DSP Query !

Answered Question
Jan 4th, 2010

Dear all, i am confused in gathering the reources of DSP. Currently are my assumptions so kindly correct them


1) Routers with PVDM slots can be installed with PVDM which are also called DSPs.

2) Network modules comes that have already builtin DSPs or PVDMs ?


point 2 is more confusing. Are there any NMs that comes with their own pvdm or shall we say come with their own DSPs ? Are these DSPs builtin or do we need to buy them seperately ?


I hope i am able to clear my confusion but in case if there is any pls let me know.


Thanks in advance

Correct Answer by Marwan ALshawi about 7 years 1 month ago

The NM-HDV2 has four SIMM sockets (called Banks) that hold the PVDM2 DSP cards


PVDM2 64 4 DSPs

PVDM2 48 3 DSPs

http://www.cisco.com/en/US/products/hw/modules/ps2617/products_tech_note09186a008039c316.shtml#t2a


if you have 3 PVDM64 * 4 = 12 DSPs


if you add 2 more optional NMs PVDM64 * 4 = 8


8 + 12 = 20


i think this is the way has been calculated


- Rob please, correct me if i missed something with the above calculation !!



I wish we did answer your questions and you are able now to answer your manager as well


good luck

and please rate the helpful post

Correct Answer by Rob Huffman about 7 years 1 month ago

Hi CN,


No worries my friend


The "boss" needs to understand that DSP configuration/calculation is a

real science that takes a great number of factors into consideration. In "theory"

a 2821 could be fully loaded up to support 18 DSP's but in reality the CPU

power on a 2821 is not sufficient.


Attached is a file from Jorge @ AT&T with a DSP chapter that will give you great info.




Attachments:




Hope this helps!

Rob

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Marwan ALshawi Mon, 01/04/2010 - 05:09

Cisco voice gateways use various DSP models with different capabilities. Some gateway models and Network Modules (NM) use modular DSPs, or Packet Voice DSP Modules (PVDM). Some gateways and NMs, such as the NM-HD-2V, have fixed DSPs. These NMs are provisioned with the number of DSPs required to support the voice interfaces in the NM and are not usable for any other purpose


source "Cisco Voice Gateways and Gatekeepers"


good luck

if helpful Rate

cisco.new Mon, 01/04/2010 - 05:35

Can you tell me how to identify which NMs or routers come with fixed DSPs and which ones do not ?


2) Plus if you can also help me as to what is the maximum number of pvdms/DSPs a platform can support. For example, i have a 2821 in which i install 3 pvdm-64 on motherboard, how much more can i add to it via NMs ?

Rob Huffman Mon, 01/04/2010 - 05:56

Hello CN,


Just to add a little more info to the great tips from my friend Marwan (+5 points M)


Cisco 2800 Series Integrated Services Routers


Check out Table 7 for the 2821;


PVDM (DSP) Slots on Motherboard = 3


http://www.cisco.com/en/US/prod/collateral/routers/ps5854/ps5882/product_data_sheet0900aecd8016fa68_ps5854_Products_Data_Sheet.html




or use this excellent tool from Cisco;



DSP Calculator in the following link:


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




Hope this helps!

Rob

cisco.new Mon, 01/04/2010 - 06:01

Dear Rob and Marwan, thanks alot for the support but my last query is still unanswered.


I have seen a few documents but none specify the Maximum number of Pvdm/DSP allowed on a platform ? Is there any upper threshold as to how many pvdm/DSP can reside in a platform ?

cisco.new Mon, 01/04/2010 - 06:28

Dear Sir, i hope you didnt mind my queries. Actually i am quite new to voice, just starting but my manager asked me to gather some info on few issues. This is one of them. In my search i have seen product sheets, comparison, Q&A, but i am still not able to discover, how to find the maximum number of pvdms that are allowed in any platform. For example, i am talking about 2821. So how to find the max number of DSPs can this router support ?


Pls help

Correct Answer
Rob Huffman Mon, 01/04/2010 - 06:48

Hi CN,


No worries my friend


The "boss" needs to understand that DSP configuration/calculation is a

real science that takes a great number of factors into consideration. In "theory"

a 2821 could be fully loaded up to support 18 DSP's but in reality the CPU

power on a 2821 is not sufficient.


Attached is a file from Jorge @ AT&T with a DSP chapter that will give you great info.




Attachments:




Hope this helps!

Rob

cisco.new Mon, 01/04/2010 - 08:05

Dear Sir, to be honest, this document was a bit highlevel for me. But i do understand it involves a lot of factors like codec in use, conferencing, if there is transcoding or not. But can you tell me how did you calculate total 18 DSP in 2821 ? how to calculate the max for other platforms ?

cisco.new Mon, 01/04/2010 - 23:40

Dear Marwan, thanks alot for giving me a great document but i am still confused. I know i am being stubborn or what but i am still not getting the answer to my question , pls help me out, i just wanted a straightforward answer pls


2821 has 3 slots for pvdm. More pvdm can be installed via NMs.


My simple question is, how many total pvdm can i use in a platform/model, whether it be 2821, 2851 etc. Can you tell me how Rob, told that 18 DSP can be loaded on 2821. Can you help me how did he calculate it ?


Pls help

Correct Answer
Marwan ALshawi Tue, 01/05/2010 - 00:45

The NM-HDV2 has four SIMM sockets (called Banks) that hold the PVDM2 DSP cards


PVDM2 64 4 DSPs

PVDM2 48 3 DSPs

http://www.cisco.com/en/US/products/hw/modules/ps2617/products_tech_note09186a008039c316.shtml#t2a


if you have 3 PVDM64 * 4 = 12 DSPs


if you add 2 more optional NMs PVDM64 * 4 = 8


8 + 12 = 20


i think this is the way has been calculated


- Rob please, correct me if i missed something with the above calculation !!



I wish we did answer your questions and you are able now to answer your manager as well


good luck

and please rate the helpful post

Rob Huffman Tue, 01/05/2010 - 06:49

Hi Marwan,


Your calculation is perfect my friend


The reason I cautioned Cisco-New is that the calculator will start to

spit out warnings if you try to load the 2821 up. The recommendation

at that point is to move to the 2851. When ever I'm dealing with

the "Boss" I want to be careful not to over estimate the capabilities

of the product (in this case the 2821).


When it doesn't work then the Boss is miffed. Better to

move to the higher powered device that we are sure

can handle it's requirements.


Cheers!

Rob

cisco.new Tue, 01/05/2010 - 02:00

Thanks marwan and Rob, i am really sorry if my queries were stubborn or of stupid types. But since i am new to this thats why perhaps getting nervous.


Thanks alot sir.

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