| 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 |
My customer has told me that when a Cisco router on a dual-ring
FDDI goes from a wrap configuration back to normal operation
that it leaves garbage on the secondary ring.
What will our concentrators do with this errant data?
Will the ring purger clean up the secondary ring if the ring
is operating on the primary ring?
Will this errant traffic effect the operation of our FDDI
concentrator or bridges?
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 544.1 | KONING::KONING | Paul Koning, A-13683 | Tue Apr 21 1992 10:19 | 20 | |
Now you know why we invented the ring purger.
> What will our concentrators do with this errant data?
Propagate it. The concentrator has no way to tell the difference between
garbage frames and real frames.
> Will the ring purger clean up the secondary ring if the ring
> is operating on the primary ring?
No. Ring purger is a MAC function; we don't put a MAC on the secondary ring
so we don't clean it up.
> Will this errant traffic effect the operation of our FDDI
> concentrator or bridges?
No. We don't have a MAC there so we don't see it in bridges. Concentrators
don't care at all.
paul
| |||||
| 544.2 | and then the ring wraps... | BONNET::LISSDANIELS | Tue Apr 21 1992 17:26 | 6 | |
Paul,
Now please tell us what happens if the ring wraps AGAIN.
Then I assume we do clean up this garbage ... or ?
Torbjorn
| |||||
| 544.3 | KONING::KONING | Paul Koning, A-13683 | Tue Apr 21 1992 17:39 | 12 | |
Yes. Actually, if the station doing the wrap conforms to the standard, then that trash will disappear at that point. (Of course, if the stations conformed, the trash wouldn't appear in the first place!) This is done by the "Scrub" function, which is performed every time a port changes state. If the scrub is not performed properly, causing the trash of which you spoke to appear on what's now a wrapped ring, then the ring purger will get rid of it in the next token rotation. paul | |||||