Network Working Group K. Chowdhury Internet-Draft Nortel Networks Expires: February 15, 2005 P. Yegani Cisco Systems L. Madour Ericsson August 17, 2004 DHCPv6 Options for Broadcast and Multicast Control Servers draft-chowdhury-dhc-bcmcv6-option-01.txt Status of this Memo By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. 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/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. This Internet-Draft will expire on February 15, 2005. Copyright Notice Copyright (C) The Internet Society (2004). All Rights Reserved. Abstract This document defines new options for Broadcast and Multicast Service controller discovery in an IP network. Broadcast and Multicast service over 3G wireless networks are being developed at the time of writing this document. Users of this service interact with a controller in the network to derive informations that are required to receive broadcast service. Dynamic Host Configuration Protocol can Chowdhury, et al. Expires February 15, 2005 [Page 1] Internet-Draft August 2004 be used to configure the controller IPv6 addresses in the user's devices. This document defines the related options and option codes. Table of Contents 1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 4. Broadcast Service Controller Options . . . . . . . . . . . . . 6 4.1 Broadcast Service Controller Domain Name List option . . . 6 4.2 Broadcast Service Controller IPv6 address option . . . . . 6 5. Consideration for Client Operation . . . . . . . . . . . . . . 8 6. Consideration for Server Operation . . . . . . . . . . . . . . 9 7. Security Considerations . . . . . . . . . . . . . . . . . . . 10 8. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 9. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12 10. Normative References . . . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . 14 Chowdhury, et al. Expires February 15, 2005 [Page 2] Internet-Draft August 2004 1. Motivation Dynamic Host Configuration Protocol can be used to configure various non-IP address type of parameters. These parameters are required for normal operation of various services that are offered over an IP network. In 3G wirelesss network standards body such as 3GPP2 (www.3gpp2.org), broadcast and multicast service is being developed [BCMCS]. The service includes a controller component that is responsible for managing the service via interaction with the users and other network entities. The users of the service are required to know the IPv6 address of the controller entity so that they can download all the necessary information about a desired broadcast program. In a roaming environment static configuration of the controller IPv6 address becomes unrealistic. Therefore, DHCP [RFC3315] is considered to be a method to dynamically configure controller IPv6 address in the user's devices in the 3G wireless networks. DHCP can also be used to convey the fully qualified domain name of the broadcast service controller to the user. The user in turn makes DNS queries to obtain the IPv6 address of the associated broadcast service controller. In order to allow the users to discover the broadcast controllers, the clients need to request for appropriate option codes from the DHC servers using Option-Request-Option and the DHC servers need to return corresponding configuration options that carry the broadcast and multicast service controller IPv6 address or Domain Name list. The motivation for this document is to define the necessary options and option codes. Chowdhury, et al. Expires February 15, 2005 [Page 3] Internet-Draft August 2004 2. Overview The Broadcast and Multicast Service architecture in a 3G wireless network such as 3GPP2 has the following model: +------------+ +--------+ | | | | | Controller | | DHCP | | | | Server | +------------+ +--------+ | Control| Info| | | V +----+ +------------+ +------------+ | | | | | | | MN/| bearer | Radio | | Broadcast | |User|<-------| Access |<---| Content | | | | Network | | Server | +----+ +------------+ +------------+ Note that this inforamtive figure is shown here for broad understanding of how Broadcast and Multicast service works in a 3G radio network. The network elements except MN/user and the DHCP server are not relevant to the text in this document. The user interacts with the Controller to request for broadcast/ multicast program information from the network (e.g., scheduled time, multicast IP address, port numbers). The User may also be authenticated by the Controller while downloading the relevant program security related information (such as encryption key). These interactions happen via HTTP and XML. For details of Broadcast and Multicast Service operation in 3GPP2, see [BCMCS]. There may be more than one controller in the network. The user should discover the appropriate controller to request the relevant program information. Chowdhury, et al. Expires February 15, 2005 [Page 4] Internet-Draft August 2004 3. Terminology The keywords "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in RFC 2119. Chowdhury, et al. Expires February 15, 2005 [Page 5] Internet-Draft August 2004 4. Broadcast Service Controller Options This section defines the configuration options for the controller of Broadcast Service. The options in the document are specified similar to [RFC3319]. 4.1 Broadcast Service Controller Domain Name List option The option length is followed by a sequence of labels, encoded according to Section 3.1 of RFC 1035 [5]. The option MAY contain multiple domain names, but these domain names SHOULD be used to construct SRV lookups as specified in [BCMCS], rather than querying for different A records. The client MUST try the records in the order listed, applying the mechanism described in [BCMCS] for each entry. The client only resolves the subsequent domain names if attempts to contact the first one failed or yielded no common transport protocols between the client and the controller or denote a domain administratively prohibited by client's policy. Use of multiple domain names is not meant to replace the SRV records, but rather to allow a single DHCP server to indicate the broadcast controllers in the access provider's network. The DHCPv6 option for Boradcast Service Controller Domain Names has the format shown below. option-code: OPTION_BCMCS_SERVER_D (TBD) option-length: Length of the 'Broadcast Control Server Domain Name List' field in octets; variable. 0 1 2 3 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_BCMCS_SERVER_D | option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | Broadcast Control Domain Name List | | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 4.2 Broadcast Service Controller IPv6 address option This DHCP option SHALL carry one or more 128-bit IPv6 address(es) of the Broadcast Service Controller in a operators network. Chowdhury, et al. Expires February 15, 2005 [Page 6] Internet-Draft August 2004 option-code: OPTION_BCMCS_SERVER_A (TBD) option-length: Length of the 'Broadcast Control Server IPv6 address' field in octets; variable. 0 1 2 3 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_BCMCS_SERVER_A | option-length | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | Broadcast Control server-1 address (IPv6 address) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | | Broadcast Control server-2 address (IPv6 address) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ Chowdhury, et al. Expires February 15, 2005 [Page 7] Internet-Draft August 2004 5. Consideration for Client Operation A client MAY request either or both of the Broadcast Service Controller Domain Name List and the IPv6 Address options in the Options Request Option (ORO) as described in [RFC3315]. If a client receives both the Broadcast Service Controller Domain Name List and IPv6 Address options, it SHOULD use the Domain Name List option. In this case, the client MAY use the Broadcast Service Controller IPv6 Address option only if, no server in the Broadcast Service Controller Domain Name List can be resolved or reached. Chowdhury, et al. Expires February 15, 2005 [Page 8] Internet-Draft August 2004 6. Consideration for Server Operation A server MAY send a client one or both of the Broadcast Service Controller Domain Name List and Broadcast Service Controller IPv6 Address options if the server is configured to do so. If a client requests both options and the server is configured with both types of information, the server MAY send the client only one of these options if it is configured to do so. In this case the server SHOULD send the Broadcast Service Controller Domain Name List option. A server configured with the Broadcast Service Controller IPv6 Address information MUST send a client the Broadcast Service Controller IPv6 Address option if that client requested only the Broadcast Service Controller IPv6 address option and not the Broadcast Service Controller Domain Name List option in the ORO (RFC3315]). If a client requests for the Broadcast Service Controller IPv6 option and the Server is configured only with the Domain Names, the Server MUST return the Domain Names List and vice versa. The following table summarizes the server's response: Client sends in ORO Domain Name List IPv6 Address List __________________________________________________________________ Neither option SHOULD MAY Domain Name List MUST MAY IPv6 Address MAY MUST Both options SHOULD MAY Chowdhury, et al. Expires February 15, 2005 [Page 9] Internet-Draft August 2004 7. Security Considerations The security considerations in the base DHCPv6 spec [RFC3315] applies. An attacker may change information of the Broadcast Service Controller in packets that are in-tranist from DHCP server to the MN, if integrity protection is not in place. In that event, the user of the Broadcast service may be diverted to a rogue broadcast service controller. In the absence of a mutual authentication procedure between MN and the Broadcast controller, the MN may receive wrong or fraudulent information about Broadcast Service. Chowdhury, et al. Expires February 15, 2005 [Page 10] Internet-Draft August 2004 8. IANA Considerations The option codes OPTION_BCMCS_SERVER_A, OPTION_BCMCS_SERVER_D for Broadcast Service Controller Domain Name list and IPv6 address respectively Must be assigned by IANA. Chowdhury, et al. Expires February 15, 2005 [Page 11] Internet-Draft August 2004 9. Acknowledgements Thanks to the follwoing indivduals for their review and constructive comments during the development of this document: AC Mahendran, Jun Wang, Raymond Hsu, Jayshree Bharatia, Ralph Dorms, Bernie Volz. 10 Normative References [BCMCS] 3GPP2, www.3gpp2.org, "X.P0022, Broadcast and Multicast Service in cdma2000 Wireless IP Network.", October 2003. [RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [RFC3315] Droms, R., Bound, J., Volz, B., Lemon, T., Perkins, C. and M. Carney, "Dynamic Host Configuration Protocol for IPv6 (DHCPv6)", RFC 3315, July 2003. [RFC3319] Schulzrinne, H. and B. Volz, "Dynamic Host Configuration Protocol (DHCPv6) Options for Session Initiation Protocol (SIP) Servers", RFC 3319, July 2003. Authors' Addresses Kuntal Chowdhury Nortel Networks 2221 Lakeside Blvd. Richardson, TX 75082 US Phone: +1 972-685-7788 EMail: chowdury@nortelnetworks.com Parviz Yegani Cisco Systems 3625 Cisco Way San Jose, CA 95134 US Phone: +1 408-832-5729 EMail: pyegani@cisco.com Chowdhury, et al. Expires February 15, 2005 [Page 12] Internet-Draft August 2004 Lila Madour Ericsson 8400, Decarie Blvd Town of Mount Royal, Quebec H4P 2N2 CANADA Phone: +1 514-345-7900 EMail: Lila.Madour@ericsson.com Chowdhury, et al. Expires February 15, 2005 [Page 13] Internet-Draft August 2004 Intellectual Property Statement The IETF takes no position regarding the validity or scope of any Intellectual Property Rights or other rights that might be claimed to pertain to the implementation or use of the technology described in this document or the extent to which any license under such rights might or might not be available; nor does it represent that it has made any independent effort to identify any such rights. Information on the procedures with respect to rights in RFC documents can be found in BCP 78 and BCP 79. Copies of IPR disclosures made to the IETF Secretariat and any assurances of licenses to be made available, or the result of an attempt made to obtain a general license or permission for the use of such proprietary rights by implementers or users of this specification can be obtained from the IETF on-line IPR repository at http://www.ietf.org/ipr. 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Acknowledgment Funding for the RFC Editor function is currently provided by the Internet Society. Chowdhury, et al. Expires February 15, 2005 [Page 14]