We are currently trying to integrate a CallManager 5.1 to a Nortel CS1000 over a SIP trunk. This customer is a large Nortel VOIP shop and has stand-alone NRS servers that are not Co-resident with their signaling servers. Cisco and Nortel both have integration documents that only address the integration with a coresident NRS/SS. The problem is that we cannot get calls to work when the SIP trunk is pointed to the NRS. It will only work when pointed to the SS. This is causing call processing concerns for the customer since there could be hundreds or thousands of simultaneous calls. Any one with some information on this please reply ASAP. please reference TAC case 607092921. TAC is being very slow to respond.