Network Working Group H. Schulzrinne
Request for Comments: 5223 Columbia University
Category: Standards Track J. Polk
Cisco
H. Tschofenig
Nokia Siemens Networks
August 2008
Discovering Location-to-Service Translation (LoST) Servers Using the
Dynamic Host Configuration Protocol (DHCP)
Status of This Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Abstract
The Location-to-Service Translation (LoST) Protocol describes an XML-
based protocol for mapping service identifiers and geospatial or
civic location information to service contact Uniform Resource
Locators (URLs). LoST servers can be located anywhere, but a
placement closer to the end host, e.g., in the access network, is
desirable. In disaster situations with intermittent network
connectivity, such a LoST server placement provides benefits
regarding the resiliency of emergency service communication.
This document describes how a LoST client can discover a LoST server
using the Dynamic Host Configuration Protocol (DHCP).
Schulzrinne, et al. Standards Track [Page 1]RFC 5223 DHCP-Based LoST Discovery August 2008Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . 2
3. Domain Name Encoding . . . . . . . . . . . . . . . . . . . . . 3
4. LoST Server DHCPv4 Option . . . . . . . . . . . . . . . . . . . 3
5. LoST Server DHCPv6 Option . . . . . . . . . . . . . . . . . . . 4
6. Example . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 5
7.1. DHCPv4 Option . . . . . . . . . . . . . . . . . . . . . . . 5
7.2. DHCPv6 Option . . . . . . . . . . . . . . . . . . . . . . . 5
8. Security Considerations . . . . . . . . . . . . . . . . . . . . 5
9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 5
10. References . . . . . . . . . . . . . . . . . . . . . . . . . . 6
10.1. Normative References . . . . . . . . . . . . . . . . . . . 6
10.2. Informative References . . . . . . . . . . . . . . . . . . 6
1. Introduction
The Location-to-Service Translation (LoST) Protocol [RFC5222]
describes an XML-based protocol for mapping service identifiers and
geospatial or civic location information to service contact Uniform
Resource Locators (URLs).
In order to interact with a LoST server, the LoST client needs to
discover the server's IP address. Several mechanisms can be used to
learn this address, including manual configuration. In environments
where the access network itself either deploys a LoST server or knows
a third party that operates a LoST server, DHCP can provide the end
host with a domain name. This domain name is then used as input to
the DNS-based resolution mechanism described in LoST [RFC5222] that
reuses the URI-enabled NAPTR specification (see [RFC4848]).
This document specifies a DHCPv4 and a DHCPv6 option that allows LoST
clients to discover local LoST servers.
Section 2 provides terminology. Section 3 shows the encoding of the
domain name. Section 4 describes the DHCPv4 option while Section 5
describes the DHCPv6 option, with the same functionality. IANA and
Security Considerations complete the document in Sections 7 and 8.
2. Terminology
In this document, the key words "MUST", "MUST NOT", "REQUIRED",
"SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY",
and "OPTIONAL" are to be interpreted as described in RFC 2119
[RFC2119].
Schulzrinne, et al. Standards Track [Page 2]RFC 5223 DHCP-Based LoST Discovery August 2008
Within this document, we use terminology from [RFC5012] and
[RFC5222].
3. Domain Name Encoding
This section describes the encoding of the domain name used in the
datatracker.ietf.org