NEC's Simple Middlebox Configuration (SIMCO) Protocol Version 3.0
RFC 4540

Network Working Group                                     M. Stiemerling
Request for Comments: 4540                                    J. Quittek
Category: Experimental                                               NEC
                                                                C. Cadar
                                                                May 2006

   NEC's Simple Middlebox Configuration (SIMCO) Protocol Version 3.0

Status of This Memo

   This memo defines an Experimental Protocol for the Internet
   community.  It does not specify an Internet standard of any kind.
   Discussion and suggestions for improvement are requested.
   Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2006).

IESG Note

   The content of this RFC was at one time considered by the IETF, and
   therefore it may resemble a current IETF work in progress or a
   published IETF work.  This RFC is not a candidate for any level of
   Internet Standard.  The IETF disclaims any knowledge of the fitness
   of this RFC for any purpose and in particular notes that the decision
   to publish is not based on IETF review for such things as security,
   congestion control, or inappropriate interaction with deployed
   protocols.  The RFC Editor has chosen to publish this document at its
   discretion.  Readers of this RFC should exercise caution in
   evaluating its value for implementation and deployment.  See RFC 3932
   [RFC3932] for more information.

Abstract

   This document describes a protocol for controlling middleboxes such
   as firewalls and network address translators.  It is a fully
   compliant implementation of the Middlebox Communications (MIDCOM)
   semantics described in RFC 3989.  Compared to earlier experimental
   versions of the SIMCO protocol, this version (3.0) uses binary
   message encodings in order to reduce resource requirements.

Stiemerling, et al.           Experimental                      [Page 1]
RFC 4540            NEC's SIMCO Protocol Version 3.0            May 2006

Table of Contents

   1. Introduction ....................................................4
      1.1. Terminology ................................................4
      1.2. Binary Encodings ...........................................4
   2. Compliance with MIDCOM Protocol Semantics .......................5
   3. SIMCO Sessions ..................................................6
   4. SIMCO Message Components ........................................6
      4.1. Message Types ..............................................7
      4.2. The SIMCO Header ...........................................7
           4.2.1. Basic Message Types .................................8
           4.2.2. Message Sub-types for Requests and Positive
                  Replies .............................................8
           4.2.3. Message Sub-types for Negative Replies ..............8
           4.2.4. Message Sub-types for Notifications .................9
           4.2.5. Transaction Identifier ..............................9
      4.3. The SIMCO Payload .........................................10
           4.3.1. SIMCO Protocol Version Attribute ...................11
           4.3.2. Authentication Attributes ..........................11
           4.3.3. Middlebox Capabilities Attribute ...................12
           4.3.4. Policy Rule Identifier Attribute ...................13
           4.3.5. Group Identifier Attribute .........................13
           4.3.6. Policy Rule Lifetime Attribute .....................13
           4.3.7. Policy Rule Owner Attribute ........................14
           4.3.8. Address Tuple Attribute ............................14
           4.3.9. PRR Parameter Set Attribute ........................16
           4.3.10. PER Parameter Set Attribute .......................18
   5. SIMCO Message Formats ..........................................19
      5.1. Protocol Error Replies and Notifications ..................19
           5.1.1. BFM Notification ...................................19
           5.1.2. Protocol Error Negative Replies ....................19
      5.2. Session Control Messages ..................................20
           5.2.1. SE Request .........................................20
           5.2.2. SE Positive Reply ..................................21
           5.2.3. SA Positive Reply ..................................21
           5.2.4. SA Request .........................................21
           5.2.5. ST Request and ST Positive Reply ...................22
           5.2.6. SE Negative Replies ................................22
           5.2.7. AST Notification ...................................23
      5.3. Policy Rule Control Messages ..............................23