Configuring Transcoding Resources

Last Updated: June 18, 2007

This chapter describes the transcoding support available in Cisco Unified Communications Manager Express (Cisco Unified CME).

Finding Feature Information in This Module

Your Cisco Unified CME version may not support all of the features documented in this module. For a list of the versions in which each feature is supported, see the "Feature Information for Transcoding Resources" section.

• Prerequisites for Transcoding Resources

• Restrictions for Transcoding Resources

• Information About Transcoding Resources

• How to Configure Transcoding Resources

• Configuration Examples for Transcoding Resources

• Where to go Next

• Additional References

• Feature Information for Transcoding Resources

Prerequisites for Transcoding Resources

•Cisco Unified CME 3.2 or a later version.

•Cisco Unified CME routers and external voice routers on the same LAN must be configured with digital signal processors (DSPs) that support transcoding.

•DSPs on the NM-HDV, NM-HDV2, NM-HD-1V, NM-HD-2V, and NM-HD-2VE can be configured for transcoding. PVDM2-xx on the Cisco 2800 series and the Cisco 3800 series motherboards can also be configured for transcoding.

Restrictions for Transcoding Resources

•Versions earlier than Cisco CME 3.2 support only G.729 for two-party voice calls.

•Transcoding between G.711 and G.729 does not support the following:

–Meet-me conferencing

–Multiple-party conferencing

–Transcoding security

Information About Transcoding Resources

To configure transcoding support, you should understand the following concepts:

• Transcoding Support

• Transcoding When a Remote Phone Uses G.729r8

• Secure DSP Farm Transcoding

Transcoding Support

Transcoding compresses and decompresses voice streams to match endpoint-device capabilities. Transcoding is required when an incoming voice stream is digitized and compressed (by means of a codec) to save bandwidth, and the local device does not support that type of compression.

Cisco CME 3.2 and later versions support transcoding between G.711 and G.729 codecs for the following features:

•Ad hoc conferencing—One or more remote conferencing parties uses G.729.

•Call transfer and forward—One leg of a Voice over IP (VoIP)-to-VoIP hairpin call uses G.711 and the other leg uses G.729. A hairpin call is an incoming call that is transferred or forwarded over the same interface from which it arrived.

•Cisco Unity Express—An H.323 or SIP call using G.729 is forwarded to Cisco Unity Express. Cisco Unity Express supports only G.711, so G.729 must be transcoded. See the Cisco Unity Express documentation at www.cisco.com/en/US/products/sw/voicesw/ps5520/tsd_products_support_series_home.html

•Music on hold (MOH)—The phone receiving MOH is part of a system that uses G.729. The G.711 MOH is transcoded into G.729 resulting in a poorer quality sound due to the lower compression of G.729.

Figure 14 provides an example of each of the four call situations described.

Figure 14 Three-Way Conferencing, Call Transfer and Forward, Cisco Unity Express, and MOH Between G.711 and G.729

Transcoding When a Remote Phone Uses G.729r8

A situation in which transcoding resources may be used is when you use the codec command to select the G.729r8 codec to help save network bandwidth for a remote IP phone. If a conference is initiated, all phones in the conference switch to G.711 mu-law. To allow the phone to retain its G.729r8 codec setting when joined to a conference, you can use the codec g729r8 dspfarm-assist command to specify that this phone's calls should use the resources of a DSP farm for transcoding. For example, there are two remote phones (A and B) and a local phone (C) that initiates a conference with them. Both A and B are configured to use the G.729r8 codec with the assistance of the DSP-farm transcoder. In the conference, the call leg from C to the conference uses the G.711 mu-law codec, and the call legs from A and B to the Cisco Unified CME router use the G.729r8 codec.

Consider your options carefully when deciding to use the codec g729r8 dspfarm-assist command. The benefit is that it allows calls to use the G.729r8 codec on the call leg between the IP phone and the Cisco Unified CME router, which saves network bandwidth. The disadvantage is that for situations requiring G.711 codecs, such as conferencing and Cisco Unity Express, DSP resources that are possibly scarce are used to transcode the call, and delay is introduced while voice is shuttled to and from the DSP. In addition, the overuse of this feature can mask configuration errors in the codec selection mechanisms involving dial peers and codec lists.

Therefore, we recommend using the codec g729r8 dspfarm-assist command sparingly and only when absolutely required for bandwidth savings or when you know the phone will be participating very little, if at all, in calls that require a G.711 codec.

Because of how Cisco Unified CME uses voice channels with Skinny Client Control Protocol (SCCP) endpoints, you must configure at least two available transcoding sessions when establishing a call that requires transcoding configured with the codec g729r8 dspfarm-assist command. Only one session is used after the voice path is established with transcoding. However, during the SCCP manipulations, a temporary session may be allocated. If this temporary session cannot be allocated, the transcoding request is not honored, and the call continues with the G.711 codec.

If the codec g729r8 dspfarm-assist command is configured for a phone and a DSP resource is not available when needed for transcoding, a phone registered to the local Cisco Unified CME router will use G.711 instead of G.729r8. This is not true for nonSCCP call legs; if DSP resources are not available for the transcoding required for a conference, for example, the conference is not created.

Secure DSP Farm Transcoding

Cisco Unified CME uses the secure transcoding DSP farm capability only in the case described in the "Transcoding When a Remote Phone Uses G.729r8" section. If a call using the codec g729r8 dspfarm-assist command is secure, Cisco Unified CME looks for a secure transcoding resource. If it cannot find one, transcoding is not done. If the call is not secure, Cisco Unified CME looks for a nonsecure transcoding resource. If it cannot find one, Cisco Unified CME looks for a secure transcoding resource. Even if Cisco Unified CME uses a secure transcoding resource, the call is not secure, and a more expensive secure DSP Farm resource is not needed for a nonsecure call because Cisco Unified CME cannot find a less expensive nonsecure transcoder.

How to Configure Transcoding Resources

This section contains the following tasks:

• Determining DSP Resources for Transcoding (required)

• Provisioning NMs or NM Farms for Transcoding (required)

• Configuring DSP Farms for NM-HDs and NM-HDV2s (required)

• Configuring DSP Farms for NM-HDVs (required)

• Modifying the Number of Transcoding Sessions for NM-HDVs (optional)

• Configuring the Cisco Unified CME Router to Act as the DSP Farm Host (optional)

• Registering the DSP Farm with Cisco Unified CME in Secure Mode (optional)

• Verifying DSP Farm Operation (optional)

• Tuning DSP Farm Performance (optional)

Determining DSP Resources for Transcoding

Transcoding is facilitated through DSPs, which are located in network modules. All network modules have single inline memory module (SIMM) sockets or packet voice/data modules (PVDM) slots that each hold a Packet Voice DSP Module (PVDM). Each PVDM holds DSPs. A router can have multiple network modules.

Figure 15 shows an NM-HDV with five SIMM sockets or PVDM slots that each hold a 12-Channel PVDM (PVDM-12). Each PVDM-12 holds three TI 549 DSPs. Each DSP supports four channels.

Figure 15 NM-HDV Supports Up to Five PVDMs

Use DSP resources to provide voice termination of the digital voice trunk group or resources for a DSP farm. DSP resources available for transcoding and not used for voice termination are referred to as a DSP farm. Figure 16 shows a DSP farm managed by Cisco Unified CME.

Figure 16 DSP Farm

Note Transcoding of G.729 calls to G.711 allows G.729 calls to participate in existing G.711 software-based, three-party conferencing, thus eliminating the need to divide DSPs between transcoding and conferencing.

To determine how many DSP voice resources are on your Cisco Unified CME router, use the show voice dsp command. To determine how many DSP farms have been configured, use the show sdspfarm sessions and show sdspfarm units commands. For more information about these commands, see the Cisco Unified Communications Manager Express Command Reference.

For information on determining if your router has the correct DSP allocation for transcoding, see the "Allocation of DSP Resources" section in the " Configuring Enhanced Conferencing and Transcoding for Voice Gateway Routers" chapter of the Cisco Unified Communications Manager and Cisco IOS Interoperability Guide.

Provisioning NMs or NM Farms for Transcoding

To provision NMs or NM farms for transcoding, you must determine the required number of PVDMs and install them in either NMs or NM farms. A single NM holds up to five PVDMs. On routers capable of holding multiple devices, NMs or NM farms can be allocated to support different functionalities.

Step 1 Determine performance requirements.

Step 2 Determine the number of transcoding sessions that your router must support.

Step 3 Determine the number of DSPs that are required.

From Table 8 or Table 9 in the "Allocation of DSP Resources" section of the " Configuring Enhanced Conferencing and Transcoding for Voice Gateway Routers" chapter of the Cisco Unified Communications Manager and Cisco IOS Interoperability Guide, determine the number of DSPs that are required to support the transcoding sessions. Note that Cisco Unified CME does not support DSP-farm conferencing, so only the transcoding portion of this discussion applies to Cisco Unified CME. If voice termination is required in addition, determine the additional number of required DSPs from the tables. For example, 16 transcoding sessions (30-ms packetization) and 4 G.711 voice calls require two DSPs.

Step 4 Determine the number of DSPs that are supportable.

From Table 4 in the "Allocation of DSP Resources" section of the " Configuring Enhanced Conferencing and Transcoding for Voice Gateway Routers" chapter of the Cisco CallManager and Cisco IOS Interoperability Guide, determine the maximum number of NMs or NM farms that your router can support.

Step 5 Verify your solution.

Ensure that your requirements fall within router capabilities, taking into account whether your router supports multiple NMs or NM farms. If necessary, reassess performance requirements.

Step 6 Install hardware to prepare your system for DSP-farm configuration.

Install PVDMs, NMs, and NM farms as needed.

What to Do Next

Choose from one of the following options:

•To set up DSP farms for NM-HDVs, see the "Configuring DSP Farms for NM-HDVs" section.

•To set up DSP farms on NM-HDs and NM-HDV2s, see the "Modifying the Number of Transcoding Sessions for NM-HDVs" section.

Configuring DSP Farms for NM-HDs and NM-HDV2s

To configure DSP farms for NM-HDs or NM-HDV2s and to configure secure transcoding profiles, perform the following procedure.

SUMMARY STEPS

1. enable

2. configure terminal

3. voice-card slot

4. dsp services dspfarm

5. exit

6. sccp local interface-type interface-number

7. sccp ccm ip-address identifier identifier-number

8. sccp

9. sccp ccm group group-number

10. bind interface interface-type interface-number

11. associate ccm identifier-number priority

12. associate profile profile-identifier register device-name

13. keepalive retries number

14. switchover method {graceful | immediate}

15. switchback method {graceful | guard timeout-guard-value | immediate | uptime uptime-timeout-value}

16. switchback interval seconds

17. exit

18. dspfarm profile profile-identifier transcode [security]

19. trustpoint trustpoint-label

20. codec codec-type

21. maximum sessions number

22. associate application sccp

23. end

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	voice-card slot Example: Router(config)# voice-card 1	Enters voice-card configuration mode and identifies the slot in the chassis in which the NM-HDV or NM-HDV farm is located.
Step 4	dsp services dspfarm Example: Router(config-voicecard)# dsp services dspfarm	Enables DSP-farm services on the NM-HDV or NM-HDV farm.
Step 5	exit Example: Router(config-voicecard)# exit	Exits voice-card configuration mode.
Step 6	sccp local interface-type interface-number Example: Router(config)# sccp local FastEthernet 0/0	Selects the local interface that the SCCP applications (transcoding and conferencing) should use to register with Cisco Unified CME. •interface-type—Interface type that the SCCP application uses to register with Cisco Unified CME. The type can be an interface address or a virtual-interface address such as Ethernet. •interface-number—Interface number that the SCCP application uses to register with Cisco Unified CME.
Step 7	sccp ccm ip-address identifier identifier-number Example: `Router(config)# sccp ccm 10.10.10.1 priority 2`	Specifies the Cisco Unified CME address. •ip-address—IP address of the Cisco Unified CME server. •identifier identifier-number—Identifier used to associate the SCCP Cisco Unified CME IP address with a Cisco Unified CME group. See the associate ccm command in Step 11. •Repeat this step to specify the address of a secondary Cisco Unified CME server.
Step 8	sccp Example: Router(config)# sccp	Enables SCCP and its associated transcoding and conferencing applications.
Step 9	sccp ccm group group-number Example: Router(config)# sccp ccm group 1	Creates a Cisco Unified CME group and enters SCCP configuration mode for Cisco Unified CME. •group-number—Number that identifies the Cisco Unified CME group. Range is 1 to 65535. There is no default value. Note A Cisco Unified CME group is a naming device under which data for the DSP farms is declared. Only one group is required. For the Cisco Unified CME group you must assign a priority to the group, associate the group with a DSP farm profile, and set the keepalive, switchback, and switchover parameters.
Step 10	bind interface interface-type interface-number Example: Router(config-sccp-ccm)# bind interface FastEthernet 0/0	(Optional) Binds an interface to a Cisco Unified CME group so that the selected interface is used for all calls that belong to the profiles that are associated to this Cisco Unified CME group. This command is optional, but we recommend it if you have more than one profile or if you are on different subnets, to ensure that the correct interface is selected.
Step 11	associate ccm identifier-number priority Example: Router(config-sccp-ccm)# associate ccm 1 priority	Associates a Cisco Unified CME with a group and establishes its priority within the group. •identifier-number—Number that identifies Cisco Unified CME. Range is 1 to 65535. There is no default value. •priority—The priority of the Cisco Unified CME router in the Cisco Unified CME group. The default is 1 because only one Cisco Unified CME group is possible. •Repeat this step to associate a secondary Cisco Unified CME server with a group.
Step 12	associate profile profile-identifier register device-name Example: Router(config-sccp-ccm)# associate profile 1 register mtp000a8eaca80	Associates a DSP farm profile with a Cisco Unified CME group. •profile-identifier—Number that identifies the DSP farm profile. Range is 1 to 65535. There is no default value. •register device-name—User-specified device name in Cisco Unified CME. The device-name must use the format of mtp mac-address, where the mac-address is the burnt-in address of the physical interface that is used to register as the SCCP device.
Step 13	keepalive retries number Example: Router(config-sccp-ccm)# keepalive retries 5	Sets the number of keepalive retries from SCCP to Cisco Unified CME. •number—Number of keepalive attempts. Range is 1 to 32. The default is 3.
Step 14	switchover method [graceful \| immediate] Example: Router(config-sccp-ccm)# switchover method immediate	Sets the switchover method that the SCCP client uses when its communication link to the active Cisco Unified CME system goes down. •graceful—Switchover happens only after all the active sessions have been terminated gracefully. •immediate—Switches over to any one of the secondary Cisco Unified CME systems immediately.
Step 15	switchback method {graceful \| guard timeout-guard-value \| immediate \| uptime uptime-timeout-value} Example: Router(config-sccp-ccm)# switchback method immediate	Sets the switch back method that the SCCP client uses when the primary or higher priority Cisco Unified CME becomes available again. •graceful—Switchback happens only after all the active sessions have been terminated gracefully. •guard timeout-guard-value—Switchback happens either when the active sessions have been terminated gracefully or when the guard timer expires, whichever happens first. Timeout value is in seconds. Range is 60 to 172800. Default is 7200. •immediate—Switches back to the higher order Cisco Unified CME immediately when the timer expires, whether there is an active connection or not. •uptime uptime-timeout-value—Initiates the uptime timer when the higher-order Cisco Unified CME system comes alive. Timeout value is in seconds. Range is 60 to 172800. Default is 7200.
Step 16	switchback interval seconds Example: Router(config-sccp-ccm)# switchback interval 5	Sets the amount of time that the DSP farm waits before polling the primary Cisco Unified CME system when the current Cisco Unified CME switchback connection fails. •seconds—Timer value, in seconds. Range is 1 to 3600. Default is 60.
Step 17	exit Example: Router(config-sccp-ccm)# exit	Exits SCCP configuration mode.
Step 18	dspfarm profile profile-identifier transcode [security] Example: Router(config)# dspfarm profile 1 transcode security	Enters DSP farm profile configuration mode and defines a profile for DSP farm services. •profile-identifier—Number that uniquely identifies a profile. Range is 1 to 65535. There is no default. •transcode—Enables profile for transcoding. •security—Enables profile for secure DSP farm services.
Step 19	trustpoint trustpoint-label Example: Router(config-dspfarm-profile)# trustpoint dspfarm	(Optional) Associates a trustpoint with a DSP farm profile.
Step 20	codec codec-type Example: Router(config-dspfarm-profile)# codec g711ulaw	Specifies the codecs supported by a DSP farm profile. •codec-type—Specifies the preferred codec. •Use CLI help to locate a list of codecs. •Repeat this step as necessary to specify all the supported codecs.
Step 21	maximum sessions number Example: Router(config-dspfarm-profile)# maximum sessions 5	Specifies the maximum number of sessions that are supported by the profile. •number—Number of sessions supported by the profile. Range is 0 to X. Default is 0. The X value is determined at run time depending on the number of resources available with the resource provider.
Step 22	associate application sccp Example: Router(config-dspfarm-profile)# associate application sccp	Associates SCCP with the DSP farm profile.
Step 23	end Example: Router(config-dspfarm-profile)# end	Returns to privileged EXEC mode.

Configuring DSP Farms for NM-HDVs

To configure DSP farms for NM-HDVs, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. voice-card slot

4. dsp services dspfarm

5. exit

6. sccp local interface-type interface-number

7. sccp ccm ip-address priority priority-number

8. sccp

9. dspfarm transcoder maximum sessions number

10. dspfarm

11. end

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	voice-card slot Example: Router(config)# voice-card 1	Enters voice-card configuration mode and identifies the slot in the chassis in which the NM-HDV or NM-HDV farm is located.
Step 4	dsp services dspfarm Example: Router(config-voicecard)# dsp services dspfarm	Enables DSP-farm services on the NM-HDV or NM-HDV farm.
Step 5	exit Example: Router(config-voicecard)# exit	Returns to global configuration mode.
Step 6	sccp local interface-type interface-number Example: Router(config)# sccp local FastEthernet 0/0	Selects the local interface that the SCCP applications (transcoding and conferencing) should use to register with Cisco Unified CME. •interface-type—Interface type that the SCCP application uses to register with Cisco Unified CME. The type can be an interface address or a virtual-interface address such as Ethernet. •interface-number—Interface number that the SCCP application uses to register with Cisco Unified CME.
Step 7	sccp ccm ip-address priority priority-number Example: `Router(config)# sccp ccm 10.10.10.1 priority 1`	Specifies the Cisco Unified CME address. •ip-address—IP address of the Cisco Unified CME server. •priority priority—Priority of the Cisco Unified CME server relative to other connected servers. Range is 1 (highest) to 4 (lowest).
Step 8	sccp Example: Router(config)# sccp	Enables SCCP and its associated transcoding and conferencing applications.
Step 9	dspfarm transcoder maximum sessions number Example: Router(config)# dspfarm transcoder maximum sessions 12	Specifies the maximum number of transcoding sessions to be supported by the DSP farm. A DSP can support up to four transcoding sessions. Note When you assign this value, take into account the number of DSPs allocated for conferencing services.
Step 10	dspfarm Example: Router(config)# dspfarm	Enables the DSP farm.
Step 11	end Example: Router(config)# end	Returns to privileged EXEC mode.

Modifying the Number of Transcoding Sessions for NM-HDVs

To modify the maximum number of transcoding sessions for NM-HDVs, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. no dspfarm

4. dspfarm transcoder maximum sessions number

5. dspfarm

6. end

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	no dspfarm Example: Router(config)# no dspfarm	Disables the DSP farm.
Step 4	dspfarm transcoder maximum sessions number Example: Router(config)# dspfarm transcoder maximum sessions 12	Specifies the maximum number of transcoding sessions to be supported by the DSP farm.
Step 5	dspfarm Example: Router(config)# dspfarm	Enables the DSP farm.
Step 6	end Example: Router(config)# end	Returns to privileged EXEC mode.

Configuring the Cisco Unified CME Router to Act as the DSP Farm Host

To configure the Cisco Unified CME router to act as the DSP farm host, perform the following tasks.

• Determining the Maximum Number of Transcoder Sessions

• Setting the Cisco Unified CME Router to Receive IP Phone Messages

• Configuring the Cisco Unified CME Router to Host a Secure DSP Farm

Determining the Maximum Number of Transcoder Sessions

To determine the maximum number of transcoder sessions that can occur at one time perform the following steps.

SUMMARY STEPS

1. dspfarm transcoder maximum sessions

2. show sdspfarm sessions

3. show sdspfarm units

4. Determine maximum number of transcoder sessions based on values in steps 2 and 3.

DETAILED STEPS

Step 1 Use the dspfarm transcoder maximum sessions command to set the maximum number of transcoder sessions you have configured.

Step 2 Use the show sdspfarm sessions command to display the number of transcoder sessions.

Step 3 Use the show sdspfarm units command to display the number of DSP farms.

Step 4 Obtain the maximum number of transcoder sessions by multiplying the number of transcoder sessions from Step 2 (configured in Step 1 using the dspfarm transcoder maximum sessions command) by the number of DSP farms from Step 3.

Setting the Cisco Unified CME Router to Receive IP Phone Messages

To set the Cisco Unified CME router to receive IP phone messages and to set the maximum number of DSP farms and transcoder sessions, perform the following steps.

Note You can unregister all active calls' transcoding streams with the sdspfarm unregister force command.

Prerequisites

Identify the MAC address of the SCCP client interface.

For example, if you have the following configuration:

interface FastEthernet 0/0

 ip address 10.5.49.160 255.255.0.0

sccp local FastEthernet 0/0

 sccp

The show interface FastEthernet 0/0 command will yield a MAC address as shown in the following output:

Router# show interface FastEthernet 0/0

FastEthernet0/0 is up, line protocol is up

Hardware is AmdFE, address is 000a.8aea.ca80 (bia 000a.8aea.ca80)

The MAC address of the Fast Ethernet interface is 000a.8aea.ca80.

SUMMARY STEPS

1. enable

2. configure terminal

3. telephony-service

4. ip source-address ip-address [port port] [any-match | strict-match]

5. sdspfarm units number

6. sdspfarm transcode sessions number

7. sdspfarm tag number device-number

8. end

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	telephony-service Example: Router(config)# telephony-service	Enters telephony-service configuration mode.
Step 4	ip source-address ip-address [port port] [any-match \| strict-match] Example: Router(config-telephony)# ip source address 10.10.10.1 port 3000	Enables a router to receive messages from Cisco Unified IP phones through the router's IP addresses and ports. •address—The range is 0 to 5. The default is 0. •port port—(Optional) TCP/IP port used for SCCP. The default is 2000. •any-match—(Optional) Disables strict IP address checking for registration. This is the default. •strict-match—(Optional) Requires strict IP address checking for registration.
Step 5	sdspfarm units number Example: Router(config-telephony)# sdspfarm units 4	Specifies the maximum number of DSP farms that are allowed to be registered to the SCCP server. •number—The range is 0 to 5. The default is 0.
Step 6	sdspfarm transcode sessions number Example: Router(config-telephony)# sdspfarm transcode sessions 40	Specifies the maximum number of transcoder sessions for G.729 allowed by the Cisco Unified CME router. •One transcoder session consists of two transcoding streams between callers using transcode. Use the maximum number of transcoding sessions and conference calls that you want your router to support at one time. •number—Range is 0 to 128. Default is 0. Note For the value of number, you can use the value obtained in step 4 in the "Determining the Maximum Number of Transcoder Sessions" section.
Step 7	sdspfarm tag number device-name Example: Router(config-telephony)# sdspfarm tag 1 mtp000a8eaca80	Permits a DSP farm unit to be registered to Cisco Unified CME and associates it with an SCCP client interface's MAC address. •number—The tag number. The range is 1 to 5. •device-name—The MAC address of the SCCP client interface, with the "mtp" prefix added.
Step 8	end Example: Router(config-telephony)# end	Returns to privileged EXEC mode.

Configuring the Cisco Unified CME Router to Host a Secure DSP Farm

You must configure the Media Encryption Secure Real-Time Transport Protocol (SRTP) feature on the Cisco Unified CME router, making it a secure Cisco Unified CME, before it can host a secure DSP farm. See "Configuring Security" for information on configuring a secure Cisco Unified CME.

Registering the DSP Farm with Cisco Unified CME in Secure Mode

The DSP farm can reside on the same router with the Cisco Unified CME or on a different router. Some of the steps in the following tasks are optional depending the location of the DSP farm.

This section contains the following tasks:

• Obtaining a Digital Certificate from a CA Server

• Copying the CA Root Certificate of the DSP Farm Router to the Cisco Unified CME Router

• Copying the CA Root Certificate of the Cisco Unified CME Router to the DSP farm Router

• Configuring Cisco Unified CME to Allow the DSP Farm to Register

• Verifying DSP Farm Registration with Cisco Unified CME

Obtaining a Digital Certificate from a CA Server

The CA server can be the same router as the DSP farm. The DSP farm router can be configured as a CA server. The configuration steps below show how to configure a CA server on the DSP farm router. Additional configurations are required for configuring CA server on an external Cisco router or using a different CA server by itself.

This section contains the following tasks:

• Configuring a CA Server (Optional)

• Creating a Trustpoint

• Authenticating and Enrolling the Certificate with the CA Server

Configuring a CA Server

Note Skip this procedure if the DSP farm resides on the same router as the Cisco Unified CME. Proceed to the "Creating a Trustpoint" section.

The CA server automatically creates a trustpoint where the certificates are stored. The automatically created trustpoint stores the CA root certificate.

Prerequisites

Cisco Unified CME 4.2 or a later version.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto pki server label

4. database level complete

5. grant auto

6. database url root-url

7. no shutdown

8. crypto pki trustpoint label

9. revocation-check crl

10. rsakeypair key-label

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	crypto pki server label Example: Router(config)# crypto pki server dspcert	Defines a label for the certificate server and enters certificate-server configuration mode. •label—Name for CA certificate server.
Step 4	database level complete Example: Router(cs-server)# database level complete	(Optional) Controls the type of data stored in the certificate enrollment database. The default if this command is not used is minimal. •complete—In addition to the information given in the minimal and names levels, each issued certificate is written to the database. Note The complete keyword produces a large amount of information; so specify an external TFTP server in which to store the data using of the database url command.
Step 5	grant auto Example: Router(cs-server)# grant auto	(Optional) Allows an automatic certificate to be issued to any requester. The recommended method and default if this command is not used is manual enrollment. Tip Use this command only during enrollment when testing and building simple networks. A security best practice is to disable this functionality using the no grant auto command after configuration so that certificates cannot be continually granted.
Step 6	database url root-url Example: Router(cs-server)# database url nvram:	(Optional) Specifies the location where all database entries for the certificate server are to be written out. If this command is not specified, all database entries are written to NVRAM. •root-url—Location where database entries will be written out. The URL can be any URL that is supported by the Cisco IOS file system. Note If the CA is going to issue a large number of certificates, select an appropriate storage location like flash or other storage device to store the certificates. Note When the storage location chosen is flash and the file system type on this device is Class B (LEFS), make sure to check free space on the device periodically and use the squeeze command to free the space used up by deleted files. This process may take several minutes and should be done during scheduled maintenance periods or off-peak hours.
Step 7	no shutdown Example: Router(cs-server)# no shutdown	(Optional) Enables the CA. Note You should use this command only after you have completely configured the CA.
Step 8	exit Example: Router(cs-server)# exit	Exits certificate-server configuration mode.
Step 9	crypto pki trustpoint label Example: Router(config)# crypto pki trustpoint dspcert	(Optional) Declares a trustpoint and enters ca-trustpoint configuration mode. •label—Name for the trustpoint. The label Note Use this command and the enrollment url command if this CA is local to the Cisco Unified CME router. These commands are not needed for a CA running on an external router. The label has to be the same as the label in Step 3.
Step 10	revocation-check crl Example: Router(ca-trustpoint)# revocation-check crl	(Optional) Checks the revocation status of a certificate and specifies one or more methods to check the status. If a second and third method are specified, each method is used only if the previous method returns an error, such as a server being down. •crl—Certificate checking is performed by a certificate revocation list (CRL). This is the default behavior.
Step 11	rsakeypair key-label Example: Router(ca-trustpoint)# rsakeypair caserver	(Optional) Specifies an RSA key pair to use with a certificate. •key-label—Name of the key pair, which is generated during enrollment if it does not already exist or if the auto-enroll regenerate command is used. Note Multiple trustpoints can share the same key.

Creating a Trustpoint

The trustpoint stores the digital certificate for the DSP farm. To create a trustpoint, perform the following procedure:

Prerequisites

Cisco Unified CME 4.2 or a later version.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto pki trustpoint label

4. enrollment url ca-url

5. serial-number none

6. fqdn none

7. ip-address none

8. subject-name [x.500-name]

9. revocation-check none

10. rsakeypair key-label

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	crypto pki trustpoint label Example: Router(config)# crypto pki trustpoint dspcert	Declares the trustpoint that your RA mode certificate server should use and enters CA-trustpoint configuration mode. •label—Name for the trustpoint and RA.
Step 4	enrollment url ca-url Example: Router(ca-trustpoint)# enrollment url http://10.3.105.40:80	Specifies the enrollment URL of the issuing CA certificate server (root certificate server). •ca-url—URL of the router on which the root CA is installed.
Step 5	serial-number none Example: Router(ca-trustpoint)# serial-number none	Specifies whether the router serial number should be included in the certificate request. •none—Specifies that a serial number will not be included in the certificate request.
Step 6	fqdn none Example: Router(ca-trustpoint)# fqdn none	Specifies a fully qualified domain name (FQDN) that will be included as "unstructuredName" in the certificate request. •none—Router FQDN will not be included in the certificate request.
Step 7	ip-address none Example: Router(ca-trustpoint)# ip-address none	Specifies a dotted IP address or an interface that will be included as "unstructuredAddress" in the certificate request. •none—Specifies that an IP address is not to be included in the certificate request.
Step 8	subject-name [x.500-name] Example: Router(ca-trustpoint)# subject-name cn=vg224, ou=ABU, o=Cisco Systems Inc.	Specifies the subject name in the certificate request. Note The example shows how to format the certificate subject name to be similar to that of an IP phone's.
Step 9	revocation-check none Example: Router(ca-trustpoint)# revocation-check none	(Optional) Checks the revocation status of a certificate and specifies one or more methods to check the status. If a second and third method are specified, each method is used only if the previous method returns an error, such as a server being down. •none—Certificate checking is not required.
Step 10	rsakeypair key-label Example: Router(ca-trustpoint)# rsakeypair dspcert	(Optional) Specifies an RSA key pair to use with a certificate. •key-label—Name of the key pair, which is generated during enrollment if it does not already exist or if the auto-enroll regenerate command is used. Note Multiple trustpoints can share the same key. The key-label is the same as the label in Step 3.

Authenticating and Enrolling the Certificate with the CA Server

Prerequisites

Cisco Unified CME 4.2 or a later version.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto pki authenticate trustpoint-label

4. crypto pki enroll trustpoint-label

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	crypto pki authenticate trustpoint-label Example: Router(config)# crypto pki authenticate dspcert	Retrieves the CA certificate and authenticates it. Checks the certificate fingerprint if prompted. •trustpoint-label—Trustpoint label. Note The trustpoint-label is the trustpoint label specified in the "Creating a Trustpoint" section.
Step 4	`crypto pki enroll trustpoint-label` Example: Router(config)# crypto pki enroll dspcert	Enrolls with the CA and obtains the certificate for this trustpoint. •trustpoint-label—Trustpoint label. Note The trustpoint-label is the trustpoint label specified in the "Creating a Trustpoint" section.

Copying the CA Root Certificate of the DSP Farm Router to the Cisco Unified CME Router

The DSP farm router and Cisco Unified CME router exchanges certificates during the registration process. These certificates are digitally signed by the CA server of the respective router. For the routers to accept each others digital certificate, they should have the CA root certificate of each other. Manually copy the CA root certificate of the DSP farm and Cisco Unified CME router to each other.

Prerequisites

Cisco Unified CME 4.2 or a later version.

SUMMARY STEPS

1. enable

2. configure terminal

3. crypto pki trustpoint name

4. enrollment terminal

5. crypto pki export trustpoint pem terminal

6. crypto pki authenticate trustpoint-label

7. You will be prompted to enter the CA certificate. Cut and paste the base 64 encoded certificate at the command line, then press Enter, and type "quit." The router prompts you to accept the certificate. Enter "yes" to accept the certificate.

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	crypto pki trustpoint label Example: Router(config)# crypto pki trustpoint dspcert	Declares the trustpoint that your RA mode certificate server should use and enters CA-trustpoint configuration mode. •label—Name for the trustpoint and RA. Note The label is the trustpoint label specified in the "Creating a Trustpoint" section.
Step 4	enrollment terminal Example: Router(ca-trustpoint)# enrollment terminal	Specifies manual cut-and-paste certificate enrollment.
Step 5	crypto pki export trustpoint pem terminal Example: Router(ca-trustpoint)# crypto pki export dspcert pem terminal	Exports certificates and RSA keys that are associated with a trustpoint in a privacy-enhanced mail (PEM)-formatted file.
Step 6	crypto pki authenticate trustpoint-label Example: Router(config)# crypto pki authenticate vg224	Retrieves the CA certificate and authenticates it. Checks the certificate fingerprint if prompted. •trustpoint-label—Trustpoint label. Note This command is optional if the CA certificate is already loaded into the configuration.
Step 7	You will be prompted to enter the CA certificate. Cut and paste the base 64 encoded certificate at the command line, then press Enter, and type "quit." The router prompts you to accept the certificate. Enter "yes" to accept the certificate.	Completes the copying of the CA root certificate of the DSP farm router to the Cisco Unified CME router.

Copying the CA Root Certificate of the Cisco Unified CME Router to the DSP farm Router

Repeat the steps in the "Copying the CA Root Certificate of the DSP Farm Router to the Cisco Unified CME Router" section in the opposite direction, that is, from Cisco Unified CME router to the DSP farm router.

Prerequisites

Cisco Unified CME 4.2 or a later version.

Configuring Cisco Unified CME to Allow the DSP Farm to Register

Prerequisites

Cisco Unified CME 4.2 or a later version.

SUMMARY STEPS

1. enable

2. configure terminal

3. telephony-service

4. sdspfarm units number

5. sdspfarm transcode sessions number

6. sdspfarm tag number device-name

7. exit

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	telephony-service Example: Router(config)# telephony-service	Enters telephony-service configuration mode.
Step 4	sdspfarm units number Example: Router(config-telephony)# sdspfarm units 1	Specifies the maximum number of digital-signal-processor (DSP) farms that are allowed to be registered to the Skinny Client Control Protocol (SCCP) server.
Step 5	sdspfarm transcode sessions number Example: Router(config-telephony)# sdspfarm transcode sessions 30	Specifies the maximum number of transcoding sessions allowed per Cisco Unified CME router. •number—Declares the number of DSP farm sessions. Valid values are numbers from 1 to 128.
Step 6	sdspfarm tag number device-name Example: Router(config-telephony)# sdspfarm tag 1 vg224	Permits a DSP farm to register to Cisco Unified CME and associates it with a SCCP client interface's MAC address. Note The device-name in this step must be the same as the device-name in the associate profile command in Step 17 of the "Configuring DSP Farms for NM-HDs and NM-HDV2s" section.
Step 7	exit Example: Router(config-telephony)# exit	Exits telephony-service configuration mode.

Verifying DSP Farm Registration with Cisco Unified CME

Use the show sdspfarm units command to verify that the DSP farm is registering with Cisco Unified CME. Use the show voice dsp group slot command to show the status of secure conferencing.

Prerequisites

Cisco Unified CME 4.2 or a later version.

show sdspfarm units: Example

Router# show sdspfarm units

mtp-2 Device:choc2851SecCFB1 TCP socket:[1]  REGISTERED

actual_stream:8 max_stream 8 IP:10.1.0.20  37043  MTP YOKO keepalive 17391

Supported codec: G711Ulaw

                 G711Alaw

                 G729

                 G729a

                 G729ab

                 GSM FR

 max-mtps:2, max-streams:60, alloc-streams:18, act-streams:0

show voice dsp: Example

Router# show voice dsp group slot 1

dsp 13:

  State: UP, firmware: 4.4.706

  Max signal/voice channel: 16/16

  Max credits: 240

  Group: FLEX_GROUP_VOICE, complexity: FLEX

    Shared credits: 180, reserved credits: 0

    Signaling channels allocated: 2

    Voice channels allocated: 0

    Credits used: 0

  Group: FLEX_GROUP_XCODE, complexity: SECURE MEDIUM

    Shared credits: 0, reserved credits: 60

    Transcoding channels allocated: 0

    Credits used: 0

dsp 14:

  State: UP, firmware: 1.0.6

  Max signal/voice channel: 16/16

  Max credits: 240

  Group: FLEX_GROUP_CONF, complexity: SECURE CONFERENCE

    Shared credits: 0, reserved credits: 240

    Conference session: 1

    Credits used: 0

Verifying DSP Farm Operation

To verify that the DSP farm is registered and running, perform the following steps in any order.

SUMMARY STEPS

1. show sccp [statistics | connections]

2. show sdspfarm units

3. show sdspfarm sessions

4. show sdspfarm sessions summary

5. show sdspfarm sessions active

6. show sccp connections details

7. debug sccp {all | errors | events | packets | parser}

8. debug dspfarm {all | errors | events | packets}

9. debug ephone mtp

DETAILED STEPS

Step 1 Use the show sccp [statistics | connections] command to display the SCCP configuration information and current status.

Router# show sccp statistics

SCCP Application Service(s) Statistics:

Profile ID:1, Service Type:Transcoding

TCP packets rx 7, tx 7

Unsupported pkts rx 1, Unrecognized pkts rx 0

Register tx 1, successful 1, rejected 0, failed 0

KeepAlive tx 0, successful 0, failed 0

OpenReceiveChannel rx 2, successful 2, failed 0

CloseReceiveChannel rx 0, successful 0, failed 0

StartMediaTransmission rx 2, successful 2, failed 0

StopMediaTransmission rx 0, successful 0, failed 0

Reset rx 0, successful 0, failed 0

MediaStreamingFailure rx 0

Switchover 0, Switchback 0

Use the show sccp connections command to display information about the connections controlled by the SCCP transcoding and conferencing applications. In the following example, the secure value of the stype field indicates that the connection is encrypted:

Router# show sccp connections

sess_id    conn_id    stype        mode codec   ripaddr       rport sport

16777222   16777409   secure-xcode sendrecv g729b   10.3.56.120   16772 19534

16777222   16777393   secure-xcode sendrecv g711u   10.3.56.50    17030 18464

Total number of active session(s) 1, and connection(s) 2

Step 2 Use the show sdspfarm units command to display the configured and registered DSP farms.

Router# show sdspfarm units

mtp-1 Device:MTP003080218a31 TCP socket:[2]  REGISTERED

actual_stream:8 max_stream 8 IP:10.10.10.3  11470  MTP YOKO keepalive 1

Supported codec:G711Ulaw

                 G711Alaw

                 G729a

                 G729ab

 max-mtps:1, max-streams:40, alloc-streams:8, act-streams:2

Step 3 Use the show sdspfarm sessions command to display the transcoding streams.

Router# show sdspfarm sessions

Stream-ID:1 mtp:1 10.10.10.3  18404  Local:2000 START

 usage:Ip-Ip

 codec:G711Ulaw64k  duration:20 vad:0 peer Stream-ID:2

Stream-ID:2 mtp:1 10.10.10.3  17502  Local:2000 START

 usage:Ip-Ip

 codec:G729AnnexA  duration:20 vad:0 peer Stream-ID:1

Stream-ID:3 mtp:1 0.0.0.0  0  Local:0 IDLE

 usage:

 codec:G711Ulaw64k  duration:20 vad:0 peer Stream-ID:0

Stream-ID:4 mtp:1 0.0.0.0  0  Local:0 IDLE

 usage:

 codec:G711Ulaw64k  duration:20 vad:0 peer Stream-ID:0

Stream-ID:5 mtp:1 0.0.0.0  0  Local:0 IDLE

 usage:

 codec:G711Ulaw64k  duration:20 vad:0 peer Stream-ID:0

Stream-ID:6 mtp:1 0.0.0.0  0  Local:0 IDLE

 usage:

 codec:G711Ulaw64k  duration:20 vad:0 peer Stream-ID:0

Stream-ID:7 mtp:1 0.0.0.0  0  Local:0 IDLE

 usage:

 codec:G711Ulaw64k  duration:20 vad:0 peer Stream-ID:0

Stream-ID:8 mtp:1 0.0.0.0  0  Local:0 IDLE

 usage:

 codec:G711Ulaw64k  duration:20 vad:0 peer Stream-ID:0

Step 4 Use the show sdspfarm sessions summary command to display a summary view the transcoding streams.

Router# show sdspfarm sessions summary

max-mtps:2, max-streams:240, alloc-streams:40, act-streams:2

  ID   MTP  State      CallID confID Usage                         Codec/Duration

==== ===== ====== =========== ====== ============================= ==============

1    2     IDLE   -1          0                                   G711Ulaw64k /20ms

2    2     IDLE   -1          0                                   G711Ulaw64k /20ms

3    2     START  -1          3      MoH  (DN=3  , CH=1) FE=TRUE  G729 /20ms

4    2     START  -1          3      MoH  (DN=3  , CH=1) FE=FALSE G711Ulaw64k /20ms

5    2     IDLE   -1          0                                   G711Ulaw64k /20ms

6    2     IDLE   -1          0                                   G711Ulaw64k /20ms

7    2     IDLE   -1          0                                   G711Ulaw64k /20ms

8    2     IDLE   -1          0                                   G711Ulaw64k /20ms

9    2     IDLE   -1          0                                   G711Ulaw64k /20ms

10   2     IDLE   -1          0                                   G711Ulaw64k /20ms

11   2     IDLE   -1          0                                   G711Ulaw64k /20ms

12   2     IDLE   -1          0                                   G711Ulaw64k /20ms

13   2     IDLE   -1          0                                   G711Ulaw64k /20ms

14   2     IDLE   -1          0                                   G711Ulaw64k /20ms

15   2     IDLE   -1          0                                   G711Ulaw64k /20ms

16   2     IDLE   -1          0                                   G711Ulaw64k /20ms

17   2     IDLE   -1          0                                   G711Ulaw64k /20ms

18   2     IDLE   -1          0                                   G711Ulaw64k /20ms

19   2     IDLE   -1          0                                   G711Ulaw64k /20ms

20   2     IDLE   -1          0                                   G711Ulaw64k /20ms

21   2     IDLE   -1          0                                   G711Ulaw64k /20ms

22   2     IDLE   -1          0                                   G711Ulaw64k /20ms

23   2     IDLE   -1          0                                   G711Ulaw64k /20ms

24   2     IDLE   -1          0                                   G711Ulaw64k /20ms

25   2     IDLE   -1          0                                   G711Ulaw64k /20ms

26   2     IDLE   -1          0                                   G711Ulaw64k /20ms

27   2     IDLE   -1          0                                   G711Ulaw64k /20ms

28   2     IDLE   -1          0                                   G711Ulaw64k /20ms

29   2     IDLE   -1          0                                   G711Ulaw64k /20ms

30   2     IDLE   -1          0                                   G711Ulaw64k /20ms

31   2     IDLE   -1          0                                   G711Ulaw64k /20ms

32   2     IDLE   -1          0                                   G711Ulaw64k /20ms

33   2     IDLE   -1          0                                   G711Ulaw64k /20ms

34   2     IDLE   -1          0                                   G711Ulaw64k /20ms

35   2     IDLE   -1          0                                   G711Ulaw64k /20ms

36   2     IDLE   -1          0                                   G711Ulaw64k /20ms

Step 5 Use the show sdspfarm sessions active command to display the transcoding streams for all active sessions.

Router# show sdspfarm sessions active

Stream-ID:1 mtp:1 10.10.10.3  18404  Local:2000 START

 usage:Ip-Ip

 codec:G711Ulaw64k  duration:20 vad:0 peer Stream-ID:2

Stream-ID:2 mtp:1 10.10.10.3  17502  Local:2000 START

 usage:Ip-Ip

 codec:G729AnnexA  duration:20 vad:0 peer Stream-ID:1

Step 6 Use the show sccp connections details command to display the SCCP connections details such as call-leg details.

Router# show sccp connections details

bridge-info(bid, cid) - Normal bridge information(Bridge id, Calleg id)

mmbridge-info(bid, cid) - Mixed mode bridge information(Bridge id, Calleg id)

sess_id    conn_id    call-id    codec   pkt-period type      bridge-info(bid, cid)   
mmbridge-info(bid, cid)

1          -          14         N/A     N/A        transmsp  All RTPSPI Callegs      N/A

1          2          15         g729a   20         rtpspi    (4,14)                  N/A

1          1          13         g711u   20         rtpspi    (3,14)                  N/A

Total number of active session(s) 1, connection(s) 2, and callegs 3

Step 7 Use the debug sccp {all | errors | events | packets | parser} command to set debugging levels for SCCP and its applications.

Step 8 Use the debug dspfarm {all | errors | events | packets} command to set debugging levels for DSP-farm service

Step 9 Use the debug ephone mtp command to enable Message Transfer Part (MTP) debugging. Use this debug command with the debug ephone mtp, debug ephone register, debug ephone state, and debug ephone pak commands.

Tuning DSP Farm Performance

To tune DSP farm performance, perform the following steps.

SUMMARY STEPS

1. enable

2. configure terminal

3. sccp ip precedence value

4. dspfarm rtp timeout seconds

5. dspfarm connection interval seconds

6. end

DETAILED STEPS


	Command or Action	Purpose
Step 1	enable Example: Router> enable	Enables privileged EXEC mode. •Enter your password if prompted.
Step 2	configure terminal Example: Router# configure terminal	Enters global configuration mode.
Step 3	sccp ip precedence value Example: Router(config)# sccp ip precedence 5	(Optional) Sets the IP precedence value to increase the priority of voice packets over connections controlled by SCCP.
Step 4	dspfarm rtp timeout seconds Example: Router(config)# dspfarm rtp timeout 60	(Optional) Configures the Real-Time Transport Protocol (RTP) timeout interval if the error condition "RTP port unreachable" occurs.
Step 5	dspfarm connection interval seconds Example: Router(config)# dspfarm connection interval 60	(Optional) Specifies how long to monitor RTP inactivity before deleting an RTP stream.
Step 6	end Example: Router(config)# end	Returns to privileged EXEC mode.

Configuration Examples for Transcoding Resources

This section contains the following examples:

• DSP Farms for NM-HDVs: Example

• DSP Farms for NM-HDs and NM-HDV2s: Example

• Cisco Unified CME Router as the DSP Farm Host: Example

DSP Farms for NM-HDVs: Example

The following example sets up a DSP farm of 4 DSPs to handle up to 16 sessions (4 sessions per DSP) on a router with an IP address of 10.5.49.160 and a priority of 1 among other servers.

voice-card 1

dsp services dspfarm

exit

sccp local FastEthernet 0/0

sccp

sccp ccm 10.5.49.160 priority 1

dspfarm transcoder maximum sessions 16

dspfarm

telephony-service

ip source-address 10.5.49.200 port 2000

sdspfarm units 4

sdspfarm transcode sessions 40

sdspfarm tag 1 mtp000a8eaca80

sdspfarm tag 2 mtp123445672012

DSP Farms for NM-HDs and NM-HDV2s: Example

The following example sets up six transcoding sessions on a router with one DSP farm, an IP address of 10.5.49.160, and a priority of 1 among servers.

voice-card 1

dsp services dspfarm

sccp local FastEthernet 0/1

sccp

sccp ccm 10.5.49.160 identifier 1

sccp ccm group 123

associate ccm 1 priority

associate profile 1 register mtp123456792012

keepalive retries 5

switchover method immediate

switchback method immediate

switchback interval 5

dspfarm profile 1 transcode

codec g711ulaw

codec g711alaw

codec g729ar8

codec g719abr8

maximum sessions 6

associate application sccp

telephony-service

ip source-address 10.5.49.200 port 2000

sdspfarm units 1

sdspfarm transcode sessions 40

sdspfarm tag 1 mtp000a8eaca80

sdspfarm tag 2 mtp123445672012

Cisco Unified CME Router as the DSP Farm Host: Example

The following example configures Cisco Unified CME router address 10.100.10.11 port 2000 to be the farm host using the DSP farm at mtp000a8eaca80 to allow for a maximum of 1 DSP farm and 16 transcoder sessions.

telephony-service

ip source address 10.100.10.11 port 2000

sdspfarm units 1

sdspfarm transcode sessions 16

sdspfarm tag 1 mtp000a8eaca80

Where to go Next

Music on Hold

Music on hold can require transcoding resources. See "Configuring Music on Hold" on page 817.

Teleworker Remote Phones

Transcoding has benefits and disadvantages for remote teleworker phones. See the discussion in "Configuring Phones to Make Basic Calls" on page 165.

Additional References

The following sections provide references related to Cisco Unified CME features.

Related Topic	Document Title
Cisco Unified CME configuration	• Cisco Unified CME Command Reference • Cisco Unified CME Documentation Roadmap
Cisco IOS commands	• Cisco IOS Voice Command Reference • Cisco IOS Software Releases 12.4T Command References
Cisco IOS configuration	• Cisco IOS Voice Configuration Library • Cisco IOS Software Releases 12.4T Configuration Guides
Phone documentation for Cisco Unified CME	• Quick Reference Cards • User Guides

Technical Assistance


Description	Link
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. If you have a valid service contract but do not have a user ID or password, you can register on Cisco.com.	http://www.cisco.com/techsupport

Feature Information for Transcoding Resources

Table 20 lists the features in this module and enhancements to the features by version.

To determine the correct Cisco IOS release to support a specific Cisco Unified CME version, see the Cisco Unified CME and Cisco IOS Software Version Compatibility Matrix at http://www.cisco.com/en/US/products/sw/voicesw/ps4625/products_documentation_roadmap09186a0080189132.html.

Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.

Note Table 20 lists the Cisco Unified CME version that introduced support for a given feature. Unless noted otherwise, subsequent versions of Cisco Unified CME software also support that feature.

Table 20 Feature Information for Transcoding Resources
Feature Name	Cisco Unified CME Version	Feature Information
Transcoding Support	3.2	Transcoding between G.711 and G.729 was introduced.
Secure Transcoding	4.2	Secure transcoding for calls using the codec g729r8 dspfarm-assist command was introduced.

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