I've got 8841 phones at one of my customer offices that are not able to make or receive calls. The phones will receive IP addresses and register in CM but when called or attempting to call out will fail with either silence or a fast busy. I'll then see it drop registration in CM and after a few minutes it will come back. Other offices on the same call manager in different regions are working just fine.
Solved! Go to Solution.
You should narrow down the problem:
- Does registration flap for all phones at that site?
- When a phone is registered, can it dial another phone at the same site (check partitions/CSSs/DPs accordingly)?
I got results back from that customer after I posted:
Existing SCCP phones do not flap or drop or behave in anyway like the 8841 SIP phones are
8841 phones are unable to dial in building and vice versa. When they try they get the same behaviour of a fast busy or silence and the phone(s) re-register.
On the GRE tunnel leaving the site router to the next hop. The phone was defaulting to a higher value than the circuit was capable and without the mss adjust it wasn't correcting the phone.