DHCPv4 and DHCPv6 Options for Access Network Discovery and Selection Function (ANDSF) Discovery
The information below is for an old version of the document that is already published as an RFC.
This is an older version of an Internet-Draft that was ultimately published as RFC 6153.
|Authors||Subir Das , Gabor Bajko|
|Last updated||2015-10-14 (Latest revision 2010-10-19)|
|RFC stream||Internet Engineering Task Force (IETF)|
|IESG||IESG state||RFC 6153 (Proposed Standard)|
|Responsible AD||Jari Arkko|
|Send notices firstname.lastname@example.org|
Internet Engineering Task Force Subir Das Internet-Draft Telcordia Technologies Intended status: Proposed Standard Gabor Bajko Expires: April 21, 2011 Nokia October 19, 2010 Dynamic Host Configuration Protocol (DHCPv4 and DHCPv6) Options for Access Network Discovery and Selection Function(ANDSF) Discovery draft-das-mipshop-andsf-dhcp-options-07 Status of this Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress". The list of current Internet-Drafts can be accessed at http://www.ietf.org/1id-abstracts.html The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on April 21, 2011. Copyright and License Notice Copyright (c) 2010 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. S Das & G. Bajko Expires 04/21/11 [Page 1] ANDSF DHCP Options October 2010 Abstract This document defines new Dynamic Host Configuration Protocol (DHCPv4 and DHCPv6) options to enable a mobile node to discover Access Network Discovery and Selection Function (ANDSF) entities in an IP network. ANDSF is being developed in 3GPP and provides inter-system mobility policies and access network specific information to the mobile nodes(MNs). Table of Contents 1. Introduction .................................................2 2. ANDSF IPv4 address option for DHCPv4..........................3 3. ANDSF IPv6 address option for DHCPv6..........................4 4. Option Usage..................................................5 4.1 Usage of ANDSF Options for DHCPv4.......................5 4.2 Usage of ANDSF Options for DHCPv6.......................6 5. Security Considerations ......................................6 6. IANA Considerations ..........................................6 7. Acknowledgements .............................................7 8. References ...................................................7 8.1 Normative References ....................................7 8.2 Informative References ..................................7 Author's Addresses ..............................................7 (1) Conventions used in this document The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in [RFC2119]. (2) Terminology and abbreviations used in this document ANDSF (Access Network Discovery and Selection Function): An entity that provides network discovery and selection assistance data to the user entity (UE) as per operator policy [3GPP TS 23.402]. Access Network: A network that is accessed by the user entity(UE) 3GPP Network: A radio access network specified by Third Generation Partnership Project Non-3GPP Network: A radio access network specified outside 3GPP by Other Projects or Standards Organizations. S. Das & G. Bajko Expires 04/21/10 [Page 2] ANDSF DHCP Options October 2010 1. Introduction Access Network Discovery and Selection Function (ANDSF) is being defined in 3GPP [3GPPTS23.402] to provide necessary network discovery and selection assistance data to the mobile nodes for multi-access network scenarios where 3GPP access-network level solutions are not sufficient for the mobile nodes to perform network discovery and selection of non-3GPP networks. The information provided by ANDSF contains inter-system mobility policies and access network specific data to assist the mobile node with performing the inter-system handover. This set of information can either be provisioned in the mobile node by the home operator, or provided to the mobile node (MN) dynamically by the ANDSF over the S14 reference point as defined in [3GPPTS23.402]. In 3GPP, the ANDSF is located either in the subscriber's home operator or visited network and needs to be known to the MN or discovered by the MN. According to [3GPPTS23.402] the ANDSF is discovered through interaction with the Domain Name Service function or the DHCP Server function. This document defines new DHCPv4 and DHCPv6 options called the ANDSF IP Address Options, which allow the MN to locate an ANDSF Server. 2. ANDSF IPv4 Address Option for DHCPv4 This section describes the ANDSF IPv4 Address Option for DHCPv4. The option layout is depicted below: 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Code | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IP Address | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ . . +---------------------------------------------------------------+ Option Code OPTION-IPv4_Address-ANDSF (To Be Assigned) S. Das & G. Bajko Expires 04/21/11 [Page 3] ANDSF DHCP Options October 2010 Length Length (in bytes) of the option excluding the 'Option Code' and the 'Length' fields; Length field is set to 4N, where N is the number of IPv4 addresses carried in the option IP Address IPv4 address(es) of ANDSF Server(s) ANDSF servers MUST be listed in order of preference and the client SHOULD process them in decreasing order of preference. 3. ANDSF IPv6 Address option for DHCPv6 This section describes the ANDSF IPv6 Address Option for DHCPv6. All values in the option are represented in network byte order. The option layout is depicted below: 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Option Code | Length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | IP Address | . . +---------------------------------------------------------------+ Option Code OPTION-IPv6_Address-ANDSF (To Be Assigned) Length Length (in bytes) of the option excluding the 'Option Code' and the 'Length' fields; Length field is set to 16N, where N is the number of IPv6 addresses carried in the option S. Das & G. Bajko Expires 04/21/11 [Page 4] ANDSF DHCP Options October 2010 IP Address IPv6 address(es) of ANDSF Server(s) ANDSF servers MUST be listed in order of preference and the client SHOULD process them in decreasing order of preference. 4. Option Usage 4.1 Usage of ANDSF Options for DHCPv4 The requesting and sending of the proposed DHCPv4 options follow the rules for DHCP options in [RFC2131]. 4.1.1 Mobile Node behavior The mobile node MAY request the IP address of an ANDSF server either during initial association with a network or when the policy and access network information is required from ANDSF. It MAY also request the IP address of an ANDSF server when the network information is outdated or mobile does not have any ANDSF information. In order to request an address of a ANDSF Server, the mobile node (DHCP client) MUST include an ANDSF IPv4 Address Option in the Parameter Request List(PRL)in the respective DHCP messages as defined in [RFC2131] and [RFC2132]. The DHCP Client MAY initiate a new DHCP exchange or piggyback on other DHCP message exchanges. DHCP client handling PRL options is specified in RFC2131, Section 4.4. 4.2 Usage of ANDSF Options for DHCPv6 The requesting and sending of the proposed DHCPv6 options follow the rules for DHCP options in [RFC3315]. 4.2.1 Mobile node behavior The mobile node MAY request the IP address of an ANDSF server according to the scenarios described in Section 4.1.1. S. Das & G. Bajko Expires 04/21/11 [Page 5] ANDSF DHCP Options October 2010 In order to discover the address of an ANDSF Server, the mobile node(DHCP client) MUST include an ANDSF IPv6 Address Option in the Option Request Option (ORO) in the respective DHCP messages as defined in [RFC3315]. The DHCP client MAY initiate a new DHCP exchange or piggyback on other DHCP message exchanges. DHCP client handling ORO options is specified in RFC3315, Sections 17.1 and 18.1. 5. Security Considerations If an adversary manages to modify the response from a DHCP server or insert its own response, an MN could be led to contact a rogue ANDSF Server. A modified response could also be used to mount an amplification attack. DHCP authentication option described in [RFC3118] and [RFC3315] MAY be used to mitigate the above attacks. In deployments where DHCP authentication is not available, 3GPP specific lower layer security services can be used to protect DHCP messages[3GPPTS33.402]. 3GPP ANDSF framework also provides additional mechanisms that can also be used to mitigate above attacks and to protect message exchanges between ANDSF client and server at the higher layer [3GPPTS33.402]. 6. IANA Considerations This document defines two new DHCP options as described in Sections 2 and 3. ANDSF IPv4 Address Option for DHCPv4(OPTION-IPv4_Address-ANDSF) TBA ANDSF IPv6 Address Option for DHCPv6 (OPTION-IPv6_Address-ANDSF) TBA 7. Acknowledgements Authors would like to acknowledge the following individuals for their valuable comments. Patrick Stuper, Vijay Devarapalli, Jouni Korhonen, Jari Arkko, Ted Lemon and Ralph Droms S. Das & G. Bajko Expires 04/21/11 [Page 6] ANDSF DHCP Options October 2010 8. References 8.1 Normative References [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", RFC 2119, March 1997. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [RFC2132] S. Alexander, Droms, R. "DHCP Options and BOOTP Vendor Extensions", RFC 2132, March 1997 [RFC3315] Droms, R., et al, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003 [RFC3118] Droms, et al, "Authentication for DHCP Messages", June 2001 8.2 Informative References [3GPPTS23.402] www.3gpp.org/ftp/Specs/html-info/23402.htm 3GPP TS 23.402 V8.8.0 (2009-12): Architecture enhancements for non-3GPP accesses [3GPPTS24.302] www.3gpp.org/ftp/Specs/html-info/24302.htm 3GPP TS 24.302 V8.4.1 (2009-12): Access to the 3GPP Evolved Packet Core (EPC) via non-3GPP access Networks [3GPPTS33.402]:www.3gpp.org/ftp/Specs/html-info/33402.htm 3GPP TS 33.402 v8.6.0 (2009-120) System Architecture Evolution: Security aspects of non-3GPP accesses Authors' Addresses Subir Das Telcordia Technologies Inc. e-mail: subir(at)research(dot)Telcordia(dot)com Gabor Bajko Nokia e-mail: gabor(dot)bajko(at)nokia(dot)com S. Das & G. Bajko Expires 04/21/11 [Page 7]