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rfc:rfc1707

Network Working Group: M. McGovern Request for Comments: 1707 Sunspot Graphics Category: Informational R. Ullmann

                                         Lotus Development Corporation
                                                          October 1994
            CATNIP: Common Architecture for the Internet

Status of this Memo

 This memo provides information for the Internet community.  This memo
 does not specify an Internet standard of any kind.  Distribution of
 this memo is unlimited.

Abstract

 This document was submitted to the IETF IPng area in response to RFC
 1550  Publication of this document does not imply acceptance by the
 IPng area of any ideas expressed within.  Comments should be
 submitted to the big-internet@munnari.oz.au mailing list.

Executive Summary

 This paper describes a common architecture for the network layer
 protocol. The Common Architecture for Next Generation Internet
 Protocol (CATNIP) provides a compressed form of the existing network
 layer protocols. Each compression is defined so that the resulting
 network protocol data units are identical in format. The fixed part
 of the compressed format is 16 bytes in length, and may often be the
 only part transmitted on the subnetwork.
 With some attention paid to details, it is possible for a transport
 layer protocol (such as TCP) to operate properly with one end system
 using one network layer (e.g. IP version 4) and the other using some
 other network protocol, such as CLNP. Using the CATNIP definitions,
 all the existing transport layer protocols used on connectionless
 network services will operate over any existing network layer
 protocol.
 The CATNIP uses cache handles to provide both rapid identification of
 the next hop in high performance routing as well as abbreviation of
 the network header by permitting the addresses to be omitted when a
 valid cache handle is available. The fixed part of the network layer
 header carries the cache handles.

McGovern & Ullmann [Page 1] RFC 1707 CATNIP October 1994

 The cache handles are either provided by feedback from the downstream
 router in response to offered traffic, or explicitly provided as part
 of the establishment of a circuit or flow through the network. When
 used for flows, the handle is the locally significant flow
 identifier.
 When used for circuits, the handle is the layer 3 peer-to-peer
 logical channel identifier, and permits a full implementation of
 network-layer connection-oriented service if the routers along the
 path provide sufficient features. At the same time, the packet format
 of the connectionless service is retained, and hop by hop fully
 addressed datagrams can be used at the same time. Any intermediate
 model between the connection oriented and the connectionless service
 can thus be provided over cooperating routers.

CATNIP Objectives

 The first objective of the CATNIP is a practical recognition of the
 existing state of internetworking, and an understanding that any
 approach must encompass the entire problem. While it is common in the
 IP Internet to dismiss the ISO with various amusing phrases, it is
 hardly realistic. As the Internet moves into the realm of providing
 real commercial infrastructure, for telephone, cable television, and
 the myriad other mundane uses, compliance with international
 standards is an imperative.
 The argument that the IETF need not (or should not) follow existing
 ISO standards will not hold. The ISO is the legal standards
 organization for the planet. Every other industry develops and
 follows ISO standards. There is (no longer) anything special about
 computer software or data networking.
 ISO convergence is both necessary and sufficient to gain
 international acceptance and deployment of IPng. Non-convergence will
 effectively preclude deployment.
 The CATNIP integrates CLNP, IP, and IPX. The CATNIP design provides
 for any of the transport layer protocols in use, for example TP4,
 CLTP, TCP, UDP, IPX and SPX to run over any of the network layer
 protocol formats: CLNP, IP (version 4), IPX, and the CATNIP.

Incremental Infrastructure Deployment

 The best use of the CATNIP is to begin to build a common Internet
 infrastructure. The routers and other components of the common system
 are able to use a single consistent addressing method, and common
 terms of reference for other aspects of the system.

McGovern & Ullmann [Page 2] RFC 1707 CATNIP October 1994

 The CATNIP is designed to be incrementally deployable in the strong
 sense: you can plop a CATNIP system down in place of any existing
 network component and continue to operate normally with no
 reconfiguration.  (Note: not "just a little". None at all. The number
 of "little changes" suggested by some proposals, and the utterly
 enormous amount of documentation, training, and administrative effort
 then required, astounds the present authors.) The vendors do all of
 the work.
 There are also no external requirements; no "border routers", no
 requirement that administrators apply specific restrictions to their
 network designs, define special tables, or add things to the DNS.
 When the end users and administrators fully understand the combined
 system, they will want to operate differently, but in no case will
 they be forced. Not even in small ways. Networks and end user
 organizations operate under sufficient constraints on deployment of
 systems anyway; they do not need a new network architecture adding to
 the difficulty.
 Typically deployment will occur as part of normal upgrade revisions
 of software, and due to the "swamping" of the existing base as the
 network grows. (When the Internet grows by a factor of 5, at least
 80% will then be "new" systems.) The users of the network may then
 take advantage of the new capabilities. Some of the performance
 improvements will be automatic, others may require some
 administrative understanding to get to the best performance level.
 The CATNIP definitions provide stateless translation of network
 datagrams to and from CATNIP and, by implication, directly between
 the other network layer protocols. A CATNIP-capable system
 implementing the full set of definitions can interoperate with any
 existing protocol. Various subsets of the full capability may be
 provided by some vendors.

No Address Translation

 Note that there is no "address translation" in the CATNIP
 specification.  (While it may seem odd to state a negative objective,
 this is worth saying as people seem to assume the opposite.) There
 are no "mapping tables", no magic ways of digging translations out of
 the DNS or X.500, no routers looking up translations or asking other
 systems for them.
 Addresses are modified with a simple algorithmic mapping, a mapping
 that is no more than using specific prefixes for IP and IPX
 addresses. Not a large set of prefixes; one prefix. The entire
 existing IP version 4 network is mapped with one prefix and the IPX
 global network with one other prefix. (The IP mapping does provide

McGovern & Ullmann [Page 3] RFC 1707 CATNIP October 1994

 for future assignment of other IANA/IPv4 domains that are disjoint
 from the existing one.)
 This means that there is no immediate effect on addresses embedded in
 higher level protocols.
 Higher level protocols not using the full form (those native to IP
 and IPX) will eventually be extended to use the full addressing to
 extend their usability over all of the network layers.

No Legacy Systems

 The CATNIP leaves no systems behind: with no reconfiguration, any
 system presently capable of IP, CLNP, or IPX retains at least the
 connectivity it has now.  With some administrative changes (such as
 assigning IPX domain addresses to some CLNP hosts for example) on
 other systems, unmodified systems may gain significant connectivity.
 IPX systems with registered network numbers may gain the most.

Limited Scope

 The CATNIP defines a common network layer packet format and basic
 architecture. It intentionally does not specify ES-IS methods,
 routing, naming systems, autoconfiguration and other subjects not
 part of the core Internet wide architecture. The related problems and
 their (many) solutions are not within the scope of the specification
 of the basic common network layer.

Existing Addresses and Network Numbers

 The Internet's version 4 numbering system has proven to be very
 flexible, (mostly) expandable, and simple.  In short: it works.
 However, there are two problems. Neither was considered serious when
 the CATNIP was first developed in 1988 and 1989, but both are now of
 major concern:
 o The division into network, and then subnet, is insufficient.
   Almost all sites need a network assignment large enough to
   subnet. At the top of the hierarchy, there is a need to assign
   administrative domains.
 o As bit-packing is done to accomplish the desired network
   structure, the 32-bit limit causes more and more aggravation.
 Another major addressing system used in open internetworking is the
 OSI method of specifying Network Service Access Points (NSAPs). The
 NSAP consists of an authority and format identifier, a number

McGovern & Ullmann [Page 4] RFC 1707 CATNIP October 1994

 assigned to that authority, an address assigned by that authority,
 and a selector identifying the next layer (transport layer) protocol.
 This is actually a general multi-level hierarchy, often obscured by
 the details of specific profiles. (For example, CLNP doesn't specify
 20 octet NSAPs, it allows any length. But various GOSIPs profile the
 NSAP as 20 octets, and IS-IS makes specific assumptions about the
 last 1-8 octets. And so on.)
 The NSAP does not directly correspond to an IP address, as the
 selector in IP is separate from the address. The concept that does
 correspond is the NSAP less the selector, called the Network Entity
 Title or NET. (An unfortunate acronym, but one we will use to avoid
 repeating the full term.) The usual definition of NET is an NSAP with
 the selector set to 0; the NET used here omits the 0 selector.
 There is also a network numbering system used by IPX, a product of
 Novell, Inc. (referred to from here on as Novell) and other vendors
 making compatible software. While IPX is not yet well connected into
 a global network, it has a larger installed base than either of the
 other network layers.

Network Layer Address

 The network layer address looks like:
    +----------+----------+---------------+---------------+
    |  length  |   AFI    |  IDI ...      | DSP ...       |
    +----------+----------+---------------+---------------+
 The fields are named in the usual OSI terminology although that leads
 to an oversupply of acronyms. Here are more detailed descriptions of
 each field:
 length: the number of bytes (octets) in the remainder of the
         address.
 AFI: the Authority and Format Identifier. A single byte
      value, from a set of well-known values registered by
      ISO, that determines the semantics of the IDI field
 IDI: the Initial Domain Identifier, a number assigned by the
      authority named by the AFI, formatted according to the
      semantics implied by the AFI, that determines the
      authority for the remainder of the address.
 DSP: Domain Specific Part, an address assigned by the
      authority identified by the value of the IDI.

McGovern & Ullmann [Page 5] RFC 1707 CATNIP October 1994

 Note that there are several levels of authority. ISO, for example,
 identifies (with the AFI) a set of numbering authorities (like X.121,
 the numbering plan for the PSPDN, or E.164, the numbering plan for
 the telephone system). Each authority numbers a set of organizations
 or individuals or other entities. (For example, E.164 assigns
 16172477959 to me as a telephone subscriber.)
 The entity then is the authority for the remainder of the address. I
 can do what I please with the addresses starting with (AFI=E.164)
 (IDI=16172477959). Note that this is a delegation of authority, and
 not an embedding of a data-link address (the telephone number) in a
 network layer address. The actual routing of the network layer
 address has nothing to do with the authority numbering.
 The domain-specific part is variable length, and can be allocated in
 whatever way the authority identified by the AFI+IDI desires.

Network Layer Datagram

 The common architecture format for network layer datagrams is
 described below. The design is a balance between use on high
 performance networks and routers, and a desire to minimize the number
 of bits in the fixed header. Using the current state of processor
 technology as a reference, the fixed header is all loaded into CPU
 registers on the first memory cycle, and it all fits within the
 operation bandwidth. The header leaves the remaining data aligned on
 the header size (128 bits); with 64 bit addresses present and no
 options it leaves the transport header 256 bit aligned.
 On very slow and low performance networks, the fixed header is still
 fairly small, and could be further compressed by methods similar to
 those used with IP version 4 on links that consider every bit
 precious. In between, it fits nicely into ATM cells and radio
 packets, leaving sufficient space for the transport header and
 application data.

McGovern & Ullmann [Page 6] RFC 1707 CATNIP October 1994

    +---------------+---------------+-+-+-+-+-+-+-+-+---------------+
    |   NLPID (70)  |  Header Size  |D|S|R|M|E| MBZ | Time to Live  |
    +---------------+---------------+-+-+-+-+-+-+-+-+---------------+
    |                 Forward Cache Identifier                      |
    +---------------------------------------------------------------+
    |                      Datagram Length                          |
    +---------------------------------------------------------------+
    |     Transport Protocol        |          Checksum             |
    +---------------------------------------------------------------+
    |               Destination Address ...                         |
    +---------------------------------------------------------------+
    |               Source Address ...                              |
    +---------------------------------------------------------------+
    |               Options ...                                     |
    +---------------------------------------------------------------+
NLPID: The first byte (the network layer protocol identifier in OSI)
       is an 8 bit constant 70 (hex). This corresponds to Internet
       Version 7.
Header Length: The header length is a 8-bit count of the number of
       32-bit words in the header. This allows the header to
       be up to 1020 bytes in length.
Flags: This byte is a small set of flags determining the datagram
       header format and the processing semantics. The last three bits
       are reserved, and must be set to zero. (Note that the
       corresponding bits in CLNP version 1 are 001, since this byte
       is the version field. This may be useful.)
Destination Address Omitted: When the destination address omitted
       (DAO) flag is zero, the destination address is present as shown
       in the datagram format diagram. When a datagram is sent with
       an FCI that identifies the destination and the DAO flag is
       set, the address does not appear in the datagram.
Source Address Omitted: The source address omitted (SAO) flag is zero
       when the source address is present in the datagram. When
       datagram is sent with an FCI that identifies the source and the
       SAO flag is set, the source address is omitted from the
       datagram.
Report Fragmentation Done: When this bit (RFD) is set, an intermediate
       router that fragments the datagram (because it is larger than
       the next subnetwork MTU) should report the event with an ICMP
       Datagram Too Big message. (Unlike IP version 4, which uses DF
       for MTU discovery, the RFD flag allows the fragmented datagram

McGovern & Ullmann [Page 7] RFC 1707 CATNIP October 1994

       to be delivered.)
Mandatory Router Option: The mandatory router option (MRO) flag
       indicates that routers forwarding the datagram must look at the
       network header options.  If not set, an intermediate router
       should not look at the header options.  (But it may anyway;
       this is a necessary consequence of transparent network layer
       translation, which may occur anywhere.)
       The destination host, or an intermediate router doing
       translation, must look at the header options regardless of
       the setting of the MRO flag.
       A router doing fragmentation will normally only use the F
       flag in options to determine whether options should be copied
       within the fragmentation code path. (It might also recognize
       and elide null options.) If the MRO flag is not set, the router
       may not act on an option even though it copies it properly
       during fragmentation.
       If there are no options present, MRO should always be zero, so
       that routers can follow the no-option profile path in their
       implementation.  (Remember that the presence of options cannot
       be divided from the header length, since the addresses are
       variable length.)
Error Report Suppression: The ERS flag is set to suppress the sending
       of error reports by any system (whether host or router)
       receiving or forwarding the datagram. The system may log the
       error, increment network management counters, and take any
       similar action, but ICMP error messages or CNLP error reports
       must not be sent.
       The ERS flag is normally set on ICMP messages and other network
       layer error reports. It does not suppress the normal response
       to ICMP queries or similar network layer queries (CNLP echo
       request).
       If both the RFD and ERS flags are set, the fragmentation report
       is sent.  (This definition allows a larger range of
       possibilities than simply over-riding the RFD flag would; a
       sender not desiring this behavior can see to it that RFD is
       clear.)
Time To Live: The time to live is a 8-bit count, nominally in seconds.
       Each hop is required to decrement TTL by at least one. A hop
       that holds a datagram for an unusual amount of time (more than
       2 seconds, a typical example being a wait for a subnetwork

McGovern & Ullmann [Page 8] RFC 1707 CATNIP October 1994

       connection establishment) should subtract the entire waiting
       time in seconds (rounded upward) from the TTL.
Forward Cache Identifier: Each datagram carries a 32 bit field, called
       "forward cache identifier", that is updated (if the information
       is available) at each hop. This field's value is derived from
       ICMP messages sent back by the next hop router, a routing
       protocol (e.g., RAP), or some other method. The FCI is used to
       expedite routing decisions by preserving knowledge where
       possible between consecutive routers. It can also be used to
       make datagrams stay within reserved flows, circuits, and mobile
       host tunnels. If an FCI is not available, this field must be
       zero, the SAO and DAO flags must be clear, and both destination
       and source addresses must appear in the datagram.
Datagram Length: The 32-bit length of the entire datagram in octets.
       A datagram can therefore be up to 4294967295 bytes in overall
       length.  Particular networks normally impose lower limits.
Transport Protocol: The transport layer protocol. For example, TCP is
       6.
Checksum: The checksum is a 16-bit checksum of the entire header,
       using the familiar algorithm used in IP version 4.
Destination: The destination address, a count byte followed by the
       destination NSAP with the zero selector omitted. This field is
       present only if the DAO flag is zero. If the count field is not
       3 modulo 4 (the destination is not an integral multiple of
       32-bit words) zero bytes are added to pad to the next multiple
       of 32 bits. These pad bytes are not required to be ignored:
       routers may rely on them being zero.
Source: The source address, in the same format as the destination.
       Present only if the SAO flag is zero. The source is padded in
       the same way as destination to arrive at a 32-bit boundary.
Options: Options may follow. They are variable length, and always
       32-bit aligned. If the MRO flag in the header is not set,
       routers will usually not look at or take action on any option,
       regardless of the setting of the class field.

Multicasting

 The multicast-enable option permits multicast forwarding of the
 CATNIP datagram on subnetworks that directly support media layer
 multicasting. This is a vanishing species, even in 10 Mbps Ethernet,
 given the increasing prevalence of switching hubs. It also (perhaps

McGovern & Ullmann [Page 9] RFC 1707 CATNIP October 1994

 more usefully) permits a router to forward the datagram on multiple
 paths when a multicast routing algorithm has established such paths.
 There is no option data.
 Note that there is no special address space for multicasting in the
 CATNIP. Multicast destination addresses can be allocated anywhere by
 any administration or authority. This supports a number of differing
 models of addressing. It does require that the transport layer
 protocol know that the destination is multicast; this is desirable in
 any case. (For example, the transport will probably want to set the
 ERS flag.)
 On an IEEE 802.x (ISO 8802.x) type media, the last 23 bits of the
 address (not including the 0 selector) are used in combination with
 the multicast group address assigned to the Internet to form the
 media address when forwarding a datagram with the multicast enable
 option from a router to an attached network provided that the
 datagram was not received on that network with either multicast or
 broadcast media addressing. A host may send a multicast datagram
 either to the media multicast address (the IP catenet model,) or
 media unicast to a router which is expected to repeat it to the
 multicast address within the entire level I area or to repeat copies
 to the appropriate end systems within the area on non-broadcast media
 (the more general CLNP model.)

Network Layer Translation

 The objective of translation is to be able to upgrade systems, both
 hosts and routers, in whatever order desired by their owners.
 Organizations must be able to upgrade any given system without
 reconfiguration or modification of any other, and existing hosts must
 be able to interoperate essentially forever. (Non-CATNIP routers will
 probably be effectively eliminated at some point, except where they
 exist in their own remote or isolated corners.)
 Each CATNIP system, whether host or router, must be able to recognize
 adjacent systems in the topology that are (only) IP version 4, CLNP,
 or IPX and call the appropriate translation routine just before
 sending the datagram.

OSI CNLP

 The translation between CLNP and the CATNIP compressed form of the
 datagrams is the simplest case for CATNIP, since the addresses are
 the same and need not be extended. The resulting CATNIP datagrams may
 omit the source and destination addresses as explained previously,
 and may be mixed with uncompressed datagrams on the same subnetwork
 link. Alternatively, a subnetwork may operate entirely in the CATNIP,

McGovern & Ullmann [Page 10] RFC 1707 CATNIP October 1994

 converting all transit traffic to CATNIP datagrams, even if FCIs that
 would make the compression effective are not available.
 Similarly, all network datagram formats with CATNIP mappings may be
 compressed into the common form, providing a uniform transit network
 service, with common routing protocols (such as IS-IS).

Internet Protocol

 All existing version 4 numbers are defined as belonging to the
 Internet by using a new AFI, to be assigned to IANA by the ISO. This
 document uses 192 at present for clarity in examples; it is to be
 replaced with the assigned AFI. The AFI specifies that the IDI is two
 bytes long, containing an administrative domain number.
 The AD (Administrative Domain), identifies an administration which
 may be an international authority (such as the existing InterNIC), a
 national administration, or a large multi-organization (e.g., a
 government). The idea is that there should not be more than a few
 hundred of these at first, and eventually thousands or tens of
 thousands at most.
 AD numbers are assigned by IANA. Initially, the only assignment is
 the number 0.0, assigned to the InterNIC, encompassing the entire
 existing version 4 Internet.
 The mapping from/to version 4 IP addresses:
    +----------+----------+---------------+---------------------+
    |  length  |   AFI    |  IDI ...      | DSP ...             |
    +----------+----------+---------------+---------------------+
    |     7    |   192    |  AD number    | version 4 address   |
    +----------+----------+---------------+---------------------+
 While the address (DSP) is initially always the 4 byte, version 4
 address, it can be extended to arbitrary levels of subnetting within
 the existing Internet numbering plan. Hosts with DSPs longer than 4
 bytes will not be able to interoperate with version 4 hosts.

Novell IPX

 The Internetwork Packet Exchange protocol, developed by Novell based
 on the XNS protocol (Xerox Network System) has many of the same
 capabilities as the Internet and OSI protocols. At first look, it
 appears to confuse the network and transport layers, as IPX includes
 both the network layer service and the user datagram service of the
 transport layer, while SPX (sequenced packet exchange) includes the
 IPX network layer and provides service similar to TCP or TP4. This

McGovern & Ullmann [Page 11] RFC 1707 CATNIP October 1994

 turns out to be mostly a matter of the naming and ordering of fields
 in the packets, rather than any architectural difference.
 IPX uses a 32-bit LAN network number, implicitly concatenated with
 the 48-bit MAC layer address to form an Internet address. Initially,
 the network numbers were not assigned by any central authority, and
 thus were not useful for inter-organizational traffic without
 substantial prior arrangement. There is now an authority established
 by Novell to assign unique 32-bit numbers and blocks of numbers to
 organizations that desire inter-organization networking with the IPX
 protocol.
 The Novell/IPX numbering plan uses an ICD, to be assigned, to
 designate an address as an IPX address. This means Novell uses the
 authority (AFI=47)(ICD=Novell) and delegates assignments of the
 following 32 bits.
 An IPX address in the common form looks like:
    +----------+----------+---------------+---------------------+
    |  length  |   AFI    |  IDI ...      | DSP ...             |
    +----------+----------+---------------+---------------------+
    |    13    | 47 (hex) |  Novell ICD   | network+MAC address |
    +----------+----------+---------------+---------------------+
 This will always be followed by two bytes of zero padding when it
 appears in a common network layer datagram. Note that the socket
 numbers included in the native form IPX address are part of the
 transport layer.

SIPP

 It may seem a little odd to describe the interaction with SIPP-16
 (version 6 of IP) which is another proposed candidate for the next
 generation of network layer protocols. However, if SIPP-16 is
 deployed, whether or not as the protocol of choice for replacement of
 IP version 4, there will then be four network protocols to
 accommodate.  It is prudent to investigate how SIPP-16 could then be
 integrated into the common addressing plan and datagram format.
 SIPP-16 defines 128 bit addresses, which are included in the NSAP
 addressing plan under the Internet AFI as AD number 0.1. It is not
 clear at this time what administration will hold the authority for
 the SIPP-16 numbering plan. This produces a 20 byte NSAPA, with the
 system ID field positioned exactly as expected by (e.g.) IS-IS.

McGovern & Ullmann [Page 12] RFC 1707 CATNIP October 1994

    +----------+----------+---------------+---------------------+
    |  length  |   AFI    |  IDI ...      | DSP ...             |
    +----------+----------+---------------+---------------------+
    |    19    |   192    |  AD (0.1)     |   SIPP-16 address   |
    +----------+----------+---------------+---------------------+
 The SIPP-16 addressing method (the definition of the 128 bits) will
 not be described here.
 The SIPP proposal also includes an encapsulated-tunnel proposal
 called IPAE, to address some of the issues that are designed into
 CATNIP.  The CATNIP direct translation does not use the SIPP-IPAE
 packet formats. IPAE also specifies a "mapping table" for prefixes.
 This table is kept up-to-date by periodic FTP transfers from a
 "central site." The CATNIP definitions leave the problem of prefix
 selection when converting into SIPP firmly within the scope of the
 SIPP-IPAE proposal, and possible methods are not described here.
 In translating from SIPP (IPv6) to CATNIP (IPv7), the only unusual
 aspect is that SIPP defines some things that are normally considered
 options to be "payloads" overloaded onto the transport protocol
 numbering space.  Fortunately, the only one that need be considered
 is fragmentation; a fragmented SIPP datagram may need to be
 reassembled prior to conversion.  Other "payloads" such as routing
 are ignored (translated verbatim) and will normally simply fail to
 achieve the desired effect.
 Translation to SIPP is simple, except for the difficult problem of
 inventing the "prefix" if an implementation wants to support
 translating Internet AD 0.0 numbers into the SIPP addressing domain.

Internet DNS

 CATNIP addresses are represented in the DNS with the NSAP RR. The
 data in the resource record is the NSAP, including the zero selector
 at the end. The zone file syntax for the data is a string of
 hexadecimal digits, with a period "." inserted between any two octets
 where desired for readability. For example:
 The inverse (PTR) zone is .NSAP.INT, with the CATNIP address
 (reversed).  That is, like .IN-ADDR.ARPA, but with .NSAP.INT instead.
 The nibbles are represented as hexadecimal digits.
 This respects the difference in actual authority: the IANA is the
 authority for the entire space rooted in .IN-ADDR.ARPA. in the
 version 4 Internet, while in the new Internet it holds the authority
 only for 0.C.NSAP.INT. (Following the example of 192 as the AFI
 value.) The domain 0.0.0.0.0.C.NSAP.INT is to be delegated by IANA to

McGovern & Ullmann [Page 13] RFC 1707 CATNIP October 1994

 the InterNIC. (Understanding that in present practice the InterNIC is
 the operator of the authoritative root.)

Security Considerations

 The CATNIP design permits the direct use of the present proposals for
 network layer security being developed in the IPSEC WG of the IETF.
 There are a number of detailed requirements; the most relevant being
 that network layer datagram translation must not affect (cannot
 affect) the transport layers, since the TPDU is mostly inaccessible
 to the router. For example, the translation into IPX will only work
 if the port numbers are shadowed into the plaintext security header.

References

 [Chapin93]      Chapin, L., and D. Piscitello, "Open Systems
                 Networking", Addison-Wesley, Reading, Massachusetts,
                 1993.
 [Perlman92]     Perlman, R., "Interconnections: Bridges and Routers"
                 Addison-Wesley, Reading, Massachusetts, 1992.
 [RFC791]        Postel, J., Editor, "Internet Protocol - DARPA
                 Internet Program Protocol Specification", STD 5, RFC
                 791 USC/Information Sciences Institute,  September
                 1981.
 [RFC792]        Postel, J., Editor, "Internet Control Message
                 Protocol - DARPA Internet Program Protocol
                 Specification", STD 5, RFC 792, USC/Information
                 Sciences Institute, September 1981.
 [RFC793]        Postel, J., Editor, "Transmission Control Protocol -
                 DARPA Internet Program Protocol Specification,
                 STD 7, RFC 793, USC/Information Sciences Institute,
                 September, 1981.
 [RFC801]        Postel, J., "NCP/TCP Transition Plan", RFC 801,
                 USC/Information Sciences Institute, November, 1981.
 [RFC1191]       Mogul, J., and S. Deering, "Path MTU Discovery",
                 RFC 1191, DECWRL, Stanford University, November,
                 1990.
 [RFC1234]       Provan, D., "Tunneling IPX Traffic Through IP
                 Networks", RFC 1234, Novell, Inc., June 1991.

McGovern & Ullmann [Page 14] RFC 1707 CATNIP October 1994

 [RFC1247]       Moy, J., "OSPF Version 2", RFC 1247, Proteon, Inc.,
                 July 1991.
 [RFC1287]       Clark, D., Chapin, L., Cerf, V., Braden, R., and
                 R. Hobby, "Towards the Future Internet Architecture",
                 RFC 1287, MIT, BBN, CNRI, ISI, UCDavis, December,
                 1991.
 [RFC1335]       Wang, Z., and J. Crowcroft, "A Two-Tier Address
                 Structure for the Internet: A Solution to the
                 Problem of Address Space Exhaustion", RFC 1335,
                 University College London, May 1992.
 [RFC1338]       Fuller, V., Li, T., Yu, J., and K. Varadhan,
                 "Supernetting: an Address Assignment and Aggregation
                 Strategy", RFC 1338, BAARNet, cicso, Merit, OARnet,
                 June 1992.
 [RFC1347]       Callon, R., "TCP and UDP with Bigger Addresses
                 (TUBA), A Simple Proposal for Internet Addressing
                 and Routing", RFC 1347, DEC, June 1992.
 [RFC1466]       Gerich, E., "Guidelines for Management of IP Address
                 Space", RFC 1466, Merit, May 1993.
 [RFC1475]       Ullmann, R., "TP/IX: The Next Internet", RFC 1475,
                 Process Software Corporation, June 1993.
 [RFC1476]       Ullmann, R., "RAP: Internet Route Access Protocol",
                 RFC 1476, Process Software Corporation, June 1993.
 [RFC1561]       Piscitello, D., "Use of ISO CLNP in TUBA
                 Environments", RFC 1561, Core Competence, December
                 1993.

McGovern & Ullmann [Page 15] RFC 1707 CATNIP October 1994

Authors' Addresses

 Michael McGovern
 Sunspot Graphics
 EMail: scrivner@world.std.com
 Robert Ullmann
 Lotus Development Corporation
 1 Rogers Street
 Cambridge, MA 02142
 Phone: +1 617 693 1315
 EMail: rullmann@crd.lotus.com

McGovern & Ullmann [Page 16]

/data/webs/external/dokuwiki/data/pages/rfc/rfc1707.txt · Last modified: 1994/10/28 20:41 by 127.0.0.1

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