The Location-to-Service Translation (LoST) protocol (RFC5222) is an
XML-based protocol for mapping service identifiers and geodetic or civic
location information to service URIs and service boundaries. In particular,
it can be used to determine the location-appropriate Public Safety Answering
Point (PSAP) for emergency services.
The main data structure, the <mapping> element, used for encapsulating
information about service boundaries is defined in the LoST protocol
specification and circumscribes the region within which all locations map to
the same service Uniform Resource Identifier (URI) or set of URIs for a
This document defines an XML protocol to exchange these mappings
between two nodes. This mechanism is designed for the exchange of
authoritative <mapping> elements between two entities. Exchanging cached
<mapping> elements, i.e. non-authoritative elements, is possible but not
envisioned. In any case, this document can also be used without the LoST
protocol even though the format of the <mapping> element is re-used from the
Working Group Summary
There is consensus in the WG to publish this document.
The LoST Sync protocol was implemented during the development of RFC 5222
specification. This extension has been tested in various company-internal
implementations, as reported to the wg chairs. Two open source implementations
were made available by Columbia University and by Goettingen University.
Interoperability tests between them have been made. The code produced by
Goettingen University is available (at the time of this announcement) at:
The LoST specification has experienced extensive review, including reviews
by other SDOs.