Why is the ARPANet in such bad shape these days?


Rob Austein (SRA@XX.LCS.MIT.EDU)
Sat, 27 Sep 1986 21:35 EDT


Bill,

No, the ARPANET problem is definitely not just at Stanford. MIT has
been moderately crippled by this for weeks now (since the start of the
fall semester, which is probably -not- a coincidence). MC and XX have
a hard time talking to each other and they are on the same IMP. The
NOC claims that this is true for pretty much the entire ARPAnet.
Apparently MILNET is somewhate better off.

The NOC is refering to this mess as a "congestion problem" at the IMP
level. The current theory the last few times I talked to the NOC was
that we have managed to reach the bandwidth limit of the existing
hardware. A somewhat scary thought. If this is in fact the case (and
there is circumstancial evidence that it is, such as the fact that the
net becomes usable again during off hours), we are in for a long
siege, since it is guarenteed to take the DCA and BBN a fair length of
time to deploy any new hardware or bring up new trunks.

Current thoughts and efforts at MIT are (1) we need more data on the
traffic going through the IMPs, and (2) we need to cut down on the
amount of traffic going through the IMPs. The two go along with each
other to some extent (preliminary results show that roughly 25% of the
traffic through the MIT gateway is to or from XX). Some interesting
ideas have come up for minimizing load due to email, if that turns out
to be a prime offender (surprisingly, the preliminary statistics don't
seem to indicate that). If there is anybody else out there doing
analysis of network traffic, please share it.

Also, if there is anybody from BBN who knows more about the problem
and is willing to share it, -please- do. It's hard to make any kind
of contingency plans in a vacuum.

--Rob



This archive was generated by hypermail 2.0b3 on Thu Mar 09 2000 - 14:36:35 GMT