pvdm-8 and pvdm-256K-8 what is the difference ?

[holker]

Per Cisco site:

pvdm-256K-8 is for 1751 router
pvdm-8 is for 1750 router


They are expensive and pvdm-8 is what I got.
I put it in Cisco 1751 router and it is recognized by IOS.
I would prefer to use it if possible.

My lab will use mix of analog and IP phones like 7960.
Is PVDM required on gateway for IP phones ?

Please advice

 

[whykap]

PVDM's are your DSP resources for the router. You need them for trunks (FXO, PRI T1, etc), transcoding, conferencing resources, etc.
If you are not doing any of that you do not need them.

 

[holker]

It looks like
pvdm-256K-8 has 256k cache comparing to the plain pvdm-8

I wonder how is the perfomance of pvdm-8 on cisco 1751.
Cisco 1750 doesn't support HC codecs and that's probably the reason for the lack of the 256k cache.