Cisco IOS Configuration Commands for Enhanced Media Resources
As previously demonstrated, you need to configure DSP-based media resources both on the hardware platform (for example, a Cisco IOS router) and on Cisco Unified Communications Manager. For reference, the following discussion details the Cisco IOS configuration commands for making router-based DSP resources available to Cisco Unified Communications Manager.
DSP Farm Configuration Commands for Enhanced Media Resources
Prior to creating a DSP farm profile, you need to enable the DSPs for DSP services. You do this in the respective voice card configuration mode. After you have enabled DSPs for media resources, you can configure a DSP farm profile for conferencing, transcoding, or as an MTP. The commands required to perform this initial DSP farm configuration are provided in Table 2-16.
Table 2-16 DSP Farm Configuration Mode Commands
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Command |
Description |
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voice-card slot |
To enter voice card configuration mode and configure a voice card, use the voice-card command in global configuration mode. |
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dsp services dspfarm |
The router must be equipped with one or more voice network modules that provide DSP resources. DSP resources are used only if this command is configured for the particular voice card. |
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dspfarm profile profile-identifier {conference 1 mtp 1 transcode} |
To enter DSP farm profile configuration mode and define a profile for DSP farm services, use the dspfarm profile command in global configuration mode. To delete a disabled profile, use the no form of this command. |
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If the profile is successfully created, the user enters the DSP farm profile configuration mode. Multiple profiles can be configured for the same service. If a profile is active, the user will not be allowed to delete the profile. |
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The profile identifier uniquely identifies a profile. If the service type and profile identifier are not unique, a message is displayed that asks the user to choose a different profile identifier. |
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You can choose the profile type by using one of these options: |
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■ To create a conference bridge, use the conference option. |
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■ To create a transcoder, use the transcode option. |
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■ To create a media termination point, use the MTP option. |
Within the DSP farm configuration, you need to specify the supported codecs and maximum number of sessions. This configuration directly affects the number of required DSPs, so ensure that the configuration matches the design specifications.
You also need to associate the DSP farm profile with SCCP. This is done using the associate application sccp command. The DSP farm configuration mode commands are provided in Table 2-17.
Table 2-17 DSP Farm Configuration Mode Commands
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Command |
Description |
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codec {codec-type 1 pass-through} |
To specify the codecs supported by a DSP farm profile, use the codec command in DSP farm profile configuration mode. To remove the codec, use the no form of this command. |
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Depending on the media resource, multiple codecs can be configured. Using higher complexity codecs, such as G.729, might decrease the number of sessions per DSP. |
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The pass-through option is available only for MTPs and is typically used for Cisco Unified Communications Manager 5.0 controlled RSVP-based call admission control. |
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maximum sessions number |
To specify the maximum number of sessions supported by a profile, use the maximum sessions command in DSP farm profile configuration mode. To reset to the default, use the no form of the command. |
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For conferencing, the number specifies the number of conferences, not participants. |
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associate profile sccp |
To associate the SCCP to the DSP farm profile, use the associate application command in DSP farm profile configuration mode. To remove the protocol, use the no form of this command. |
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This also requires a correct sccp group configuration to work correctly. |
SCCP Configuration Commands for Enhanced Media Resources
Configuring enhanced media resources includes the SCCP configuration that will be used to register with Cisco Unified Communications Manager. Global configuration includes the configuration of the individual Cisco Unified Communications Managers, the local SCCP interface used for signaling, and activating SCCP.
Table 2-18 DSP Farm Configuration Mode Commands
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Command |
Description |
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sccp ccm {ip-address 1 dns} identifier identifier-number [priority priority] [port port-number] [version version_number] |
To add a Cisco Unified Communications Manager server to the list of available servers and set various parameters, including the IP address or Domain Name System (DNS) name, port number, and version number, use the sccp ccm command in global configuration mode. To remove a particular server from the list, use the no form of this command. |
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You can configure up to four Cisco Unified Communications |
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Manager servers, a primary and up to three backups, to support |
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DSP farm services. To do this, use the priority option, with 1 |
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being the highest priority and 4 being the lowest. |
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To add the Cisco Unified Communications Manager server to a Cisco Unified Communications Manager group, use the associate ccm command. |
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sccp local interface-type interface-number [port port-number] |
To select the local interface that SCCP applications (transcoding and conferencing) use to register with Cisco Unified |
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Communications Manager, use the sccp local command in global configuration mode. To deselect the interface, use the no form of this command. This should be either a LAN interface or a loopback interface and needs to be reachable from Cisco |
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Unified Communications Manager. WAN interfaces should be avoided. The port option should be used only if the default port |
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2000 has been changed on Cisco Unified Communications Manager. |
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sccp |
To enable the SCCP protocol and its related applications (transcoding and conferencing), use the sccp command in global configuration mode. To disable the protocol, use the no form of this command. |
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SCCP and its related applications (transcoding and conferencing) become enabled only if DSP resources for these applications are configured, DSP-farm service is enabled, and the Cisco Unified |
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Communications Manager registration process is completed. |
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The no form of this command disables SCCP and its applications by unregistering from the active Cisco Unified |
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Communications Manager, dropping existing connections, and freeing allocated resources. |
After globally configuring SCCP, you need to create an SCCP group. An SCCP group references previously configured Cisco Unified Communications Managers and then associates a DSP profile with the group. To bind an SCCP group to a local interface, use the bind interface command. Table 2-19 describes these SCCP group configuration commands.
Table 2-19 SCCP Group Configuration Commands
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Command |
Description |
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sccp ccm group group_number |
To create a Cisco Communications Manager group and enter SCCP Cisco Unified Communications Manager configuration mode, use the sccp ccm group command in global configuration mode. To remove a particular Cisco |
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Unified Communications Manager group, use the no form of this command. |
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Use this command to group Cisco Unified Communications Manager servers that are defined with the sccp ccm command. You can use the associate profile command to associate designated DSP farm profiles so that the DSP services are controlled by the Cisco Unified Communications Manager servers in the group. |
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associate ccm identifier-number priority priority |
To associate a Cisco Unified Communications Manager with a Cisco Communications Manager group and establish its priority within the group, use the associate ccm command in the SCCP Cisco Unified Communications Manager configuration mode. To disassociate a Cisco Unified Communications Manager from a Cisco Unified Communications Manager group, use the no form of this command. |
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The identifier-number references the Cisco Unified Communications Managers that were previously configured using the sccp ccm command. |
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You can configure up to four Cisco Unified Communications Manager servers, a primary and up to three backups, to support DSP farm services. To do this, use the priority option, with 1 being the highest priority and 4 being the lowest. |
Table 2-19 SCCP Group Configuration Commands
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Command |
Description |
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associate profile profile-identifier register device-name |
To associate a DSP farm profile with a Cisco Unified Communications Manager group, use the associate profile command in SCCP Cisco Unified Communications Manager configuration mode. To disassociate a DSP farm profile from a Cisco Unified Communications Manager, use the no form of this command. The profile option references the identifier of a DSP farm profile configured using the dspfarm profile command. |
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The device name must match the name configured in Cisco Unified Communications Manager. Otherwise, the profile is not registered to Cisco Unified Communications Manager. |
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Each profile can be associated to only one Cisco Unified Communications Manager group. |
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bind interface interface-type interface-number |
To bind an interface to a Cisco Communications Manager group, use the bind interface command in SCCP Cisco Unified Communications Manager configuration mode. To unbind the selected interface, use the no form of this command. |
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The selected interface is used for all calls that belong to the profiles associated to this Cisco Unified Communications Manager group. If the interface is not selected, it uses the best interface’s Cisco IP address in the gateway. Interfaces are selected according to user requirements. If only one group interface exists, configuration is not needed. |
Verifying Media Resources
To verify the configuration of a DSP farm profile, use the show dspfarm profile command. Example 2-10 shows the DSP farm profile with ID 1 used for conferencing. Also note the "Number of Resource Configured : 2" line, which is set by the maximum session 2 command.
Example 2-10 The show dspfarm profile Command
Example 2-10 The show dspfarm profile Command
To check the DSP status used for DSP farm profiles, use the show dspfarm dsp all command. Example 2-11 shows two available DSPs configured for conferencing.
Example 2-11 The show dspfarm dsp all Command
Summary
The main topics covered in this topic are the following:
■ Because of the nature of IP networking, voice packets sent via IP are subject to certain transmission problems.
■ Several methods can be used to determine audio quality in a VoIP network.
■ QoS is used to help meet the strict requirements concerning packet loss, delay, and delay variation in a VoIP network.
■ Some challenges exist to transporting modulated data, including fax and modem calls, over IP networks.
■ Features to support fax and modem traffic include
■ Fax and Modem Pass-Through
■ Fax and Modem Relay
■ Store-and-Forward Fax
■ T.38, pass-through, and relay use special protocol enhancements available in the H.323, SIP, and MGCP call signaling protocols.
■ DTMF support is provided by Cisco IOS gateways.
■ Codecs are used to compress and decompress various types of data that would otherwise use up large amounts of bandwidth.
■ Voice sample size is a variable that can affect the total bandwidth used.
■ Several factors must be included in calculating the overhead of a VoIP call.
■ Codec choice, data-link overhead, sample size, and compressed RTP have positive and negative impacts on total bandwidth.
■ Codec complexity affects the call density.
■ DSPs enable Cisco platforms to efficiently process digital voice traffic.
■ The number of DSPs required is a key factor when deploying media resources using DSPs.
■ The configuration of transcoding and conferencing on a voice gateway involves several components.
■ DSP farm services are enabled on the voice card, and DSP profiles create the actual media resource.
■ You can verify DSP media resources using show dspfarm commands.
