RFC 3518 (rfc3518) - Page 2 of 40


Point-to-Point Protocol (PPP) Bridging Control Protocol (BCP)



Alternative Format: Original Text Document



RFC 3518          PPP Bridging Control Protocol (BCP)         April 2003


       3.1  LAN Frame Checksum Preservation ..................    7
       3.2  Traffic having no LAN Frame Checksum .............    7
       3.3  Tinygram Compression .............................    8
       3.4  Virtual LANs .....................................    8
       3.5  Bridge Control Packet Indicator ..................    9
   4.  A PPP Network Control Protocol for Bridging ...........   10
       4.1   Sending Bridge Frames ...........................   11
            4.1.1  Maximum Receive Unit Considerations .......   11
            4.1.2  Loopback and Link Quality Monitoring ......   11
            4.1.3  Message Sequence ..........................   11
            4.1.4  Separation of Spanning Tree Domains .......   12
       4.2  Bridged LAN Traffic in IEEE 802 Untagged Frame ...   13
       4.3  Bridged LAN Traffic in IEEE 802 Tagged Frame .....   17
       4.4  Bridge management protocol data unit .............   21
   5.  BCP Configuration Options .............................   22
       5.1  Bridge-Identification ............................   22
       5.2  Line-Identification ..............................   24
       5.3  MAC-Support ......................................   25
       5.4  Tinygram-Compression .............................   26
       5.5  MAC-Address ......................................   27
       5.6  Spanning Tree Protocol (old formatted) ...........   28
       5.7  IEEE-802-Tagged-Frame ............................   30
       5.8  Management-Inline ................................   31
       5.9  Bridge-Control-Packet-Indicator ..................   32
   6.  Changes From RFC 2878 .................................   33
   7.  Security Considerations ...............................   33
   8.  Intellectual Property Notice ..........................   33
   9.  IANA Considerations ...................................   34
   10. Acknowledgments .......................................   34
   Appendices ................................................   35
      A.     Spanning Tree Bridge PDU (old formatted) ........   35
      B.     Tinygram-Compression Pseudo-Code ................   36
   References ............................. ..................   38
   Authors' Addresses ........................................   39
   Full Copyright Statement...................................   40

1.  Historical Perspective

   Two basic algorithms are ambient in the industry for Bridging of
   Local Area Networks.  The more common algorithm is called
   "Transparent Bridging", and has been standardized for Extended LAN
   configurations by IEEE 802.1.  The other is called "Source Route
   Bridging", and is prevalent on IEEE 802.5 Token Ring LANs.

   The IEEE has combined these two methods into a device called a Source
   Routing Transparent (SRT) bridge, which concurrently provides both
   Source Route and Transparent bridging.  Transparent and SRT bridges
   are specified in IEEE standard 802.1D-1998 [8].



Higashiyama, et al.         Standards Track