DSP Resources

[lambay2000]

Hello,

I am configuring 4 no's E1 port's  with mgcp service, On 3rd port it prompts me with the below error.It is a new router with PVDM3 64 and no conferencing and transcoding uptil now has been configured to utilize the DSP.

My question is can i configured 120 channels with PVDM3 64 ?? I have used the DSP calculator and it without transcoding/conferencing it is saying no dsp required, i am confuse so can anybody confirm to me how much  DSP will be required.

% Not enough DSP resources available to configure pri-group on controller E1 0/1/0
% The remaining dsp resources are enough for 4 time slots.
% For current codec complexity, 2 extra 16 channel dsp(s) are required to create this voice port.
yourname(config-controller)#
Mar 13 13:04:47.176: %XCCTSP_VOICE-3-NOSDB: No signaling data block is available to build the
        voice interface(0/0:15) or DSP may not be present

[Jorge Armijo · Accepted solution]

Hi, 

There are many possible scenarios that could explain what is going on, before going further, can you please post the output from:

-show diag

-show inventory

-show version

-show voice dsp group all

Remember that you can setup the codec complexity under "voice-card", and if you use "Medium or High" the calculation will be different, in addition, is there any other Voice Interface Card installed on the Router?

Let's recall few things: 1 PVDM3-64 has 480 Credits per core, since the PVDM has two cores, we have a total of 960 credits. 

http://www.cisco.com/c/en/us/products/collateral/ios-nx-os-software/ios-ip-service-level-agreements-slas/whitepaper_C11-718333.html

One single DSO on a T1-E1 consumes 15 credits if Codec Complexity Flex is being used (Default), now, some math:

E1 = 30 Bchannels 

4 E1 = 120 Bchannels

120 * 15 = 1800 Credits

You'll need at least another PVDM3-64 to support the 4 E1 interfaces.

I think you may want to verify the DSP Calculator again:

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

Router: 2951

IOS: 15.1(4)M

DSP Modules Required:
	PVDM3-128: 1

DSP Module Allocation:
Router Slot 0:		120 Voice (94%) 8 Available (6%)
	PVDM Slot 0/0: PVDM3-128

Call Volume Allocation:
Router Slot 0		Low	Med	High
	Slot 0/0: VWIC3-4MFT-T1/E1(E1)	120

BTW, I created the Calculator Session with Low Complexity, you have to make sure no g729 calls will go through the Router, otherwise, additional resources will be needed.

HTH

~jorge

[Aman Soi · Accepted solution]

Hi,

[+5] to Jorge for explaination.

you can also refer the fantatsic DOC by AOK 

https://supportforums.cisco.com/document/123126/cisco-pvdm2-and-pvdm3-dsp-creditmips-allocation

regds,

aman

[lambay2000]

Thanks Aman and george

Ur links helped me a lot.