Unable to configure max sessions HW Conference Bridge

[simonmossman]

Hi all

I have setup a new HW conf bridge but I cannot configure the max sessions as below:

dspfarm profile 3 conference

codec g711ulaw
codec g711alaw
codec g729ar8
codec g729abr8
codec gsmfr
maximum sessions 4
associate application SCCP

I have also configured the HW CNF in CUCM 6.1.4 but it is not registered? Do I need to restart the media service?

Thanks

[simonmossman]

I think I have sussed the problem......

I have a PVDM2-32

It seems that the Transcoder is using the 2 available sessions from the config below

Be nice if someone can confirm if I am correct?

dspfarm profile 1 transcode
codec g711ulaw
codec g711alaw
codec g729ar8
codec g729abr8
codec gsmfr
maximum sessions 2
associate application SCCP

[dksingh · Accepted solution]

Hi there,

Chances are you do not have enough free DSP resource so you are unable to

configure max session in the conferecing profile. Under that profile, if you

try CLI  max session ?, what choice do u see?

Remember conferencing requires a dedicated DSP unlike voice and xcoding

which can share resources on the same DSP.

Use show voice dsp group all  or show voice dsp to confirm.

One more thing, you do not need to restart any CCM service for media resources

(xcoding/conf) to register and yes, u are currently configured for 2 xcoding sessions.

Use DSP Calc. to determine resource requirements:

http://www.cisco.com/cgi-bin/Support/DSP/dsp-calc.pl

HTH,

DK

[simonmossman]

Hi Dilip

Thanks for the input, much appreciated.

I have checked the DSP calc and all seems fine as I ahve a PVDM2-32 in the gateway. Are all these resources being taken by the E1? With 4 711 and 4 729 it recommends a -16 card for the job so I cannot see why?

Rgds

[Steven Holl · Accepted solution]

The E1 is 30 channels at 15 credits.  450 credits there.

PVDM32 has 2 DSPs each at 240 credits.  Thats 480 credits.

To configure a conference session on a 5510 DSP, it takes up a whole DSP, which means you need a full DSP (all 240 credits) available.  It looks like you don't have that.

With two DSPs, if you want to configure a single conference, you'd need to configure at most a 16 channel PRI and no transcoding sessions.

You can leverage the output of 'sh voice dsp group all' to shed more light on this.

[simonmossman]

Thanks Steven.......

Can I ask where you get the credit information / calculation per E1 and PVDM module? Is there a link?

So installing a PVDM64 would get me around this problem also?

Thanks

Simon

[Steven Holl]

I just know the credit amounts from doing it enough, but the best thing for you to use is the DSP calculator:

http://www.cisco.com/web/applicat/dsprecal/dsp_calc.html

Or you just configure it and watch how 'sh voice dsp group all' behaves for the amount of session which were configured.

[simonmossman]

Hi Steven

I have just used the show command you mentioned and can see exactly how the credits work...... I will mark you as correct answer chap...thanks again for taking the time out to help

Best regards

Simon