INVITE sip:user@company.com SIP/2.0
To: sip:j_user@company.com
From: sip:caller@university.edu
Call-ID: 0ha0isndaksdj@10.1.1.1
Require: newfeature1, newfeature2
Proxy-Require: newfeature3, newfeature4
CSeq: 8 INVITE
Via: SIP/2.0/UDP 135.180.130.133