I have a CME running on a 2821. I also have another 2821 with just fxo ports and I send all calls from the pstn to the main CME router via sip to an AA on the CME router.
The calls are extremely choppy when coming from the second 2821 router. Calls that go into the fxo on the main CME router AA sound just fine.
If I disable all the dspfarm configuration on CME, the problem seems to go away, but I need to have these configurations in.