RFC 1638 (rfc1638) - Page 2 of 28
PPP Bridging Control Protocol (BCP)
Alternative Format: Original Text Document
RFC 1638 PPP Bridging June 1994 4.1.4 Separation of Spanning Tree Domains ............. 11 4.2 Bridged LAN Traffic ............................. 12 4.3 Spanning Tree Bridge PDU ........................ 16 5. BCP Configuration Options ............................. 17 5.1 Bridge-Identification ........................... 17 5.2 Line-Identification ............................. 19 5.3 MAC-Support ..................................... 20 5.4 Tinygram-Compression ............................ 21 5.5 LAN-Identification .............................. 22 5.6 MAC-Address ..................................... 23 5.7 Spanning-Tree-Protocol .......................... 24 APPENDICES ................................................ 26 A. Tinygram-Compression Pseudo-Code ................... 26 SECURITY CONSIDERATIONS ................................... 27 REFERENCES ................................................ 27 ACKNOWLEDGEMENTS ............................................. 28 CHAIR'S ADDRESS .............................................. 28 AUTHOR'S ADDRESS ............................................. 28 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 [3]. Although IEEE committee 802.1G is addressing remote bridging [2], neither standard directly defines the mechanisms for implementing remote bridging. Technically, that would be beyond the IEEE 802 committee's charter. However, both 802.1D and 802.1G allow for it. The implementor may model the line either as a component within a single MAC Relay Entity, or as the LAN media between two remote bridges. Baker & Bowen
