Using CUCM 7.0.5, I have a T1-PRI integration to a Nortel M1 Option 51c through DMS-100. The single PSTN PRI is connected to 51c. If I set CallForwardAll on a Cisco phone to a local PSTN number, when a Nortel phone calls to that Cisco phone, it got an error of "Cause i = 0x81E3 - Information element not implemented" on cisco router. If I CFA to a long distance number, the call goes thru successfully. I unchecked "display IE" and changed numbering plan to "National" and "ISDN", it did not help.