Data Link Switching: Switch-to-Switch Protocol AIW DLSw RIG: DLSw Closed Pages, DLSw Standard Version 1
RFC 1795

Document Type RFC - Informational (April 1995; No errata)
Obsoletes RFC 1434
Last updated 2013-03-02
Stream Legacy
Formats plain text html pdf htmlized bibtex
Stream Legacy state (None)
Consensus Boilerplate Unknown
RFC Editor Note (None)
IESG IESG state RFC 1795 (Informational)
Telechat date
Responsible AD (None)
Send notices to (None)
Network Working Group                                    L. Wells, Chair
Request for Comments: 1795             Internetwork Technology Institute
Obsoletes: 1434                                        A. Bartky, Editor
Category: Informational                              Sync Research, Inc.
                                                              April 1995

             Data Link Switching: Switch-to-Switch Protocol
       AIW DLSw RIG: DLSw Closed Pages, DLSw Standard Version 1.0

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.


   This RFC describes use of Data Link Switching over TCP/IP. The RFC is
   being distributed to members of the Internet community in order to
   solicit their reactions to the proposals contained in it.  While the
   issues discussed may not be directly relevant to the research
   problems of the Internet, they may be interesting to a number of
   researchers and Implementers.

   This RFC was created as a joint effort of the Advanced Peer-to-Peer
   Networking (APPN) Implementers Workshop (AIW) Data Link Switching
   (DLSw) Related Interest Group (RIG).  The APPN Implementers Workshop
   is a group sponsored by IBM and consists of representatives of member
   companies implementing current and future IBM Networking
   interoperable products. The DLSw Related Interest Group was formed in
   this forum in order to produce a single version of the Switch to
   Switch Protocol (SSP) which could be implemented by all vendors,
   which would fix documentation problems with the existing RFC 1434,
   and which would enhance and evolve the protocol to add new functions
   and features.

   This document is based on RFC 1434.  This document contains
   significant changes to RFC 1434 and therefore obsoletes that

   Any questions or comments relative to the contents of this RFC should
   be sent to the following Internet address:

   NOTE 1: This is a widely subscribed mailing list and messages sent to
   this address will be sent to all members of the DLSw mailing list.
   For specific questions relating to subscribing to the AIW and any of

Wells & Bartky                                                  [Page 1]
RFC 1795                  Data Link Switching                 April 1995

   it's working groups send email to:

   Information regarding all of the AIW working groups and the work they
   are producing can be obtained by copying, via anonymous ftp, the file
   aiwinfo.psbin or aiwinfo.txt from the Internet host, located in directory aiw.

   NOTE 2:  These mailing lists and addresses are subject to change.

1.  Introduction

   Data Link Switching (DLSw) is a forwarding mechanism for the IBM SNA
   (Systems Network Architecture) and IBM NetBIOS (Network Basic Input
   Output Services) protocols.  This memo documents the Switch-to-Switch
   Protocol (SSP) that is used between Data Link Switches.  This
   protocol does not provide full routing, but instead provides
   switching at the SNA Data Link layer (i.e., layer 2 in the SNA
   architecture) and encapsulation in TCP/IP for transport over the
   Internet.  This RFC documents the frame formats and protocols for
   multiplexing data between Data Link Switches. The initial
   implementation of SSP uses TCP as the reliable transport between Data
   Link Switches.  However, other transport connections such as OSI TP4
   could be used in the future.

   A Data Link Switch (abbreviated also as DLSw in this document) can
   support  SNA (Physical Unit (PU) 2, PU 2.1 and PU 4) systems and
   optionally NetBIOS systems attached to IEEE 802.2 compliant Local
   Area Networks, as well as SNA (PU 2 (primary or secondary) and PU2.1)
   systems attached to IBM Synchronous Data Link Control (SDLC) links.
   For the latter case, the SDLC attached systems are provided with a
   LAN appearance within the Data Link Switch (each SDLC PU is presented
   to the SSP protocol as a unique MAC/SAP address pair).  For the
   Token-Ring LAN attached systems, the Data Link Switch appears as a
   source-routing bridge.  Token-Ring Remote systems that are accessed
   through the Data Link Switch appear as systems attached to an
   adjacent ring.  This ring is a virtual ring that is manifested within
   each Data Link Switch.

1.1  Backwards Compatibility with RFC 1434

   This document defines significant changes to RFC 1434 and does not
   state details on how to interoperate with RFC 1434 or "enhanced"
   implementations (e.g., those that added enter and exit busy flow
   control).  It is up to the implementer to refer to RFC 1434 and/or
   any other vendor's documentation in order to interoperate with a
   given vendor's implementation, if interoperability with pre-AIW DLSw
   RIG standards is desired.
Show full document text