I'm using the following snippet of code and keep getting a 400 code from the SBC. I am using UCMA 4.0 to do this
conversation.Impersonate("sip:helpdesk@xyz.com", "tel:+2341234678", "Help Desk");
I've figured it out. It did not like being given the sip and a phone number at the same time. Giving it only the phone number fixed the 400.
Removing the SIP uri fixed the problem.