| 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 |
At the recent NetU I was asking several FDDI gurus about the fragmentation for DECnet Phase IV and V (DECnet Host attached to FDDI WC). My understanding (after averaging the answers !)is, that under Ph IV and early Ph V (wave ++), there will be no fragmentation support. This means, our IP offering is superior than DECnet ! It was also mentionned, that we need a fragmentation spec from DECnet folks, that has to be implemented on the FDDI bridge ? And this spec doen't exist yet ? Is this true ? Cheers Walter.
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 208.1 | See reply in ENUF::PHASE_V | MARVIN::DAVISON | Eric Davison | Mon Feb 25 1991 03:38 | 7 |
Answered elsewhere. There is a very clear architecture that defines how to fragment OSI Routing protocol messages; see ISO 8473 (and maybe 10589). The bridge shouldn't need to do this since OSI TP can, and should, negotiate the appropriate PDU size to avoid fragmentation. Eric | |||||
| 208.2 | KONING::KONING | Lietuva laisva! | Tue Feb 26 1991 12:33 | 10 | |
Actually, the bridge needs to do it for the same reason it did with IP: the higher layers could potentially detect and allow for bridges in the connection setup phase, but that doesn't deal with topology changes in mid-connection. In Phase IV there is no fragmentation (the architecture has no provision for it); therefore with Phase IV nodes will use Ethernet sized packets. Phase V (OSI) does have fragmentation and full-sized packets will be used. paul | |||||