Hello, everyone. I’m the beginner of asterisk, now I have a question.
I want to connect asterisk and norte 61C by sip, and asterisk be an IVR server.
How can I do it?
Unless you have Nortel’s SIP gateway, it cannot be done via SIP.
If you have a T-1 loop available, you can setup a PRI between systems with the proper hardware in the Asterisk server.
Thank you dalenoll. 
Yes, I have a Nortel’s SIP gateway and sip license. Would you provided some document about contact Nortel PBX and Asterisk by SIP?
I have never worked with the Nortel SIP gateway. The cost and licensing issues around that are one of the reasons I began the serious push to remove Nortel from my network.
I may be able to offer help on general Nortel issues, but nothing specific to the gateway.
Dale