[cisco-voip] T1 Clock source question

[Jeremy Bresley]

On 4/22/2015 3:23 PM, Andrew Dorsett wrote:
> Rob is correct in that you can use NMs that support DSPs on the NM to 
> have separate clocking domains.  On the new ISR4k line, we have the 
> option of placing DSPs on the T1 module (NIM) which will allow us to 
> support multiple clocking domains.  Some people are placing DSPs on 
> the NIM for the T1 interface and then DSPs on the on-board slots for 
> DSP farm applications.
>
>
One slight correction there from recent discussions with a TME on the 
ISR line.  You don't have the option of doing that on the ISR4Ks, you 
HAVE to do that.  There is no TDM bus in the ISR4Ks, so you can't share 
DSPs between a NIM and the motherboard.  So DSPFarm use requires a 
separate PVDM4 from the one being used for the NIM. Which may make a 
significant difference in what you need to order if you've been in the 
habit of ordering larger capacity PVDMs and sharing them between VWICs 
and DSPFarm in the past on ISR/ISR G2s. What we will probably do when we 
start installing ISR4Ks at our remote sites in the near future is to 
order a PVDM4-32 with the NIM to support using it for a single PRI, and 
continue getting a 32 or 64 for DSPFarm usage.

Jeremy "TheBrez" Bresley
brez at brezworks.com