dspfarm vs dsp services dspfarm

Unanswered Question
Dec 5th, 2007

Hello,

I'm trying to figure out the difference between the "dspfarm" and "dsp services dspfarm" commands. I've seen things configured differently and I'm trying to setup our equipment the "best way."

Here are some examples of what I've seen.

voice-card 0

dspfarm

voice-card 0

no dspfarm

dsp services dspfarm

voice-card 0

dspfarm

dspservices dspfarm

Lets assume I've got a 2851 router with a MFT-T1 vwic, 2 PVDM2-32's, and we want to do transcoding. I'm assuming one PVDM2 would support the T1 and the other would support the transcoding sessions.

Would the best way to set them up be something like this: (I've left out some configuration.)

voice-card 0

dspfarm

dsp services dspfarm

voice-card 1

no dspfarm

dspfarm profile 1 transcode

max sessions 16

assoicate application sccp

The most optimized solution would be the best.

I've looked for information on the dspfarm and dsp services dspfarm command and just can't find anything solid that says use one in one situation and use another if you want to do things this way.

Thoughts?

Thanks!

Eric

I have this problem too.
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allan.thomas Wed, 12/05/2007 - 09:17

The following information was taken from the command-lookup tool. If you have access to the below tool select IOS 12.4T and enter the command 'dspfarm':-

http://tools.cisco.com/Support/CLILookup/cltSearchAction.do

In summary the dspfarm command under voice-card adds a specified voice card to those participating in a digital signal processor (DSP) resource pool.

Whereas the dsp services dspfarm enables digital-signal-processor (DSP) farm services for a particular voice network module.

DSPFARM - Usage Guidelines

DSP mapping occurs when DSP resources on one AIM or network module are available for processing of voice time-division multiplexing (TDM) streams on a different network module or on a voice/WAN interface card (VWIC). This command is used on Cisco 3660 routers with multiservice interchange (MIX) modules installed or on Cisco 2600 series routers with AIMs installed.

DSP SERVICE DSPFARM - Usage Guidelines

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 under the particular voice card.

The number of voice network modules that must be enabled for DSP-farm services depends on the number of DSPs on the module and on the maximum number of transcoding and conferencing sessions configured for the DSP farm.

Hope this helps.

Regards

Allan.

ecornwell Wed, 12/05/2007 - 14:01

If I'm understanding this correctly, the dsp services dspfarm is only needed for NM's that have built in dsps or maybe something like the NM-HDV2 and you want it to participate in the dsp farm.

Say you had something like a NM-HDV2-1T1/E1 and had a PVDM2-32 on it and a PVDM2-32 onboard, you would have the following configuration:

voice-card 0

dspfarm

voice-card 1

no dspfarm

Is that correct or am I missing something?

allan.thomas Wed, 12/05/2007 - 15:46

What you have mentioned is also my understanding, essentially the dspfarm command specifically relates to older generation modules.

Take a look at the following document link, it provides examples of configuring an NM-HDV and a NM-HDV2, and in this case DSPFARM is used specifically for the NM-HDV. Where as the NM-HDV2 is configured with 'DSP SERVICE DSPFARM':-

http://www.cisco.com/en/US/products/ps6441/products_configuration_guide_chapter09186a0080541bf3.html#wp1061433

Regards

Allan.

ecornwell Wed, 12/05/2007 - 17:41

I think my biggest problem is the fact that the 2800 series routers have builtin PVDM slots and most of the configuration guides out there are for the 2600 and 3700 series. I haven't been able to find anything about the onboard pvdms and how to treat them.

allan.thomas Thu, 12/06/2007 - 05:23

Below is an example of DSPFARM configuration which is successfully registered on a 2811.

Depending on the IOS version installed, you may find that you are limited to which CCM version you can specify for each identifier. Simply select the latest if you have version which is not listed.

The name XCD-UKVG01 associated with profile 1 in the example has to be identical to the name you configure as your IOS Enchance MTP Transcoder.:-

voice-card 0

dsp services dspfarm

!

sccp local Loopback0

sccp ccm x.x.x.x identifier 1 version ?

sccp ccm x.x.x.x identifier 2 version ?

sccp

!

sccp ccm group 1

associate ccm 1 priority 1

associate ccm 2 priority 2

associate profile 1 register XCD-UKVG01

registration retries 20

registration timeout 30

keepalive retries 5

!

dspfarm profile 1 transcode

codec g711ulaw

codec g711alaw

codec g729ar8

codec g729abr8

maximum sessions 1

associate application SCCP

!

Hope this helps

Regards

Allan.

ecornwell Thu, 12/06/2007 - 05:35

Hi Allan...

The main reason I asked this is we have 2 PVDM2-48's on onboard and one on our NM-HDV2-1T1/E1. By my calculations, I should have only needed 3 dsps for the T1's we had configured but I could only setup 16 transcoder sessions. It turns out since we had a VWIC2-2MFT-T1 in our NM, it needed an additonal DSP even though we only have one of the T1's configured.

I have another question for you while we're on the subject. You adjusted some of the sccp ccm group values. Why did you adjust those values?

Thanks!

Eric

allan.thomas Thu, 12/06/2007 - 06:59

Rather than use the default sccp timers, the timers were changed in the example I posted specifically because these hardware resources are located at a remote branch across WAN.

Ordinarily the defaults should not be a problem, however I wanted ensure that any issues with the WAN/MPLS reconverging do not result in the resources failing to register.

Regards

Allan.

ecornwell Thu, 12/06/2007 - 07:32

Ahhh that makes sense. I heavily adjusted the timers on a VG224 we had. During a simulated WAN failure, it took over 2 minutes for it to fully fail over. I was able to get it to about 45 seconds and to fail to the gateway that was setup for SRST.

Thanks for your help/discussion on this!

Eric

lagos Fri, 12/07/2007 - 15:58

Hi Eric,

dspfarm allows DSP pooling or sharing. For example, a VWIC in an NM with no DSP resources could use motherbaord dsps with dspfarm.

dsp services dspfarm allows for any unused resources to be used for transcode or conference bridge functions if that is configured. At least one voice-card must be enabled for these services.

Hope this helps,

CJ

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