications Manager Configuration
After the Cisco IOS configuration is complete, the media resources need to be added to Cisco Unified Communications Manager.
Continuing with the current example, a conference bridge is defined in the Service, Media Resource, Conference Bridge menu, as shown in Figure 2-20.
Figure 2-20 Navigating to the Conference Bridge Configuration Screen
The newly added conference bridge now needs to be set up. Because the conference bridge is using a PVDM2 deployed on an ISR, the Conference Bridge Type needs to be Cisco IOS Enhanced Conference Bridge, as illustrated in Figure 2-21.
After you select the correct type, specify the parameters described in Table 2-14 and illustrated in Figure 2-22.
Figure 2-21 Defining a Conference Bridge Type
Table 2-14 Conference Bridge Configuration
|
Parameter |
Value |
Description |
|
Conference Bridge Name |
CFBRouter2 |
This needs to match the name previously configured in the associate profile command on the gateway. |
|
Description |
CFBRouter2 |
Choose a meaningful description. |
|
Device Pool |
Default |
Select the correct device pool. |
|
Location |
< None > |
Select the correct location. |
Note For simplicity, the device pool and location are left at their defaults.
Figure 2-22 Specifying Conference Bridge Parameters
To add a transcoding resource, navigate to the Service, Media Resource, Transcoder menu option. Because PVDM2s are also used for transcoding, select Cisco IOS Enhanced Media Termination Point as the Transcoder Type. After you select the correct type, specify the parameters as described in Table 2-15 and illustrated in Figure 2-23.
Table 2-15 Transcoder Configuration
|
Parameter |
Value |
Description |
|
Transcoder Name |
XCODERouter1 |
This needs to match the name previously configured in the associate profile command on the Router1 gateway. |
|
Description |
XCODERouter1 |
Choose a meaningful description. |
|
Device Pool |
Default |
Select the correct device pool. |
|
Location |
< None > |
Select the correct location. |
|
Special Load Information |
N/A |
This should be left blank. |
Note For simplicity, the device pool and location are left at their defaults.
Figure 2-23 Specifying Transcoder Parameters
