Looking over the existing code for contact headers, it does not appear to be possible to create a sip packet with multiple URI's in the contact header, for example, a contact header like the following:
Contact:sip:55512312@xx.xx.xx.xx:5060;user=phone;q=0.5,sip:55512312@xx.xx.xx.xx:5060;user=phone;q=0.25
Any chance of adding support for this or any pointers on where to start adding support for it to the code?