t1 cas cutover to PRI...looks like we may need more DSP's

Unanswered Question
Oct 6th, 2008

Can someone please respond with their experience with converting to PRI from t1 cas. My client is an outbound call center. and I want to see what other's experience was. Also, does anyone have or know the DSP per call ratio. ANy info would be appreciated.

THanks in advance

I have this problem too.
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vmoopeung Fri, 10/10/2008 - 13:23

I think PA-MCX port adapters can be used to convert t1 CAS to PRI. The PA-MCX port adapters are multichannel port adapters that provide T1/E1 connectivity for data and voice traffic. The PA-MCX ports can be configured either as DS1/PRI ports for data traffic, or as packet voice ports that, when used in conjunction with a digital voice port adapter, allow Cisco 7200 VXR routers to become dedicated packet voice hubs or packet voice gateways that connect to both private branch exchanges (PBXs) and the Public Switched Telephone Network (PSTN). This allows packet voice and packet fax calls to be placed over the WAN and sent through the gateway into the traditional circuit-switched voice infrastructure.

One of the feature of PA-MCX:

Flexible signaling support-Channel-associated signaling (CAS) and common channel signaling (CCS) support is available for both E1 and T1 applications in H.323 environments.

Refer the below URL:


DSPRM maintains a set of MAX limits (such as maximum conference sessions per DSP or maximum transcoding session per DSP) for each DSP.

Refer the below URL:


Chris Deren Fri, 10/10/2008 - 20:51

I am assuming you are converting it on the carrier side, so no additional equipment will be needed on your side. As to the DSPs you will not need any additional once as each CAS B-channel takes the same amount of DSPs as PRI B-channel. So, outside of reconfiguration of the GWs (and CM if you are using MGCP) there is not much to it.




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