This project provides an RFC 3261, 3263 complient SIP stack. This
stack is built upon a modest foot print HTTP stack. Both the SIP and
HTTP stack are intended to be usable in embedded systems. However they
are fully functional (i.e. there where no compromises made to in
functionality to achieve the ability to embed the stacks.). The
primary interface to the SIP stack it through the SipUserAgent
class. This project depends upon the sipXportLib OS abstraction layer.