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Liaison statement
Liaison Statement to IETF on location source parameter

Additional information about IETF liaison relationships is available on the IETF webpage and the Internet Architecture Board liaison webpage.
State Posted
Submitted Date 2017-06-07
From Contact Sylwia Korycinska
To Groups ART, sipcore
To Contacts Adam Roach <>
Ben Campbell <>
Alexey Melnikov <>
Adam Roach <>
Paul Kyzivat <>
Cc Jean Mahoney <>
Adam Roach <>
Session Initiation Protocol Core Discussion List <>
Ben Campbell <>
The IETF Chair <>
Alexey Melnikov <>
Brian Rosen <>
Response Contact
Purpose For action
Deadline 2017-06-22 Action Needed
Attachments NTECH(17)18_012r2_Liaison_Statement_to_IETF_on location_source_parameter.pdf
1. Overall description:

ETSI NTECH with collaboration of a number of other ETSI Technical Bodies is
developing the protocol specifications in response to the European Commission
Mandate M/493 about the determination and transport of the emergency caller

The EC Mandate requires that, the emergency caller’s location information be
provided by the Voice Service Providers (VSPs) in signalling messages they send
towards PSAPs (Public Safety Answering Points) via an Emergency Service Routing
Function (ESRF) and an Emergency Service Routing Proxy (ESRP). This information
is used to select the correct PSAP to be involved for an emergency call and to
reveal the caller's location to the selected PSAP.

The protocol specifications that ETSI is developing is based on ETSI’s
specification, ES 203 178, which provide functional requirements addressing the
mandate of the European Commission and requires to ensure distinguishing
network-provided from user-provided location information.

ETSI ES 203 178 don’t preclude the use of user-provided location information
but requires a means of being able to distinguish location information added by
a network node to the SIP message from that provided by the user equipment.

Discussions have taken place in the ETSI NTECH committee on protocol mechanisms
for implementing the requirement specified in ES 203 178. ETSI NTECH is aware
of draft-winterbottom-sipcore-locparam, that provides a solution to fulfil this
requirement and the current draft protocol specifications rely on it.

ETSI NTECH is interested in receiving information from the IETF sipcore working
group on their work plan and milestones for further developing the location
source parameter as described in draft-winterbottom-sipcore-locparam. Our goal
is to approve the protocol specifications for emergency service caller location
determination and transport in the third quarter of 2017.

2. Actions:
IETF sipcore working group to confirm that the group intends to work on the
specification of the location source parameter, and make it become an RFC, so
as to enable its use to support the emergency caller location as defined by
ETSI M493 Group.

3. Date of next meetings of the originator:
12 June 2017 – online meeting
17-19 October 2017, Sophia Antipolis (F)

(if applicable)