mae-west congestion

Jonathan Heiliger loco at MFST.COM
Fri Mar 22 03:06:21 UTC 1996

On Thu, 21 Mar 1996, Mark Boolootian wrote:

> I'm interested in knowing what happened between March 6 and March 7 on
> the Ames FDDI ring.  That's when the utilization jumped from around 60% to
> 90%.  Also of interest is that it appears MFS stopped collecting stats
> late in the afternoon, with utilization around 60%, on the 6th, and
> didn't start collecting again until around noon on the 7th,  at which time
> utilization is running at 90%.
> Anyone know what happened?

Something along the lines that we noticed the NetEdge's were no longer
collecting proper statistics on the FDDI interfaces.  Rather than
measuring total traffic, it only measured traffic that was forwarded over
another link.  We switched the data collection around which caused the
hiccup in the graphical statistics. 

On March 20th, Lance Tatman, notified the MAE-West customers via the
mailing list, that NASA had procured funds to obtain a Gigaswitch and that
he is expecting delivery "towards the end of March." 

Once that Gigaswitch is received, we will solve two problems.  #1)
Congestion on the FDDI at Ames.  #2) Is caused by #1, in that the NetEdge
is having to "think" about discarding packets it cannot deliver onto the
existing FDDI due to congestion.  Secondly, we could *possibly* be running
into a CPU limit on the NetEdge's where it's coming closs to it's PPS
processing limit. 

#2 will be rectified by removing the NetEdge's from service, and
terminating the OC-3c on the DEC Gigaswitch itself.  However, in order for
this to happen, NASA has to turn up its Gigaswitch. ;-)

Between now and the time the Gigaswitch is turned up, several Ames
connected carriers are obtaining connections into the San Jose (MFS)
Gigaswitch.  This should provide them additional redundancy and reduce
load on their backhaul links as well as the individual "sections" of the


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