Internet Engineering Task Force                             Alain Durand
INTERNET-DRAFT                                                 Jim Paugh
July 20, 2001                                      SUN Microsystems, Inc
Expires January 21, 2001







                   MIME TYPE definition for tunnels
            <draft-durand-ngtrans-tunnel-mime-type-03.txt>





Status of Memo

    This document is an Internet-Draft and is in full conformance with
    all provisions of Section 10 of RFC2026.
    This document is an Internet-Draft. Internet-Drafts are working
    documents of the Internet Engineering Task Force (IETF), its areas,
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Abstract

    Tunnels are very common in the Internet. They are often
    used to deploy new technologies such as multicast or IPv6 when the
    underlying infrastructure is not ready to natively support
    those new protocols. Virtual Private Network are also often build
    using IP in IP tunnels.
    This document describe a MIME type that provide configuration
    information for tunnels.


1. Introduction

    Managing IP in IP tunnels can be a complex task and various
    approaches have been developed to assist network administrators.
    In the context of IPv6 transition, the tunnel broker model [BROKER]
    has been developed for that very purpose and highlighted the need
    for a formal description of IPv6 in IPv4 tunnels.
    However, such a description can be made more generic and provide
    information about almost any kind of tunnels.

2. Related work

    [RADTUN] describe tunnel attributes in RADIUS format.


3. Tunnel management

    Tools and/or protocols to do the actual tunnel management are
    out of the scope of this document.


4. MIME type definition

    In conformance with [MIME], the MIME object to describe
    tunnels is defined in the IETF tree as a subtype
    of the "Application" MIME type.

    The proposed subtype is "tunnel".

    The tunnel described by this object is a unidirectional tunnel
    from host SRC to host DST.


4.1 Parameters


    Mandatory parameters: none
    Optional parameters: none


4.2 Mandatory MIME headers


4.2.1 Encapsulation type


    header name: encapsulation-type
    header type: Integer
    possible values:


    Tunnel encapsulation types values are taken from [RADTUN].


    1      Point-to-Point Tunneling Protocol [PPTP]
    2      Layer Two Forwarding [L2F]
    3      Layer Two Tunneling Protocol [L2TP]
    4      Ascend Tunnel Management Protocol [ATMP]
    5      Virtual Tunneling Protocol (VTP)
    6      IP Authentication Header in the Tunnel-mode (AH) [IPsec]
    7      IP-in-IP Encapsulation [IP-IP]
    8      Minimal IP-in-IP Encapsulation [MIN-IP]
    9      IP Encapsulating Security Payload in the Tunnel-mode [ESP]
    10     Generic Route Encapsulation [GRE]
    11     Bay Dial Virtual Services (DVS)
    12     IP-in-IP Tunneling [IPinIP]


4.2.2 Tunnel inner medium type


    header name: inner-medium
    header type: Integer
    possible values:


    Tunnel inner medium type values are taken from [NUMBER].
    A short exerpt is:


    1      IPv4 (IP version 4)
    2      IPv6 (IP version 6)
    3      NSAP
    4      HDLC (8-bit multidrop)
    5      BBN 1822
    6      802 (includes all 802 media plus Ethernet "canonical format")
    7      E.163 (POTS)
    8      E.164 (SMDS, Frame Relay, ATM)
    9      F.69 (Telex)
    10     X.121 (X.25, Frame Relay)
    11     IPX
    12     Appletalk
    13     Decnet IV
    14     Banyan Vines
    15     E.164 with NSAP format subaddress



4.2.3 Tunnel outer medium type


    header name: outer-medium
    header type: Integer
    possible values:


    Tunnel outer medium type values are taken from [NUMBER].
    A short exerpt is:


    1      IPv4 (IP version 4)
    2      IPv6 (IP version 6)
    3      NSAP
    4      HDLC (8-bit multidrop)
    5      BBN 1822
    6      802 (includes all 802 media plus Ethernet "canonical format")
    7      E.163 (POTS)
    8      E.164 (SMDS, Frame Relay, ATM)
    9      F.69 (Telex)
    10     X.121 (X.25, Frame Relay)
    11     IPX
    12     Appletalk
    13     Decnet IV
    14     Banyan Vines
    15     E.164 with NSAP format subaddress




4.2.4 Inner source address

    header name: inner-src
    header type: string
    possible values: any textual representation of an
                     address enclosed in square brackets.

    Inner source address is the source address in the inner
    header of any packet originated from host SRC through the tunnel.

4.2.4 Outer source address

    header name: outer-src
    header type: string
    possible values: any textual representation of an
                     address enclosed in square brackets.

    Outer source address is the source address in the outer
    header of any packet originated from host SRC through the tunnel.

4.2.5 Inner destination address

    header name: inner-dst
    header type: string
    possible values: any textual representation of an
                     address enclosed in square brackets.

    Inner destination address is the destination address in the inner
    header of any packet originated from host SRC through the tunnel.

4.2.6 Outer destination address

    header name: outer-dst
    header type: string
    possible values: any textual representation of an
                     address enclosed in square brackets.


    Outer destination address is the destination address in the outer
    header of any packet originated from host SRC through the tunnel.


4.3 Optional MIME headers

4.3.1 Inner addresses lifetime

    header name: inner-lifetime
    header type: Integer
    possible values: the lifetime in second of the inner pair
                     of addresses, source and destination.


    A value of zero means infinite lifetime.

4.3.2 Outer addresses lifetime

    header name: outer-lifetime
    header type: Integer
    possible values: the lifetime in second of the outer pair
                     of addresses, source and destination.


    A value of zero means infinite lifetime.

4.3.3 E-mail contact for SRC

    header name: src-email
    header type: string
    possible values: any valid email address, according to [MAIL].

    This is the administrative contact email address for host SRC.
    The exact semantic of this parameter is beyond the scope of
    this document.

4.3.4 E-mail contact for DST

    header name: dst-email
    header type: string
    possible values: any valid email address, according to [MAIL].

    This is the administrative contact email address for host DST.
    The exact semantic of this parameter is beyond the scope of
    this document.


5. Example


    The following will describe and IPv6 in IPv4 tunnel
        between SRC host A and DST host B. The lifetime of
        the tunnel is 1 hour. Alain Durand is the contact
        for host A and Jim Paugh is the contact for host B.

        Host A IPv4 address is 100.100.100.100
        Host A IPv6 address is 3ffe:ffff:ffff:1:0:0:0:A
        Host B IPv4 address is 200.200.200.200
        Host B IPv6 address is 3ffe:ffff:ffff:2:0:0:0:B

    The mime object is:

    Mime-version: 1.0
        Content-type: Application/tunnel
        encapsulation-type: 7
        inner-medium: 2
        outer-medium: 1
        inner-src: 3ffe:ffff:ffff:1:0:0:0:A
        outer-src: 100.100.100.100
        inner-dst: 3ffe:ffff:ffff:2:0:0:0:B
        outer-dst: 200.200.200.200
        inner-lifetime: 3600
    src-email: Alain.Durand@sun.com
        dst-email: Jim.Paugh@sun.com




6. IANA registration


    To: ietf-types@iana.org
    Subject: Registration of MIME media type application/tunnel


    MIME media type name: application


    MIME subtype name: tunnel


    Required parameters: none


    Optional parameters: none


    Encoding considerations: None


    Required headers: encapsulation-type,
                      inner-medium, outer-medium,
                      inner-src, outer-src,
                      inner-dst, outer-dst


    Optional headers: inner-lifetime, outer-lifetime,
                      src-email, dst-email


    Security considerations:


    The information contained in this MIME type may be used by
    application to configured tunnel. Inaccurate information can
    introduce all kind of security hazards, thus it is of the utmost
    importance that these information are transferred over a secure
    channel, that their originator is authenticated and that they are
    guaranteed not to be corrupted.


    Interoperability considerations:


    The mandatory parameters are necessary to guarantee interoperability.


    Published specification: none


    Applications which use this media type:
    Tunnel Brokers, tunnel servers,
    tunnel clients, any database storing tunnel information.


    Additional information:


      Magic number(s): none
      File extension(s): none
      Macintosh File Type Code(s): none


    Person & email address to contact for further information:


    Alain Durand           Jim Paugh
    Alain.Durand@sun.com   Jim.Paugh@sun.com


    Intended usage: COMMON


    Author/Change controller: Alain.Durand@sun.com, Jim.Paugh@sun.com




7. Security Considerations


    The information contained in this MIME type may be used by
    application to configured tunnel. Inaccurate information can
    introduce all kind of security hazards, thus it is of the utmost
    importance that these information are transferred over a secure
    channel, that their originator is authenticated and that they are
    guaranteed not to be corrupted. The exact procedure/protocols to be
    used for this purpose is out of the scope of this document.



8. References

[BROKER] Durand, A., Fasano, P., Guardini, I., Lento, D.,
         IPv6 Tunnel Broker,
         RFC3052, February 2001


[MIME]   Freed, N., Borenstein, N.,
         "Multipurpose Internet Mail Extensions
         (MIME) Part four: MIME registration procedure, RFC2048,
         November 1996.


[RADTUN] Zorn, G., Leifer, D., Rubens, A., Shriver, J., Holdrege, M.,
         Goyret, I., RADIUS Attributes for Tunnel Protocol Support,
         RFC2868, June 2000.


[MAIL]   Crocker, D.,
         Standard for the format of ARPA Internet text messages,
         RFC822, August 1982.


[NUMBER] Reynolds, J. and J. Postel,
         "Assigned Numbers", STD 2, RFC 1700,
         October 1994.


[PPTP]   Hamzeh, K., Pall, G., Verthein, W., Taarud,
         J., Little, W. and G. Zorn,
         "Point-to-Point Tunneling Protocol (PPTP)",
         RFC 2637, July 1999.


[L2F]    Valencia, A., Littlewood, M. and T. Kolar, T.,
         "Cisco Layer Two Forwarding (Protocol) 'L2F'",
         RFC2341, May 1998.


[L2TP]   Townsley, W., Valencia, A., Rubens, A., Pall,
         G., Zorn, G. and B. Palter,
         "Layer Two Tunnelling Protocol (L2TP)",
         RFC2661, August 1999.


[ATMP]   Hamzeh, K., "Ascend Tunnel Management Protocol - ATMP",
         RFC2107, February 1997.


[IPsec]  Kent, S. and R. Atkinson,
         "Security Architecture for the Internet Protocol",
         RFC2401, November 1998.


[IP-IP]  Perkins, C., "IP Encapsulation within IP",
         RFC2003, October 1996.


[Min-IP] Perkins, C., "Minimal Encapsulation within IP",
         RFC2004, October 1996.


[ESP]    Atkinson, R., "IP Encapsulating Security Payload (ESP)",
         RFC1827, August 1995.


[GRE]    Hanks, S., Li, T., Farinacci, D. and P. Traina,
         "Generic Routing Encapsulation (GRE)",
         RFC 1701, October 1994.


[INinIP] Simpson, W., "IP in IP Tunneling",
         RFC1853, October 1995.





9. Author's addresses

    Alain Durand
    SUN Microsystems, Inc
    901 San Antonio Road
    MPK17-202
    Palo Alto, CA 94303-4900
    USA
    Mail: Alain.Durand@sun.com


    Jim Paugh
    SUN Microsystems, Inc
    901 San Antonio Road
    MPK17-203
    Palo Alto, CA 94303-4900
    USA
    Mail: Jim.Paugh@sun.com