Technical Summary
The Geolocation SIP header field [RFC6442] indicates that the SIP message conveys location information, which is typically provided by a user agent client (UAC), such as a person's cell phone. However, a UAC is not the only SIP element that can add geolocation information. Mobile networks also have location information about the UACs that use their networks. SIP proxies and intermediaries can add this location information to the SIP message, but there has not been a way to identify which SIP entity contributed the location information. This specification defines a new parameter for the Geolocation header field that identifies the source that added the location information to the SIP message.
Working Group Summary
This document started out in the DISPATCH working group, where it was discussed on list and presented at IETF 93. The DISPATCH plan originally was to have an AD sponsor the draft, but with the change in SIPCORE's charter allowing the WG to consider small, self-contained SIP extensions, the draft was dispatched to SIPCORE, where it was adopted.
Document Quality
The draft received extensive feedback from both DISPATCH and SIPCORE participants, and reviewers have been thanked in the Acknowledgments section.
Implementation notes: this extension to the Geolocation header field has been requested by regulatory bodies and is expected to be deployed in European mobile networks. As of this writing, there is at least one implementation.
Personnel
Who is the Document Shepherd? Jean Mahoney
Who is the Responsible Area Director? Adam Roach