RFC 3539 (rfc3539) - Page 2 of 41

Authentication, Authorization and Accounting (AAA) Transport Profile

RFC 3539                 AAA Transport Profile                 June 2003


   3.  AAA Transport Profile. . . . . . . . . . . . . . . . . . . . . 12
       3.1.  Transport Mappings . . . . . . . . . . . . . . . . . . . 12
       3.2.  Use of Nagle Algorithm . . . . . . . . . . . . . . . . . 12
       3.3.  Multiple Connections . . . . . . . . . . . . . . . . . . 13
       3.4.  Application Layer Watchdog . . . . . . . . . . . . . . . 13
       3.5.  Duplicate Detection. . . . . . . . . . . . . . . . . . . 19
       3.6.  Invalidation of Transport Parameter Estimates. . . . . . 20
       3.7.  Inability to use Fast Re-Transmit. . . . . . . . . . . . 21
       3.8.  Head of Line Blocking. . . . . . . . . . . . . . . . . . 22
       3.9.  Congestion Avoidance . . . . . . . . . . . . . . . . . . 23
       3.10. Premature Failover . . . . . . . . . . . . . . . . . . . 24
   4.  Security Considerations. . . . . . . . . . . . . . . . . . . . 24
   5.  IANA Considerations. . . . . . . . . . . . . . . . . . . . . . 25
   6.  References . . . . . . . . . . . . . . . . . . . . . . . . . . 25
       6.1.  Normative References . . . . . . . . . . . . . . . . . . 25
       6.2.  Informative References . . . . . . . . . . . . . . . . . 26
   Appendix A - Detailed Watchdog Algorithm Description . . . . . . . 28
   Appendix B - AAA Agents. . . . . . . . . . . . . . . . . . . . . . 33
       B.1.  Relays and Proxies . . . . . . . . . . . . . . . . . . . 33
       B.2.  Re-directs . . . . . . . . . . . . . . . . . . . . . . . 35
       B.3.  Store and Forward Proxies. . . . . . . . . . . . . . . . 36
       B.4.  Transport Layer Proxies. . . . . . . . . . . . . . . . . 38
   Intellectual Property Statement. . . . . . . . . . . . . . . . . . 39
   Acknowledgments. . . . . . . . . . . . . . . . . . . . . . . . . . 39
   Author Addresses . . . . . . . . . . . . . . . . . . . . . . . . . 40
   Full Copyright Statement . . . . . . . . . . . . . . . . . . . . . 41

1.  Introduction

   This document discusses transport issues that arise within protocols
   for Authentication, Authorization and Accounting (AAA).  It also
   provides recommendations on the use of transport by AAA protocols.
   This includes usage of standards-track RFCs as well as experimental
   proposals.

1.1.  Requirements Language

   In this document, the key words "MAY", "MUST, "MUST NOT", "optional",
   "recommended", "SHOULD", and "SHOULD NOT", are to be interpreted as
   described in [RFC 2119].

1.2.  Terminology

   Accounting
             The act of collecting information on resource usage for the
             purpose of trend analysis, auditing, billing, or cost
             allocation.




Aboba & Wood                Standards Track