--- 1/draft-ietf-dhc-bcmc-options-01.txt 2006-02-04 23:01:37.000000000 +0100 +++ 2/draft-ietf-dhc-bcmc-options-02.txt 2006-02-04 23:01:37.000000000 +0100 @@ -1,21 +1,21 @@ Network Working Group K. Chowdhury Internet-Draft Starent Networks -Expires: November 17, 2005 P. Yegani +Expires: December 31, 2005 P. Yegani Cisco Systems L. Madour Ericsson - May 16, 2005 + June 29, 2005 DHCP Options for Broadcast and Multicast Control Servers - draft-ietf-dhc-bcmc-options-01.txt + draft-ietf-dhc-bcmc-options-02.txt Status of this Memo By submitting this Internet-Draft, each author represents that any applicable patent or other IPR claims of which he or she is aware have been or will be disclosed, and any of which he or she becomes aware will be disclosed, in accordance with Section 6 of BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that @@ -26,364 +26,365 @@ 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 November 17, 2005. + This Internet-Draft will expire on December 31, 2005. Copyright Notice Copyright (C) The Internet Society (2005). Abstract - This document defines new options for Broadcast and Multicast Service - controller discovery in an IP network. Broadcast service is being - developed for 3rd generation (3G) cellular telephone networks. Users - of the service interact with a controller in the network via the - Mobile Node (MN) to derive information required to receive broadcast - service. Dynamic Host Configuration Protocol can be used to - configure the MN to acccess a particular controller. This document - defines the related options and option codes. + This document defines new options to discover the Broadcast and + Multicast Service (BCMCS) controller in an IP network. BCMCS is + being developed for 3rd generation (3G) cellular telephone networks. + Users of the service interact with a controller in the network via + the Mobile Node (MN) to derive information required to receive + broadcast and multicast service. Dynamic Host Configuration Protocol + can be used to configure the MN to acccess a particular controller. + This document defines the related options and option codes. Table of Contents 1. Motivation . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Overview of the 3GPP2 BCMCS Network . . . . . . . . . . . . . 4 3. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 5 - 4. Broadcast Service Controller Options . . . . . . . . . . . . . 6 - 4.1 Broadcast Service Controller Domain Name list . . . . . . 6 - 4.2 Broadcast Service Controller Domain Name List Option - for DHCPv6 . . . . . . . . . . . . . . . . . . . . . . . . 7 - 4.3 Broadcast Service Controller IPv4 address option . . . . . 8 - 4.4 Broadcast Service Controller IPv6 Address Option . . . . . 8 - 4.5 Consideration for Client Operation . . . . . . . . . . . . 9 + 4. Broadcast & Multicast Service Controller Options . . . . . . . 6 + 4.1 Broadcast & Multicast Service Controller Domain Name + list for DHCPv4 . . . . . . . . . . . . . . . . . . . . . 6 + 4.2 Broadcast & Multicast Service Controller Domain Name + List Option for DHCPv6 . . . . . . . . . . . . . . . . . . 7 + 4.3 Broadcast & Multicast Service Controller IPv4 address + option for DHCPv4 . . . . . . . . . . . . . . . . . . . . 7 + 4.4 Broadcast & Multicast Service Controller IPv6 Address + Option for DHCPv6 . . . . . . . . . . . . . . . . . . . . 8 + 4.5 Consideration for Client Operation . . . . . . . . . . . . 8 4.6 Consideration for Server Operation . . . . . . . . . . . . 9 5. Security Considerations . . . . . . . . . . . . . . . . . . . 10 6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 11 7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 12 8. Normative References . . . . . . . . . . . . . . . . . . . . . 12 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . 12 Intellectual Property and Copyright Statements . . . . . . . . 14 1. Motivation Dynamic Host Configuration Protocol [RFC2131] and [RFC3315] 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. Broadcast and multicast service (BCMCS) is one such service that is - currently being standardized in various mobile wireless standard - bodies such as 3GPP, 3GPP2 and OMA. A description of the BCMCS, for - example, in 3GPP2 can be found in [BCMCS]. + being standardized in various mobile wireless standard bodies such as + 3GPP2, OMA, and 3GPP. A description of the BCMCS as defined in 3GPP2 + can be found in [BCMCS]. - While DHCP offers necessary mechanisms for device configuration, it - lacks the information elements required to configure a mobile device - to support BCMCS. This memo defines the extensions needed for DHCP - to provide necessary configuration information to a mobile device in - a BCMCS network. + While DHCP already defines many options for device configuration, no + option exists for configuring a mobile device to use BCMCS. This + memo defines extensions for both DHCPv4 and DHCPv6 so that DHCP can + be used to provide necessary configuration information to a mobile + device about the BCMCS controllers. - DHCP is being used in 3GPP2, for example, to assist with the + DHCP is being used in 3GPP2, to assist mobile nodes (MN) with the discovery of the BCMCS Controller in a mobile operator's IP network. The BCMCS includes a controller component that is responsible for managing the service via interaction with the MN and other network - entities. + entities. In this document we will call this a BCMCS controller. An overview of the 3GPP2 BCMCS architecture is given in the next section. It provides enough information to understand the basics of the 3GPP2 BCMCS operation. Readers are encouraged to find a more detailed description in [BCMCS]. As described in [BCMCS], the MNs are required to know the IPv4 or 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's IP - address becomes unrealistic. Therefore, DHCP is considered to be a - method to dynamically configure the MNs with the IP address or the - fully qualified domain name of the controller in the 3G cellular - telephone networks. + IPv6 address of the BCMCS controller entity so that they can download + all the necessary information about a desired broadcast and/or a + multicast program. In a roaming environment static configuration of + the BCMCS controller's IP address becomes unrealistic. Therefore, + DHCP is considered to be a method to dynamically configure the MNs + with the IP address or the fully qualified domain name of the BCMCS + controller in the 3G cellular telephone networks. - In order to allow the MNs to discover the broadcast controllers, the - DHCP clients request for appropriate option codes from the DHCP - server using Parameter Request List option. The DHCP servers need to - return the corresponding configuration options that carry either - broadcast and multicast service controller's IP address or fully - qualified domain name based on configuration. This document defines - the necessary options and option codes. + In order to allow the MNs to discover the BCMCS controllers, the MNs + request the appropriate option codes from the DHCP server using + Parameter Request List option. The DHCP servers need to return the + corresponding configuration options that carry either BCMCS + controller's IP address or fully qualified domain name based on + configuration. This document defines the necessary options and + option codes. 2. Overview of the 3GPP2 BCMCS Network The Broadcast and Multicast Service architecture in a 3G cellular telephone network such as 3GPP2 has the following model: +------------+ +--------+ - | | | | + | BCMCS | | | | Controller | | DHCP | | | | Server | +------------+ +--------+ ^ Control| Info| | | V +----+ +------------+ +------------+ | | | | | | - | MN/| bearer | Radio | | Broadcast | + | MN/| bearer | Radio | | BCMCS | |User|<-------| Access |<---| Content | | | | Network | | Server | +----+ +------------+ +------------+ - Note that this figure is shown here for broad understanding of how + Note that this figure is shown here for a basic understanding of how Broadcast and Multicast service works in a 3G cellular telehone network. The network elements except MN/user and the DHCP server are not relevant to the text in this document. - The MN interacts with the Controller to request broadcast/multicast - program information from the network (e.g., scheduled time, multicast - IP address, port numbers). The MN may also be authenticated by the - Controller while downloading the relevant program security related - information (such as encryption key). These interactions may happen - via HTTP and XML. There may be more than one controller in the - network. The MN should discover the appropriate controller to - request the relevant program information. For details of Broadcast - and Multicast Service operation in 3GPP2, see [BCMCS] + The MN interacts with the BCMCS Controller to request broadcast/ + multicast program information from the network (e.g., scheduled time, + multicast IP address, port numbers). The MN may also be + authenticated by the BCMCS Controller while downloading the relevant + program security related information (such as encryption key). These + interactions may happen via HTTP and XML as defined in [BCMCS]. + There may be more than one BCMCS controller in the network. The MN + should discover the appropriate BCMCS controller to request the + relevant program information. For details of Broadcast and Multicast + Service operation in 3GPP2, see [BCMCS]. 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. -4. Broadcast Service Controller Options +4. Broadcast & Multicast Service Controller Options - This section defines the configuration option for the controller of - the broadcast service. + This section defines the configuration option for the BCMCS + controller of the broadcast and multicast service. -4.1 Broadcast Service Controller Domain Name list +4.1 Broadcast & Multicast Service Controller Domain Name list for + DHCPv4 - If the 'enc' byte has a value of 0, the encoding byte is followed by - a sequence of labels, encoded according to Section 3.1 of RFC 1035 - [RFC1035]. + The general format of the BCMCS Controller Domain list option for + DHCPv4 is as follows: + + Code Len FQDN(s) of BCMCS Controller + +-----+-----+-----+-----+-----+-----+-----+-- + | TBD1| n | s1 | s2 | s3 | s4 | s5 | ... + +-----+-----+-----+-----+-----+-----+-----+-- 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 that is administratively prohibited by client's - policy. + no common transport protocols between the client and the BCMCS + controller or denote a domain that is administratively prohibited by + client's policy. The 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 wireless access provider's network. - - Clients MAY support compression according to the encoding in Section - 4.1.4 of "Domain Names - Implementation And Specification [RFC1035]. - Since the domain names are supposed to be different domains, - compression will likely have little effect. If the length of the - domain list exceeds the maximum permissible length within a single - option (254 octets), then the domain list MUST be represented in the - DHCP message as specified in [RFC3396] . - - The DHCP option for this encoding has the following format: - - Code Len enc FQDN(s) of Broadcast Controller - +-----+-----+-----+-----+-----+-----+-----+-----+-- - | TBD | n | 0 | s1 | s2 | s3 | s4 | s5 | ... - +-----+-----+-----+-----+-----+-----+-----+-----+-- - - An example case when two controller domain names e.g. - bcmc1.example.com, bcmc2.example.com are returned will be: - - +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ - |TBD|38 | 5 |'b'|'c'|'m'|'c'|'1'| 8 |'e'|'x'|'a'|'m'|'p'|'l'|'e'| - +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ - +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ - | 3 |'c'|'o'|'m'| 5 |'b'|'c'|'m'|'c'|'2'| 8 |'e'|'x'|'a'|'m'|'p'| - +---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+---+ - +---+---+---+---+---+---+---+---+ - |'l'|'e'|'1'| 3 |'c'|'o'|'m'| - +---+---+---+---+---+---+---+ + records, but rather to allow a single DHCPv4 server to indicate the + BCMCS controllers in the wireless access provider's network. -4.2 Broadcast Service Controller Domain Name List Option for DHCPv6 + If the length of the domain list exceeds the maximum permissible + length within a single option (254 octets), then the domain list MUST + be represented in the DHCPv4 message as specified in [RFC3396] . - The option length is followed by a sequence of labels, encoded - according to Section 3.1 of RFC 1035. + An example case when two controller domain names, example.com and + example.net are returned will be: - 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 DHCPv6 server to indicate the broadcast - controllers in the access provider's network. + +----+----+----+----+----+----+----+----+----+----+----+ + |TBD1| 26 | 7 | 'e'| 'x'| 'a'| 'm'| 'p'| 'l'| 'e'| 3 | + +----+----+----+----+----+----+----+----+----+----+----+ + +----+----+----+----+----+----+----+----+----+----+----+ + |'c' | 'o'| 'm'| 0 | 'e'| 'x'| 'a'| 'm'| 'p'| 'l'| 'e'| + +----+----+----+----+----+----+----+----+----+----+----+ + +----+----+----+----+----+----+ + | 3 | 'n'| 'e'| 't'| 0 | 7 | + +----+----+----+----+----+----+ - The DHCPv6 option for Boradcast Service Controller Domain Names has - the format shown below. +4.2 Broadcast & Multicast Service Controller Domain Name List Option + for DHCPv6 - option-code: OPTION_BCMCS_SERVER_D (TBD). + The semantics and content of the DHCPv6 encoding of this option is + exactly the same as the encoding described in the previous section, + other than necessary differences between the way options are encoded + in DHCPv4 and DHCPv6. - option-length: Length of the 'Broadcast Control Server Domain Name - List' field in octets; variable. + Specifically, the DHCPv6 option for the BCMCS Control Server Domain + Names has the following format: 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 | + | BCMCS Control Server Domain Name List | | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ -4.3 Broadcast Service Controller IPv4 address option + option-code: OPTION_BCMCS_SERVER_D (TBD2). - The encoding byte (enc) is followed by a list of IPv4 addresses - indicating broadcast controller IPv4 addresses. The controllers MUST - be listed in order of preference. Its minimum length is 5, and the - length MUST be a multiple of 4 plus one. The DHCP option for this - encoding has the following format: + option-length: Length of the 'BCMCS Control Server Domain Name List' + field in octets; variable. - Code Len enc Address 1 Address 2 - +-----+-----+-----+-----+-----+-----+-----+-----+-- - | TBD | n | 1 | a1 | a2 | a3 | a4 | a1 | ... - +-----+-----+-----+-----+-----+-----+-----+-----+-- + BCMCS Control Server Domain Name List: Identical content as in + Section 4.1 -4.4 Broadcast Service Controller IPv6 Address Option +4.3 Broadcast & Multicast Service Controller IPv4 address option for + DHCPv4 - This DHCPv6 option MUST carry one or more 128-bit IPv6 address(es) of - the Broadcast Service Controller in a operators network. + The Length byte (Len) is followed by a list of IPv4 addresses + indicating BCMCS controller IPv4 addresses. The BCMCS controllers + MUST be listed in order of preference. Its minimum length is 4, and + the length MUST be a multiple of 4. The DHCPv4 option for this + encoding has the following format: - option-code: OPTION_BCMCS_SERVER_A (TBD). + Code Len Address 1 Address 2 + +-----+-----+-----+-----+-----+-----+-----+-- + |TBD3 | n | a1 | a2 | a3 | a4 | a1 | ... + +-----+-----+-----+-----+-----+-----+-----+-- - option-length: Length of the 'Broadcast Control Server IPv6 address' - field in octets; variable. +4.4 Broadcast & Multicast Service Controller IPv6 Address Option for + DHCPv6 + + This DHCPv6 option MUST carry one or more 128-bit IPv6 address(es) of + the BCMCS Controller in a operator's network. 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) | + | BCMCS Control server-1 address (IPv6 address) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | | - | Broadcast Control server-2 address (IPv6 address) | + | BCMCS Control server-2 address (IPv6 address) | | | | | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | ... | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ + option-code: OPTION_BCMCS_SERVER_A (TBD4). + + option-length: Length of the 'BCMCS Control Server IPv6 address' + field in octets; variable. + 4.5 Consideration for Client Operation - For DHCPv6, 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]. + For DHCPv6, a client MAY request either or both of the BCMCS + 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 the servers in the Broadcast - Service Controller Domain Name List can not be resolved or reached. + If a client receives both the BCMCS Controller Domain Name List and + IPv6 Address options, it SHOULD use the Domain Name List option. In + this case, the client MAY use the BCMCS Controller IPv6 Address + option only if the servers in the BCMCS Controller Domain Name List + can not be resolved or reached. 4.6 Consideration for Server Operation - A server MAY send a client either the Broadcast Service Controller - Domain Name List Option or the Broadcast Service Controller IPv6 - Address/IPv4 Address options if the server is configured to do so. + A server MAY send a client either the BCMCS Controller Domain Name + List Option or the BCMCS Controller IPv6 Address/IPv4 Address options + if the server is configured to do so. In case of DHCPv6, 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. + this case the server SHOULD send the BCMCS 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]. + A server configured with the BCMCS Controller IPv6 Address + information MUST send a client the BCMCS Controller IPv6 Address + option if that client requested only the BCMCS Controller IPv6 + address option and not the BCMCS 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. + If a client requests for the BCMCS 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 DNS name(s) MUST be concatenated and encoded using the technique + described in section 3.3 of "Domain Names - Implementation And + Specification" [RFC1035]. DNS name compression MUST NOT be used. The following table summarizes the server's response for DHCPv6: 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 5. Security Considerations The security considerations in the base DHCP spec [RFC2131] 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. + An attacker may change information of the BCMCS 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 + & Multicast service may be diverted to a rogue BCMCS controller. 6. IANA Considerations - The following option codes for Broadcast Service Controller option - must be assigned by IANA: + The following option codes for Broadcast & Multicast Service + Controller option must be assigned by IANA: - 1. Broadcast Service Controller Domain Name list (section 4.1) + 1. The BCMCS Controller Domain Name list (section 4.1) has been + assigned a value of TBD1 from the DHCPv4 option space. - 2. OPTION_BCMCS_SERVER_D (section 4.2) + 2. The BCMCS Controller Domain Name list (section 4.2) has been + assigned a value of TBD2 from the DHCPv6 option space, and a name of + OPTION_BCMCS_SERVER_D. - 3. Broadcast Service Controller IPv4 address option (section 4.3) + 3. The BCMCS Controller IPv4 address option (section 4.3) has been + assigned a value of TBD3 from the DHCPv4 option space. - 4. OPTION_BCMCS_SERVER_A (section 4.4) + 4. The BCMCS Controller IPv6 address option (section 4.4) has been + assigned a value of TBD4 from the DHCPv6 option space, and a name of + OPTION_BCMCS_SERVER_A. The DHCP options should be registered in http://www.iana.org/assignments/bootp-dhcp-extensions The DHCPv6 options should be registered in http://www.iana.org/assignments/dhcpv6-parameters 7. Acknowledgements Thanks to the following indivduals for their review and constructive comments during the development of this document: AC Mahendran, Jun Wang, Raymond Hsu, Jayshree Bharatia, Ralph Droms, - Ted Lemon, and Margaret Wasserman. + Ted Lemon, Margaret Wasserman, and Thomas Narten. 8. Normative References [BCMCS] 3GPP2, www.3gpp2.org, ftp://ftp.3gpp2.org/TSGX/Projects/X.P0022 2ndV&V.zip, "X.S0022, Broadcast and Multicast Service in cdma2000 - Wireless IP Network. (work in progress)", December 2004. + Wireless IP Network. (pending publication)", + December 2004. [RFC1035] Mockapetris, P., "Domain names - implementation and specification", STD 13, RFC 1035, November 1987. [RFC2131] Droms, R., "Dynamic Host Configuration Protocol", RFC 2131, March 1997. [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.