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Conference 7.286::fddi

Title:	FDDI - The Next Generation

Moderator:	NETCAD::STEFANI

Created:	Thu Apr 27 1989
Last Modified:	Thu Jun 05 1997
Last Successful Update:	Fri Jun 06 1997
Number of topics:	2259
Total number of notes:	8590

48.0. "DEC's FDDI - packet fragmentation/re-assembly???" by AUNTB::HYMES (Software Services) Tue Apr 03 1990 07:31

    Do/will DEC's FDDI products support packet fragmentation/reassembly?
    If a large packet comes off of a FDDI ring, and must traverse
    a standard 10 mb Ethernet to get to another FDDI ring, will the
    packet be properly disassembled and re-assembled?
    
    Are there any kind of standards defined for packet fragmentation and
    re-assembly?  (...that would enable a "third party" bridge to
    successfully re-assemble a packet fragmented by a DEC bridge?)
    
    I would appreciate any information on this subject.
    Thanks,
    Pat

T.R	Title	User	Personal Name	Date	Lines
48.1	We do it in the bridge	AKO569::JOY	Get a life!	`Tue Apr 03 1990 12:19`	9
	Our bridges will do IP packet fragmentation. It is up to the destination nodes to do the reassembly. Our bridges are based on and compatible with RFC-791, RFC-792 and RFC-1009. Any third-parties who conform to these RFCs will be compatible with our bridges. Manu Kaycee (Quiver::MKAYCEE) can provide you with more info on the fragmentation issue. Debbie
48.2	The bridge will also do Phase V	F104::HERNAN	Peter Hernan NCGD-DNC	`Thu Apr 12 1990 15:25`	15
	Phase V supports Network layer fragmentation and I understand the FDDI bridge will be capable of using this facility. Once Network Layer fragmentation takes place, at any point in the network the packets will not be reassembled until they reach the Network Layer of the destination node. The Phase IV Routing Layer does not support packet fragmentation. Therefore, when a Phase V system, on an FDDI network, is communicating with a Phase IV system on an Ethernet, the Phase V system will be limited by either the Phase IV Line or EXEC buffer size. regards
48.3		BERN01::DEY	PhV or Big wind, long talk, no rain	`Tue Apr 17 1990 14:44`	10
	Peter >> The Phase IV Routing Layer does not support packet fragmentation. Therefore, >>when a Phase V system, on an FDDI network, is communicating with a Phase IV >>system on an Ethernet, the Phase V system will be limited by either the Phase IV >>Line or EXEC buffer size. Do you mean, that in the transport negotiation between Ph V and Ph IV. the smallest buffer size is chosen ? and therefore no use of the max FDDI buffer size is made.
48.4		KONING::KONING	NI1D @FN42eq	`Wed Apr 18 1990 09:51`	3
	That's right. paul