I work with Ramjet and remember this particular issue.
As I recall it had to do with our switch sending a Facility message containing the calling name data. We were specifying a digit length of X digits and the Nortel was expecting a length of Y digits. I don't remember the exact length of the fields.
Normally, a CO will send the incoming setup message to the PBX and specify that an additional facility message is to follow containing the Calling Name Information Element or IE. The originating switch specifies the length of the Calling Name IE as 15 digits persay, which is the norm. In our scenario, the SanteraOne/Tekelec T-9000/Genband G9 was specifying a CNAM length of 13 digits and the Nortel Op11 was expecting the length to be 15. Therefore it generated an error on every incoming call that involved CNAM delivery.
One option might be to see if your provider offers delivery of the CNAM IE in the call setup message versus the facility message. I know that most Nortels will handle either. Outside of that I would recommend contacting Nortel support to obtain a Layer 3 trace of the PRI signaling as this error is occuring. Once you hand that trace off to Metaswitch, they should have no problems correctly identifying the source of the error and consequently offering a solution. |