| 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 |
I have three DC900MX's in three different locations wich are connect through
SMF like in attached drawing.
The customer is complaining about "transitions, beaconings and claims".
My first reaction on this was: OK this is normal because the ring is not
closed. But the customer's point is: yes maybe, but in this case the ring
should behave like when a cable failure occurs and should wrap primary and
secondary ring together.
I'm not sure about this. Can somebody confirm this to me.
The customer thinks more to have a problem with the fibre-connections or
with the sensitivity of the receivers we use in the SMF-PMD. The fibre
is supplied by the local PPT and they garantees an attenuation of no more than
21dB for the connection. I relation of this I would like to what the output
power and the sensitivity is of the SMF-PMD's.
Or does anybody has some general remarks.
Rgds.....Peter
1 2 3
+----------+ +----------+ +----------+
| | | | | |
+B A+====+B A+====+B A|
| DC900MX | | DC900MX | | DC900MX |
| M | | M | | M |
+----+-----+ +----+-----+ +----+-----+
| | |
| | |
| | |
+----+-----+ +----+-----+ +----+-----+
| S | | B | | B |
| | | | | |
| CISCo4000| | CISCO AGS| | CISCO AGS|
+----------+ +----------+ +----------+
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 1483.1 | 56821::STEFANI | Have the # for the Mars Observer? | Tue Oct 25 1994 09:34 | 10 | |
>>closed. But the customer's point is: yes maybe, but in this case the ring
>>should behave like when a cable failure occurs and should wrap primary and
>>secondary ring together.
>>I'm not sure about this. Can somebody confirm this to me.
I agree with the customer. Once the ring wraps you should not see
constant state transitions, beacons, and claims. Looks like something
else is going on.
/l
| |||||
| 1483.2 | BIS5::RUTTENS | Tue Oct 25 1994 11:48 | 8 | ||
I forgot to mention a maybe inportant fact.
When one of the routers is switched off, the hole ring seems to RESET
and breaking down all connections.
This process takes 3/4 minutes before the network is back on line.
Rgds....P.
| |||||
| 1483.3 | y | 56821::B_CRONIN | Wed Oct 26 1994 19:41 | 22 | |
My suspicion is that there is a trace being launched by the cisco
boxes. Here are a few things to look for:
1) The ring is unusable for about 12 seconds, then the DEC products
drop off line, self test, comeback, and it starts all over again.
2) A network monitor in the ring will show the address of the beaconing
station - if you have a tekelec, DTI, or W&G monitor, set it up to
find beacons, and see who is beaconing. That will tell you where the
break is. The beacons will be there for > 10 seconds if things are
working as they should.
3) Look for the TRACE message (Master Line State) being sent from the
beaconer.
This is difficult to diagnose, so pay close attention to the lights and
the monitors.
Send me mail if you need more help on this
| |||||
| 1483.4 | Who tested the fiber? | 40222::PETTENGILL | mulp | Sat Oct 29 1994 00:18 | 2 |
Are they saying that 21db or less _is_ the number, or that they will make the number be no more than 21db if necessary. | |||||