Please explain DSP to me!

GT-Rob

Ok so before I carefully place this $8000 device into the garbage, I was wondering if some of you voice guys could enlighten me.


I am trying to move from a 3600 router, to a 3800. The router is used for our branch offices who don't have high speed to dial into our network for some services.


Now Ive got the T1 to come up on the new router, but I only get a busy signal (or no answer) when i try to dial into it.


The only command I wasn't able to copy over from the old router, was:

ds0-group 0 timeslot 1-24 type fxs-ground-start

I get this error when I do:

Not enough DSP resources available to configure ds0-group -
The remaining dsp resources are enough for 0 time slots


Now my question is, is there a way to solve this without buying extremely expensive DSP modules?

Also, where can I see on my 3600 that DSPs are installed? Or are they? Can I use the DSP from the 3600?

pitviper

How are you terminating the voice T – with a multiflex T1 card (like VWIC-2MFT-t1)? The reason that I ask is because the 3600 doesn’t have native voice support, so the DSP resources in the 3600 are either on an AIM (won't help you), or built into the NM module. If it’s an NM, check the Cisco site to see if it’s supported in the 3800. If not then you’re going to have to get some PVDM2s in that bad boy!

georgemc

pitviper wrote: »

How are you terminating the voice T – with a multiflex T1 card (like VWIC-2MFT-t1)? The reason that I ask is because the 3600 doesn’t have native voice support, so the DSP resources in the 3600 are either on an AIM (won't help you), or built into the NM module. If it’s an NM, check the Cisco site to see if it’s supported in the 3800. If not then you’re going to have to get some PVDM2s in that bad boy!

+1

Either reuse the NM from the 3600 (which should have the DSPs on the NM, they look like memory modules but odd sized), or purchase a PVDM for the 3800. There's a good possibility that the VWICs in each unit are the same or at least interchangeable. I've done this before with a 3825 & a 3640 and it worked out great. Of course if you're worried about the real-estate (empty NM slots) on the back of the 3800 then you'll want to go with the PVDMs. Is it possible that your sales engineer expected you to reuse the NM and that's why he/she didn't spec out the PVDMs?

Of course if your 3600 was using an AIM then...you're buying a PVDM.


George
__________________

GT-Rob

in the 3845 I have:

VWIC2-1MFT-T1/E1


We had a wic2 before I believe, but it didn't support groundstart so we had to lose it.


In the 3640 im not sure, will have to check tomorrow. Ill be swapping it if I can for sure.


I wasn't around when the purchase was made, but my experience so far with our reseller has been "research it on your own, and give them the PN you need". They are cheap though.

GT-Rob

Ok, so I've installed a PVDM2-16 on the 3800, and it is now taking the command (ds0-group).


HOWEVER, it is still not working lol. When I try to dial into it, I just get a fast busy (same as before).



The configuration is practically identical to what was on the 3600 at this point. The only difference is I am using a VWIC now and an old PRI cT1 card before (which is why I have had to install the DSPs).


T1 comes up, linecode and framing are correct. Nothing has changed on the provider. I am just at a loss of what else to try.