Internet Draft Network Working Group Muneyoshi Suzuki INTERNET DRAFT NTT Expires September 13, 1998 March 13, 1998 The Assignment of the Information Field and Protocol Identifier in the Q.2941 Generic Identifier and Q.2957 User-to-user Signaling for the Internet Protocol <draft-suzuki-git-uus-assignment-02.txt> Status of this Memo This document is an Internet-Draft. 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". To learn the current status of any Internet-Draft, please check the "1id-abstracts.txt" listing contained in the Internet-Drafts Shadow Directories on ftp.is.co.za (Africa), nic.nordu.net (Europe), munnari.oz.au (Pacific Rim), ds.internic.net (US East Coast), or ftp.isi.edu (US West Coast). Abstract The purpose of this document is to specify the assignment of the information field and protocol identifier in the Q.2941 Generic Identifier and Q.2957 User-to-user Signaling for the Internet protocol. The assignment, that is specified in section 4 of this document, is designed for advanced B-ISDN signaling support of the Internet protocol, especially the B-ISDN signaling support for the connection that corresponds to the session in the Internet protocol which is clarified in section 2. This specification provides an indispensable framework for the implementation of long-live session and QoS- sensitive session transfers over ATM. Suzuki Expires September, 1998 [Page 1] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 0. Background In the ITU-T SG11 Geneva meeting held in September 1997, SG11 WP1, which has responsibility for the B-ISDN signaling protocol recommendation, agreed to establish liaison with the IETF, ATM Forum, and other ITU-T Study Groups to provide B-ISDN signaling support for the Internet Protocol. ITU-T SG11 WP1 is identifying Internet services that can be supported by the existing B-ISDN signaling protocol framework, and discussing protocol modifications based on this identification. They planned to complete this identification until 3Q 1998. ITU-T SG11 WP1 will also identify Internet services that can be supported by enhancements to the current B-ISDN signaling protocol capabilities, and discuss new protocol based on this identification. They planned to complete this identification until 1Q 1999. The issues of B-ISDN support for the Internet protocol that are currently recognized by SG11 WP1 are described in [16, 17]. In the ITU-T SG11 WP1 Kochi meeting held in January 1998, WP1 decided to discuss B-ISDN signalling support for the Internet protocol based on this Internet Draft [18]. In the next ITU-T SG11 Geneva meeting that will hold in May 1998, WP1 may decide to enhance the B-ISDN signaling protocol based on this draft. If SG11 WP1 agrees on the technical aspects and develop the Awaiting-review text (initial draft) in the May 1998 meeting, expected standard development process (fastest case) after this meeting is: November 1998: Enhance the Awaiting-review text based on inputs and develop the Cooling text (Draft Recommendations to be frozen in the next meeting, if no significant technical changes are proposed in that meeting). March 1999: Freeze the Draft Recommendations and letter ballot is requested. February 2000: The Draft Recommendations are decided (final approval). To enable advanced B-ISDN signaling support for the Internet protocol promptly, liaison from IETF to ITU-T SG11 WP1 is highly appreciated. The purpose of this document is to specify the assignment of the information field and protocol identifier in the Q.2941 Generic Identifier and Q.2957 User-to-user Signaling for the Internet protocol. To enable this specification, section 5 of this document clarifies amendments to the current B-ISDN signaling protocol. ITU-T SG11 WP1 will enhance the current B-ISDN signaling protocol based on Suzuki Expires September, 1998 [Page 2] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 this clarification. Note that the assignment rule described in this document may be subject to change, so it should not be implemented until ITU-T SG11 WP1 decides to enhance the B-ISDN signaling protocol based on this request. 1. Purpose of Document The purpose of this document is to specify the assignment of the information field and protocol identifier in the Q.2941 Generic Identifier and Q.2957 User-to-user Signaling for the Internet protocol. The assignment, that is specified in section 4 of this document, is designed for advanced B-ISDN signaling support of the Internet protocol, especially the B-ISDN signaling support for the connection that corresponds to the session in the Internet protocol which is clarified in section 2. Needless to say, the purpose of this specification is not limited to this support, and it should also be applicable to other purposes. This specification provides an indispensable framework for the implementation of long-live session and QoS-sensitive session transfers over ATM. Note that this document only specifies the assignment of the information field and protocol identifier, and that it may not specify complete protocol that enables interoperable implementation. This is because it is beyond the scope of this document and will be specified in a separate document. 2. Session-related ATM Connection With the development of new multimedia applications on the current Internet, the demands for multimedia support are increasing in the IP network, which currently supports best effort communications. In particular, demands to support QoS guaranteed communications are increasing with the development of voice, audio, and video communications applications. And it may also be necessary to introduce the mechanism that can efficiently transfer the huge volume of traffic expected with these applications. The major features of B-ISDN are high speed, logical multiplexing with the VP/VC, and flexible QoS management per VC, so it is quite natural to use these distinctive functions of B-ISDN to implement a multimedia support mechanism in the IP network. The flexible QoS management and logical multiplexing functions in B-ISDN are the Suzuki Expires September, 1998 [Page 3] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 expected method of implementing the QoS guaranteed communications in the Internet. And when a long-live session is supported by a particular VC, efficient packet forwarding may be possible using the high speed and logical multiplexing of B-ISDN. This section clarifies B-ISDN signaling functions that are required when the session is supported by the VC, for advanced B-ISDN signaling support of the Internet protocol. 2.1 Long-live Session Signaling An example scenario for establishing a VC for a long-live session is shown in Fig. 2.1. Suzuki Expires September, 1998 [Page 4] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 IP Router ATM SW ATM SW IP Router +----+ Default VC +----+ | WS | +------+ UNI +-----+ +-----+ UNI +------+ | WS | +--+-+ | /->|<------+-\-/-+--------+-\-/-+------>|<-\ | +-+--+ |.....|__/ |===||==| X |========| X |==||===| \__|.....| | | | / \ | | / \ | | | +------+ +-----+ +-----+ +------+ A. New session initially forwarded over a default VC. IP Router ATM SW ATM SW IP Router +----+ Default VC +----+ | WS | +------+ UNI +-----+ +-----+ UNI +------+ | WS | +--+-+ | /->|<------+-\-/-+--------+-\-/-+------>|<-\ | +-+--+ |.....|__/ |===||==| X |========| X |==||===| \__|.....| | |<------+-/-\-+--------+-/-\-+------>| | +------+ +-----+ +-----+ +------+ New VC is set up B. New VC is set up for the long-live session. IP Router ATM SW ATM SW IP Router +----+ Default VC +----+ | WS | +------+ UNI +-----+ +-----+ UNI +------+ | WS | +--+-+ | |<------+-\-/-+--------+-\-/-+------>| | +-+--+ |.....|__ |===||==| X |========| X |==||===| __|.....| | \-->|<------+-/-\-+--------+-/-\-+------>|<--/ | +------+ +-----+ +-----+ +------+ New VC C. Transfer of the long-live session to a new VC. Fig. 2.1: Example scenario for establishing a VC for a long-live session. First, a session is multiplexed into the default VC connecting the routers. Then, if a router detects that it is a long-live session, it sets up a new VC for the session. If the new VC is established successfully, the long-live session is moved to the new VC. In this procedure involving an ATM VC setup, the B-ISDN signaling entity in the called side router must detect that the incoming call corresponds to a session of the Internet protocol and notify that fact to the IP layer entity. Based on this information, the IP layer entity moves the session to the new VC. Suzuki Expires September, 1998 [Page 5] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 Therefore, to implement this signaling procedure, the B-ISDN signaling must include an session identifier as an information element. The B-LLI, B-HLI, User-user, and Generic Identifier information elements are all capable of transferring this information. Considering the original purposes of these information elements, the most appropriate one to use is the Generic Identifier information element. 2.2 QoS-sensitive Session Signaling The major difference between QoS-sensitive session signaling and long-live session signaling is that call setup is not initiated by the detection of a long-live session, but is explicitly initiated by the setup protocol such as ST2+ and RSVP. To implement QoS-sensitive session signaling using ATM, the ATM network between the routers must forward not only the session identifier but also the setup protocol. There are two schemes for forwarding the setup protocol. One is to multiplex the protocol into a default VC connecting the routers, or to forward the protocol through a particular VC. In this case, the QoS-sensitive session and the ATM VC are established sequentially. The second scheme is to forward the setup protocol as an information element in the B-ISDN signaling. In this case, the QoS-sensitive session and the ATM VC are established simultaneously. The latter scheme has the following advantages compared with the former one. o Easier to implement. - Admission control is simplified, because admission control for the IP and ATM layers can be done simultaneously. - Watchdog timer processing is simplified, because there is no need to watch the IP layer establishment and ATM layer establishment sequentially. o If the setup protocol supports negotiation, then an ATM VC whose QoS is based on the result of negotiation can be established. However, the latter scheme, at least, cannot support a case where a PVC is used to support a QoS-sensitive session. Therefore, both procedures should be taken into account. An example of a message sequence that simultaneously establishes a QoS-sensitive session and an ATM VC is shown in Fig. 2.2. Suzuki Expires September, 1998 [Page 6] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 IP Router ATM SW ATM SW IP Router +----+ B-ISDN Signaling +----+ | WS | +------+ UNI +-----+ Setup +-----+ UNI +------+ | WS | +--+-+ | /->|<------+-\-/--Protocol--\-/-+------>|<-\ | +-+--+ |.....|__/ |===||==| X |========| X |==||===| \__|.....| | \-->|<------+-/-\-+--------+-/-\-+------>|<--/ | +------+ +-----+ Data +-----+ +------+ QoS VC N-CONNECT | | ---------->| | | | | | |->| SETUP | | | | | |------------>| | | | | |<------------| | | | | | CALL PROC |----------->| SETUP | | | | | |------------>| | | | | | |->| N-CONNECT | | | | | |----------> | | | | | |<---------- | | | | CONN |<-| N-CONNECT-ACK | | | |<------------| | | | | |------------>| | | | CONN |<-----------| CONN ACK |->| | |<------------| | | | | |------------>| | | | |<-| CONN ACK | | | | <----------| | | | | | N-CONNECT | | -ACK Fig. 2.2: Example procedure for simultaneous QoS-sensitive session and ATM VC establishment. Both ST2+ and RSVP are currently proposed for the setup protocol and new setup protocols are likely to be developed in the near future. Therefore, to generalize the discussion, the procedure for the setup protocol in this example is the general connection setup procedure using confirmed service. To implement this signaling procedure, the B-ISDN signaling must include the User-user information element that the capacity is sufficient to forward the setup protocol. Suzuki Expires September, 1998 [Page 7] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 3. Overview of the Generic Identifier and User-to-user Signaling 3.1 Overview of the Generic Identifier The Generic Identifier enables the transfer of identifiers between end-to-end users in the ATM network, and it is defined in the Q.2941 as an optional information element for the Q.2931 and Q.2971 UNI signaling protocol. The SETUP, ALERTING, CONNECT, RELEASE, RELEASE COMPLETE, ADD PARTY, PARTY ALERTING, ADD PARTY ACK, ADD PARTY REJECT, DROP PARTY, and DROP PARTY ACK messages that are transferred between end-to-end users in the ATM network may contain up to three Generic Identifier information elements. The ATM network transfers the Generic Identifier information element transparently if it contains no coding rule errors. Currently ITU-T SG11 recommends the Q.2941 Part 1 (Q.2941.1) that supports the transfer of identifiers for the DSM-CC and H.310. Note that the Generic Identifier for the Internet protocol will be recommended in a new part of the Q.2941 (e.g. Q.2941.2 or Q.2941.3). The format of the Generic Identifier information element specified in the Q.2941.1 is shown in Fig. 3.1. Suzuki Expires September, 1998 [Page 8] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = Generic identifier transport IE (0x7F) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier related standard/application | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier type | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier length | 7 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier value | 8 = = +-----+-----+-----+-----+-----+-----+-----+-----+ = = +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier type | N +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier length | N+1 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier value | N+2 = = +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 3.1: Format of the Generic Identifier information element. The usage of the first 4 octets of fields is specified in section 4 of the Q.2931. The Identifier related standard/application field identifies the standard or application that uses the identifier. A transferred identifier is given by the combination of the Identifier type, length and value fields, and a Generic Identifier information element may contain multiple identifiers. The Identifier type field is currently specified for the Session or Resource. Suzuki Expires September, 1998 [Page 9] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 The maximum length of the Generic Identifier information element is currently 33 octets. See the Q.2941.1 for detailed protocol specifications of the Generic Identifier. 3.2 Overview of the User-to-user Signaling The User-to-user Signaling enables the transfer of information between end-to-end users in the ATM network, and it is defined in Q.2957 and in Q.2971 annex D as an optional information element for the Q.2931 and Q.2971 UNI signaling protocol. The SETUP, ALERTING, CONNECT, RELEASE, RELEASE COMPLETE, PROGRESS, ADD PARTY, PARTY ALERTING, ADD PARTY ACK, ADD PARTY REJECT, DROP PARTY, and DROP PARTY ACK messages that are transferred between end-to-end users in the ATM network may contain a User-user information element. The ATM network transfers the User-user information element transparently if it contains no coding rule errors. From the viewpoint of B-ISDN signaling applications, it seems the Generic Identifier and User-to-user Signaling are similar functions. But their rules for processing exceptions are not completely the same, because their purposes are different. The Generic Identifier is designed for the transfer of identifiers between the c-planes, while the User-to-user Signaling is designed for the transfer of user data via the c-planes. Another difference is that the latter supports interworking with the user-user information element in the Q.931 N- ISDN signaling, but the Generic Identifier does not. The format of the User-user information element is shown in Fig. 3.2. Suzuki Expires September, 1998 [Page 10] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = User-user information element (0x7E) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Protocol discriminator | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | User information | 6 = = | | +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 3.2: Format of the User-user information element. The usage of the first 4 octets of fields is specified in section 4 of the Q.2931. The Protocol discriminator field identifies the upper layer protocol that uses the user-user information. The User information field contains the user-user information to be transferred. The maximum length of the User-user information element is currently 133 octets. See Q.2957 and Q.2971 annex D for detailed protocol specifications of the User-to-user Signaling. Suzuki Expires September, 1998 [Page 11] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 4. Information Field and Protocol Identifier Assignment 4.1 Assignment in the Generic Identifier Information Element 4.1.1 Principle of assignment The information field and protocol identifier assignment principle for the Internet protocol in the Generic Identifier information element is shown in Fig. 4.1. Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = Generic identifier transport IE (0x7F) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier related standard/application | | = Internet protocol/application (TBD) | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier type | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier length | 7 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier value | 8 = = +-----+-----+-----+-----+-----+-----+-----+-----+ = = +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier type | N +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier length | N+1 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier value | N+2 = = +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 4.1: Principle of assignment in the Generic Identifier information element. The Identifier related standard/application field is the Internet protocol/application (TBD). Suzuki Expires September, 1998 [Page 12] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 Assignment of the Identifier type field is as follows. 0x00: Reserved. 0x01: IPv4 session identifier. 0x02: ST2+ session identifier. 0x03: IPv6 session identifier. 0x04-0xFD: Reserved for IANA assignment. 0xFE: Experiment/Vendor specific. 0xFF: Reserved. The Identifier value field is assigned to Internet protocol/application related information that is identified by the Identifier type field. If the Experiment/Vendor specific is specified in the Identifier type field, the first 3 octets in the Identifier value field must contain the Organizationally unique identifier (OUI). Suzuki Expires September, 1998 [Page 13] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 4.1.2 IPv4 session identifier The format of the IPv4 session identifier is shown in Fig. 4.2. Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = Generic identifier transport IE (0x7F) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | | = 16 octets (0x00-10) | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier related standard/application | | = Internet protocol/application (TBD) | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier type | | = IPv4 session identifier (0x01) | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier length | | = 13 octets (0x0D) | 7 +-----+-----+-----+-----+-----+-----+-----+-----+ | Source IPv4 address | 8-11 +-----+-----+-----+-----+-----+-----+-----+-----+ | Destination IPv4 address | 12-15 +-----+-----+-----+-----+-----+-----+-----+-----+ | Protocol | 16 +-----+-----+-----+-----+-----+-----+-----+-----+ | Source Port | 17-18 +-----+-----+-----+-----+-----+-----+-----+-----+ | Destination Port | 19-20 +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 4.2: IPv4 session identifier. The Identifier type field is the IPv4 session identifier (0x01). The Source IPv4 address, Destination IPv4 address, Protocol, Source Port, and Destination Port [5, 7, 8] are assigned in that order to the Identifier value field. The Length of contents of information element and Identifier length are 16 and 13 octets respectively. Suzuki Expires September, 1998 [Page 14] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 4.1.3 ST2+ session identifier The format of the ST2+ session identifier is shown in Fig. 4.3. Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = Generic identifier transport IE (0x7F) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | | = 9 octets (0x00-09) | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier related standard/application | | = Internet protocol/application (TBD) | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier type | | = ST2+ session identifier (0x02) | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier length | | = 6 octets (0x06) | 7 +-----+-----+-----+-----+-----+-----+-----+-----+ | Stream ID (SID) | 8-13 +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 4.3: ST2+ session identifier. The Identifier type field is the ST2+ session identifier (0x02). The Stream ID (SID) [9] is assigned to the Identifier value field. The Length of contents of information element and Identifier length are 9 and 6 octets respectively. Suzuki Expires September, 1998 [Page 15] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 4.1.4 IPv6 session identifier The format of the IPv6 session identifier is shown in Fig. 4.4. Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = Generic identifier transport IE (0x7F) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | | = 40 octets (0x00-28) | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier related standard/application | | = Internet protocol/application (TBD) | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier type | | = IPv6 session identifier (0x03) | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier length | | = 37 octets (0x25) | 7 +-----+-----+-----+-----+-----+-----+-----+-----+ | Source IPv6 address | 8-23 +-----+-----+-----+-----+-----+-----+-----+-----+ | Destination IPv6 address | 24-39 +-----+-----+-----+-----+-----+-----+-----+-----+ | Protocol | 40 +-----+-----+-----+-----+-----+-----+-----+-----+ | Source Port | 41-42 +-----+-----+-----+-----+-----+-----+-----+-----+ | Destination Port | 43-44 +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 4.4: IPv6 session identifier The Identifier type field is the IPv6 session identifier (0x03). The Source IPv6 address, Destination IPv6 address, Protocol, Source Port, and Destination Port [6, 7, 8] are assigned in that order to the Identifier value field. The Length of contents of information element and Identifier length are 40 and 37 octets respectively. Suzuki Expires September, 1998 [Page 16] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 4.1.5 Experiment/Vendor specific The format of the Experiment/Vendor specific is shown in Fig. 4.5. Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = Generic identifier transport IE (0x7F) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier related standard/application | | = Internet protocol/application (TBD) | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier type | | = Experiment/Vendor specific (0xFE) | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | Identifier length | 7 +-----+-----+-----+-----+-----+-----+-----+-----+ | Organizationally unique identifier (OUI) | 8-10 +-----+-----+-----+-----+-----+-----+-----+-----+ | Experiment/Vendor specific info. | 11- = = | | +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 4.5: Experiment/Vendor specific. The Identifier type field is the Experiment/Vendor specific (0xFE). The first 3 octets in the Identifier value field must contain the Organizationally unique identifier (OUI). Suzuki Expires September, 1998 [Page 17] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 4.2 Assignment in the User-user Information Element 4.2.1 Principle of assignment The information field and protocol identifier assignment principle for the Internet protocol in the User-user information element is shown in Fig. 4.6. Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = User-user information element (0x7E) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Protocol discriminator | | = Internet protocol/application (TBD) | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Internet protocol/application identifier | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | Internet protocol/application related info. | 7- = = | | +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 4.6: Principle of assignment in the User-user information element. The Protocol discriminator field is the Internet protocol/application (TBD). In this case, the first 1 octet in the User information field is the Internet protocol/application identifier field. Assignment of the Internet protocol/application identifier field is as follows. 0x00: Reserved. 0x01: MPLS VCID. 0x02-0xFD: Reserved for IANA assignment (Note). 0xFE: Experiment/Vendor specific. 0xFF: Reserved. Suzuki Expires September, 1998 [Page 18] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 Note: Assignment of the Internet protocol/application identifier field for the setup protocol will be specified in a separate document. The field that follows the Internet protocol/application identifier field is assigned to Internet protocol/application related information that is identified by the Internet protocol/application identifier field. If the Experiment/Vendor specific is specified in the Internet protocol/application identifier field, the first 3 octets in the Internet protocol/application related information field must contain the Organizationally unique identifier (OUI). 4.2.2 MPLS VCID The format of the MPLS VCID is shown in Fig. 4.7. Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = User-user information element (0x7E) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Protocol discriminator | | = Internet protocol/application (TBD) | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Internet protocol/application identifier | | = MPLS VCID (0x01) | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | MPLS VCID | 7- = = | | +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 4.7: MPLS VCID. The Internet protocol/application identifier field is the MPLS VCID (0x01). Suzuki Expires September, 1998 [Page 19] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 The MPLS VCID [11] is assigned to the Internet protocol/application related information field. Note: IETF MPLS WG will specify techinical details of the VCID. 4.2.3 Experiment/Vendor specific. The format of the Experiment/Vendor specific is shown in Fig. 4.8. Bits 8 7 6 5 4 3 2 1 Octets +-----+-----+-----+-----+-----+-----+-----+-----+ | Information element identifier | | = User-user information element (0x7E) | 1 +-----+-----+-----+-----+-----+-----+-----+-----+ | 1 | Coding | IE instruction field | | Ext | standard |Flag |Res. | IE action ind. | 2 +-----+-----+-----+-----+-----+-----+-----+-----+ | Length of contents of information element | 3-4 +-----+-----+-----+-----+-----+-----+-----+-----+ | Protocol discriminator | | = Internet protocol/application (TBD) | 5 +-----+-----+-----+-----+-----+-----+-----+-----+ | Internet protocol/application identifier | | = Experiment/Vendor specific (0xFE) | 6 +-----+-----+-----+-----+-----+-----+-----+-----+ | Organizationally unique identifier (OUI) | 7-9 +-----+-----+-----+-----+-----+-----+-----+-----+ | Experiment/Vendor specific info. | 10- = = | | +-----+-----+-----+-----+-----+-----+-----+-----+ Fig. 4.8: Experiment/Vendor specific The Internet protocol/application identifier field is the Experiment/Vendor specific (0xFE). The first 3 octets in the Internet protocol/application related information field must contain the Organizationally unique identifier (OUI). Suzuki Expires September, 1998 [Page 20] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 5. Required Amendments to B-ISDN Signaling The information field and protocol identifier assignment in the Generic Identifier information element and User-user information element, which are described in the previous section, are required for advanced B-ISDN signaling support of the Internet protocol. To enable this support, this section clarifies amendments to the B-ISDN signaling. 5.1 Required Amendments to the Generic Identifier To enable advanced B-ISDN signaling support for the Internet protocol, the following amendments should be applied to the Q.2941.1 Generic Identifier. o Add the Internet protocol/application to the Identifier related standard/application. o Increase the maximum length of the Generic Identifier information element to at least 44 octets. 5.2 Required Amendments to the User-to-user Signaling To enable advanced B-ISDN signaling support for the Internet protocol, the following amendments should be applied to the Q.2957 and Q.2971 annex D User-to-user Signaling. o Add the Internet protocol/application to the Protocol discriminator. o Desirably, increase the maximum length of the User-user information element to sufficiently long, e.g. 262 octets, to forward the setup protocol such as ST2+ and RSVP. This amendment is not applied and remains 133 octets when the User-user information element interworks with the N-ISDN user-user information element. 6. Security Considerations This document specifies the information field and protocol identifier assignment in the Q.2941 Generic Identifier and Q.2957 User-to-user Signaling for the Internet protocol, so these do not weaken the security of the B-ISDN signaling. Suzuki Expires September, 1998 [Page 21] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 In a called party of the B-ISDN signaling, if the incoming SETUP message contains the calling party number and if it is verified and passed by the ATM network or it is provided by the network, then it is feasible to use the calling party number for part of the calling party authentication to strengthen security. References [1] ITU-T, "Broadband Integrated Services Digital Network (B- ISDN)-Digital Subscriber Signaling System No. 2 (DSS 2)-User- Network Interface (UNI) Layer 3 Specification for Basic Call/Connection Control," ITU-T Recommendation Q.2931, September 1995. [2] ITU-T, "Broadband Integrated Services Digital Network (B- ISDN)-Digital Subscriber Signaling System No. 2 (DSS 2)-User- Network Interface Layer 3 Specification for Point-to-Multipoint Call/Connection Control," ITU-T Recommendation Q.2971, October 1995. [3] ITU-T, "Broadband Integrated Services Digital Network (B-ISDN) Digital Subscriber Signaling System No. 2 (DSS 2): Generic Identifier Transport," Draft ITU-T New Recommendation Q.2941.1, September 1997. [4] ITU-T, "Stage 3 Description for Additional Information Transfer Supplementary Service Using B-ISDN Digital Subscriber Signaling System No. 2 (DSS 2)-Basic Call Clause 1-User-to-User Signalling (UUS)," ITU-T Recommendation Q.2957, February 1995. [5] J. Postel Ed., "Internet Protocol," RFC 791, September 1981. [6] S. Deering and R. Hinden, "Internet Protocol, Version 6 (IPv6) Specification," Internet Draft, July 1997,. [7] J. Postel, "User Datagram Protocol," RFC 768, August 1980. [8] J. Postel Ed., "Transmission Control Protocol," RFC 793, September 1981. [9] L. Delgrossi and L. Berger, Ed., "Internet Stream Protocol Version 2 (ST2) Protocol Specification - Version ST2+," RFC 1819, August 1995. [10] R. Braden Ed., "Resource ReSerVation Protocol (RSVP)-Version 1 Functional Specification," RFC 2205, September 1997. Suzuki Expires September, 1998 [Page 22] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 [11] K. Nagami, N. Demizu, H. Esaki, and P. Doolan, "VCID Notification over ATM link," Internet Draft, March 1998, . [12] P. Newman, T. Lyon, and G. Minshall, "Flow Labelled IP: A Connectionless Approach to ATM," Proc. IEEE Infocom, March 1996. [13] S. Damaskos and A. Gavras, "Connection Oriented Protocols over ATM: A case study," Proc. SPIE, Vol. 2188, pp.226-278, February 1994. [14] ITU-T, "Integrated Services Digital Network (ISDN) Overall Network Aspects and Functions ISDN Protocol Reference Model," ITU-T Recommendation I.320, November 1993. [15] ITU-T, "Digital Subscriber Signaling System No. 1 (DSS 1) Specification of a Synchronization and Coordination Function for the Provision of the OSI Connection-mode Network Service in an ISDN Environment," ITU-T Recommendation Q.923, February 1995. [16] K. Kitami, "Expected Direction for B-ISDN & Multimedia Signaling in the Areas for Enhancements, focusing on the support of the Internet," ITU-T SG11 Delayed Contribution D.398, September 1997, (http://www.nal.ecl.net/SG11WP1/itu-t-sg11-del-contrib- d398.pdf). [17] K. Kitami, "Proposed Direction for B-ISDN & Multimedia Signaling," ITU-T SG11 Delayed Contribution D.647, January 1998, (http://www.nal.ecl.net/SG11WP1/itu-t-sg11-del-contrib-d647.ps). [18] K. Mainwaring, "Report of ad-hoc group on signaling protocol support for IP over ATM SVCs," ITU-T SG11 Temporary Document TD. 1/11-77 Rev 1, January 1998, (http://www.nal.ecl.net/SG11WP1/itu- t-sg11-tmp-doc-td77r1.ps, itu-t-sg11-tmp-doc-td77r1a.ps). Acknowledgments I would like to thank Kenichi Kitami of the NTT Network Innovation Planning and Promotion Dept., who is also the chair of ITU-T SG11 WP1, Shinichi Kuribayashi of the NTT Business Communications Hqs., Hiroshi Yao and Takumi Ohba of the NTT Network Service Systems Labs., and Noriyuki Takahashi of the NTT Multimedia Networks Labs. for their valuable comments and discussions. Suzuki Expires September, 1998 [Page 23] INTERNET DRAFT draft-suzuki-git-uus-assignment-02.txt March, 1998 And I would also like to thank the active members of IETF, ITU-T, and ATM Forum, especially Joel Halpern of Newbridge Networks, Andrew Malis of Ascend Communications, Rao Cherukuri of IBM, Rajiv Kapoor of AT&T, Greg Ratta of Lucent, Hiroshi Esaki and Kenichi Nagami of Toshiba, and Noritoshi Demizu of Sony CSL/NAIST for their valuable comments and suggestions. Also this specification is based on various discussions during the ST2+ over ATM project at the NTT Multimedia Joint Project with NACSIS. I would like to thank Professor Shoichiro Asano of the National Center for Science Information Systems for his invaluable advice in this area. Author's Address Muneyoshi Suzuki NTT Multimedia Networks Laboratories 3-9-11, Midori-cho Musashino-shi, Tokyo 180, Japan Phone: +81-422-59-2119 Fax: +81-422-59-3203 EMail: suzuki@nal.ecl.net Suzuki Expires September, 1998 [Page 24]