Technical Summary
This document defines an extension to the Session Initiation
Protocol (SIP) to convey geographic location information
from one SIP entity to another SIP entity. The SIP extension
covers end-to-end conveyance as well as location-based
routing, where SIP intermediaries make routing decisions
based upon the location of the Location Target.
Working Group Summary
This work began in the (now concluded) SIPPING working group
back in 2003, and progressed through the (also concluded)
SIP working group before being finalized in the SIPCORE
working group. The protocol mechanism underwent significant
simplification in early 2010 to reflect a better understanding
of the core requirements underpinning the work. Although
this simplification was initially controversial, the working
group did manage to achieve a rather strong consensus around
the new mechanism after some additional changes.
Document Quality
This protocol mechanism is described in the 3GPP document
24.229 as a component of certain emergency calling scenarios
in IMS-based networks. It was developed in the SIP and
SIPCORE working groups with input from GEOPRIV working group
participants.
RFC Editor Note:
(updated to apply to -09)
1) In Section 4.4
OLD
There is no guidance given in this document as to which
locationValue, when more than one was present in the SIP request,
is related to the Geolocation-Error code; meaning that, somehow
not defined here, the LR just picks one to error.
NEW
When more than one locationValue is present in a SIP request,
this mechanism provides no indication which one the Geolocation-
Error code corresponds to. If multiple errors are present, the
LR applies local policy to select one.
2) Section 4.6, fourth paragraph, first sentence:
OLD
location information via an HTTP
NEW
location information via HTTP
3) Section 8.3, registration of geolocation-http:
OLD
via an HTTP
NEW
via HTTP
4) Please change the current inclusion of TLP 3.0 section 6.b to use the TLP 4.0 section 6.b.