[REFS[
- [4] [CITE@en[RFC 3261 - SIP: Session Initiation Protocol]] ([TIME[2014-08-15 14:48:03 +09:00]] 版) <http://tools.ietf.org/html/rfc3261#section-13.2.1>
- [2] '''[CITE@en[RFC 3261 - SIP: Session Initiation Protocol]] ([TIME[2014-08-15 14:48:03 +09:00]] 版) <http://tools.ietf.org/html/rfc3261#section-20.11>'''
- [3] [CITE@en[RFC 3261 - SIP: Session Initiation Protocol]] ([TIME[2014-08-15 14:48:03 +09:00]] 版) <http://tools.ietf.org/html/rfc3261#section-27.6>
- [1] [CITE@en[RFC 5621 - Message Body Handling in the Session Initiation Protocol (SIP)]] ([TIME[2014-09-14 07:55:49 +09:00]] 版) <http://tools.ietf.org/html/rfc5621#section-6.2>
]REFS]