Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.3 4.3bsd-beta 6/6/85; site ucbvax.BERKELEY.EDU Path: utzoo!decvax!ucbvax!XX.LCS.MIT.EDU!SRA From: SRA@XX.LCS.MIT.EDU (Rob Austein) Newsgroups: mod.protocols.tcp-ip Subject: Why is the ARPANet in such bad shape these days? Message-ID: Date: Sat, 27-Sep-86 21:35:00 EDT Article-I.D.: XX.SRA.12242404326.BABYL Posted: Sat Sep 27 21:35:00 1986 Date-Received: Sun, 28-Sep-86 15:59:21 EDT References: Sender: daemon@ucbvax.BERKELEY.EDU Organization: The ARPA Internet Lines: 33 Approved: tcp-ip@sri-nic.arpa 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