delay problem with DPC 2203, Arris 501 working like a charm

Hi
I have a C3 CMTS and MTA from Arris and SA.
My files don't have service flows, because the C3 create the service flows itself.
When use the Arris 501 I don't have delay, but a lot of delay wit SA DPC 2203, anyone has SIP working with C3 and DPC 2203 ?
Any idea to trace the delay cause ?

Best Regards.

Demian

Any idea about this problem ? any clue how to start to figure out whats happening ?

Thanks