| 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 |
Hi,
Customer's questions after analyzing ring with Chamelan 100:
Every DEFCN V3.1 sends SMT, NIF Announcement Frames with DA=SA.
Refering to SMT 6.2 SMT/NIF/Announcement Frames should be sent to
DA=Broadcast, why this difference ? (Same with V3.2.0 FT)
Those frames should be sent every:
T_Notify = 30 seconds (default)
T_Notify_Min = 2 seconds T_Notify_Max = 30 seconds
It looks like T_Notify on DEFCN V3.1 is 10 seconds, why ?
(Same with V3.2.0 FT)
If those frames are sent for Duplicate Address Test check,
what happens if because of a physical error, bits A or C are set to 1 ?
=======================================================================
Now about DEFCN OBM Menu setting TVX
------------------------------------
TVX> Valid Transmission Time: 2.62144 ms under V3.1
TVX> Valid Transmission Time: 3.19488 ms under V3.2.0 FT
What is Digital's recommended value ?
-------------------------------------------------------------------
DECconcentrator 500 Local Management
Set Menu
1. IP Address
2. Gateway Address
3. Requested TRT
4. LEM Threshold
5. TVX >
6. Update Switch Off
7. Ring Purger Enable False
8. Password
9. Defaults and Reset
0. Restricted Token Timeout
e. Exit
Please enter a value from 3.4 to 5.2224
^^^^^^^^^^^^^
-----------------------------------------------------------------------
but you can still set it to 2.5 ms.
-----------------------------------------------------------------------
DECconcentrator 500 Local Management
Show Line Characteristics
Link Address: 08-00-2B-34-A1-5B
Port No.: 1
Datalink Version: 1.0.0
Datalink Type: FDDI Ring
Station ID: 00-00-08-00-2B-34-A1-5B
Station Type: Dual Attachment Concentrator
Management Sets Allowed Switch: Enabled
Maximum TRT: 173.015040 ms
Requested TRT: 10.997760 ms
Valid Transmission Time: 2.498560 ms
^^^^^^^^
SMT Version ID: 1
SMT Resource Index: 11
Frame Strip Mode: SA Match
Thanks for all answers
Walter
| T.R | Title | User | Personal Name | Date | Lines |
|---|---|---|---|---|---|
| 940.1 | DEC additional "features" | QUIVER::PARISEAU | Luc Pariseau | Fri Apr 23 1993 09:58 | 32 |
This keeps coming up! We send a NIF Announcement frame to the Broadcast address with NSA (just like the SMT spec says) AND we send in addition a NIF Announcement Frame to our own address as an additional duplicate test. This is true for ALL DEC FDDI products. T_Notify is set to 10 seconds by default for all DEC products. Why? Maybe Paul can say why that number was picked. It really doesn't matter much. You have to wait at least 30+ seconds if you want to draw a ring map by just listening to NIF frames because everybody else uses 30 seconds for their default T_Notify. If A bit is set due to a physical error... We might think this is a duplicate for a while. And then, unless this keeps happening, it will go away. TVX I believe should be 2.5 msec. It used to be 3.1. If it is wrong I don't believe that's a big deal. The 'recommended' value is whatever the value we ship with (that's MY recommendation... I don't see any reason why a customer would want to change TVX or T-Req...your basic customer that is). Range of values for TVX via OBM...looks like a small bug. Since 3.2 of DEFCN just shipped, this will not be fixed anytime soon. Luc | |||||
| 940.2 | KONING::KONING | Paul Koning, A-13683 | Fri Apr 23 1993 16:13 | 10 | |
The TVX range confusion is because at one time it looked like MAC-2 was going to change the range. That ended up not happening, and the "old" range was reinstated. I don't remember why T_Notify defaults to 10. There must have been some reason at one time... Was it the standard value at one point, perhaps? If 30 is the current standard default, the architecture spec should probably change accordingly. Note that it hasn't been updated to track the latest SMT. paul | |||||