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| 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 |
1334.0. "Dual Rail FDDI performance problem" by 31302::HERNAN (Peter Hernan Western RNC) Wed May 11 1994 18:00
Initial Configuration:
+-------+ +-------+
|VMS/AXP| |VMS/AXP| Only one of the two FDDI
| | | | controllers is on for
+\---\--+ +--/---/+ DECnet or IP
\ \ / /
\ \-------------/ /
\ / \ /
\/ \/
| FDDI |
\ /
\ /
-------------
// \\
// \\
+----//-+ +-\\----+
|DEC NIS| |DEC NIS| DECnet and IP routing,
| DAS | | DAS | LAVC bridging
+-----/-+ +-\-----+
/ \
|/ \|
/ \
| |
| +-------+ |
| |VMS/AXP| |
|-----+ +-----|
| +-------+ |
| |
| |
| +-------+ |
| |VMS/AXP| |
|-----+ +-----|
| +-------+ |
| |
| |
| +-------+ |
| |VMS/AXP| |
|-----+ +-----|
| +-------+ |
| |
Current Configuration:
+-------+ +-------+
|VMS/AXP| |VMS/AXP| Both of the two FDDI
|server | |server | controllers are on for
+-|-----\ /-----|-+ DECnet, IP and LAVC
| \____ ____/ |
|----- ___X___ -----|-
/ \/ \/ \
| FDDI | | FDDI |
\ / \ /
--||-- --||--
|| ||
+--||---+ +---||--+
|DEC NIS| |DEC NIS| DECnet and IP routing,
| DAS | | DAS | LAVC bridging
+-----/-+ +-\-----+
/ \
|/ \|
/ \
| |
| +-------+ |
| |VMS/AXP| |
|-----+ WS +-----|
| +-------+ |
| |
| |
| +-------+ |
| |VMS/AXP| |
|-----+ WS +-----|
| +-------+ |
| |
| |
| +-------+ |
| |VMS/AXP| |
|-----+ WS +-----|
| +-------+ |
| |
In the initial configuration performance was fine but the FDDI portion of
the network was not redundant. When a Sniffer is connected to the FDDI it
joins the ring quickly and is able to monitor the network at a regular
interval.
In the current configuration performance to the servers from the
workstations (WS) is very poor. When a Sniffer is connected to either of
the two FDDIs it takes a long time to join the ring (seems to hang).
Eventually it joins the FDDI ring but the monitoring interval is very
irregular.
In addition to the poor performance, if one of the FDDI controllers is
disabled for any reason performance gets really bad. Fail over to the second
controlled never seams to fully happen enough packets find their way to the
servers to keep DECnet and IP connections form dropping (about one or two
packets / second).
If one of the FDDI controllers in each system is disabled and the two
FDDI rings are connected as one (initial configuration) performance returns
to normal.
The Ethernets seam to operate just fine. The FDDI, when it can be
monitored is about 37% consumed according to the Sniffer ~95% of that is
Void frames. I suspect this is the ring purger and since there is so little
traffic on the FDDI the percent of voids to data frames is high.
This customer has two separate network configurations alike, both behave
the same.
All of the equipment is DEC, DECsystems (7000s and 3000s), DEC NIS 600,
DECconcentrator 500, DEChub 900s and most of the wire came from DEC.
The operating system on all systems is Open VMS/AXP v2, DECnet IV and V.
The plan is to upgrade all of the systems to VMS/AXP v6.1 and DECnet v5.7.
Posted in the FDDI and DECnet/OSI notes file.
By the way; if a connection is made from one of the DEC NISs to the other
Ethernet fail over of one of the FDDI controllers is rapid. It looks as
though the FDDI traffic between the two servers is routed by the DEC NIS to
the Ethernet to the other DEC NIS, routed to the other FDDI and to the
second server.
| T.R | Title | User | Personal
Name | Date | Lines |
|---|
| 1334.1 | | KONING::KONING | Paul Koning, B-16504 | Wed May 11 1994 18:05 | 7 |
| FLAME ON:
If you post in multiple places, SAY SO.
See my answer in the decnet-osi_for_VMS notesfile.
paul
|