Hi all.  Im looking at implementing a SIP T1 to our facility and Im trying to learn some things about it and what I would need.  Ive looked over a few documents, and I cant seem to get my head around what exactly is a "SIP Proxy Server".  I get the impression that its a callmanager server, but I cant seem to read anything that specifically says that.  I read that "The Cisco SIP Proxy Server is a software application that provides
call routing services in an Internet Protocol (IP) telephony network.", which sounds like what callmanager does.  Am I correct in thinking that a SIP Proxy Server IS in fact a callmanager?  Any help appreciated.