| 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 |
A customer here in London is doing some testing with NSC in particular the translating option for the 64/6800 series. They have come up with some interesting information: NSC are having trouble with implementing translating functionality using the AT&T chipset (can't keep the ring going for more than a couple of hours - what ever that means) so they are abandoning the AT&T Chipset (for the moment) and using the Nat Semi chipset they already use in the 6600 - this will of course mean lower throughput but will they tell? During testing they have found it possible to lock FDDI ports at will by removing the fibre slowly from its socket (reproducing increasing bit error rate?) and very variable wrap times - reported in terms of void frames as being from a few to many hundreds when they make arbitary breaks. Tony.
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 669.1 | KONING::KONING | Paul Koning, A-13683 | Fri Aug 07 1992 12:00 | 8 | |
Slowly extracting a plug to introduce bit errors is a trick Jerry Hutchison demonstrated a long time ago. That would not lock up the port in a correct implementation, though. Could you give a bit more detail about the "variable wrap time"? That sounds interesting, but I don't really understand it. paul | |||||
| 669.2 | Nat Semi Chips | VIVIAN::MILTON | Invisible person it seems! | Mon Aug 10 1992 09:24 | 12 |
Paul, I've just rechecked with them. It seems that as the AT&T Chipset ain't working for NSC, the customer is testing with the NSC 6600 - so this is with Nat Semi Chips. This is all down to slow removal of fibre - remove it fast and they get immediate wrap (1 beacon and 2 claim), remove it slowly and they get a wrap after about 8ms and 500 claims - the LEM reports exessive bit errors, the port stays locked and the ring stays wrapped even after remaking the fibre connection. They say that the only way they can find out of this is to re-boot the brouter. Tony. | |||||