FYI- For those that don't appreciate the consequences of using unproven technology. The good news on Mae-East is packet loss is down to 15% from 40%? :-( Congratulations to Sprint for picking a technology that is known to work for the Sprint NAP. FDDI works. We'll see how the others NAPs do, though I'm not encouraged by test results so far. Curtis BTW - this is Mae-East (the MFS bridged ethernet), not Mae-East+ (the bridged FDDI). ------- Forwarded Message Received: from interlock.ans.net by wawa.ans.net (AIX 3.2/UCB 5.64/4.03) id AA16341; Wed, 19 Oct 1994 06:07:44 GMT Received: from rodan.UU.NET by interlock.ans.net with SMTP id AA17574 (InterLock SMTP Gateway 1.1 for <incoming-mae-east@ans.net>); Wed, 19 Oct 1994 02:11:13 -0400 Received: from relay2.UU.NET by rodan.UU.NET with SMTP id QQxmge25650; Wed, 19 Oct 1994 02:07:15 -0400 Received: from tiny.sprintlink.net by relay2.UU.NET with SMTP id QQxmge23808; Wed, 19 Oct 1994 02:07:13 -0400 Received: from localhost.sprintlink.net (localhost.sprintlink.net [127.0.0.1]) by tiny.sprintlink.net (8.6.9/8.6.9) with SMTP id CAA16850 for <mae-east@uunet.uu.net>; Wed, 19 Oct 1994 02:07:07 -0400 Message-Id: <199410190607.CAA16850@tiny.sprintlink.net> X-Authentication-Warning: tiny.sprintlink.net: Host localhost.sprintlink.net didn't use HELO protocol From: Sean Doran <smd@sprint.net> Reply-To: smd@sprint.net To: mae-east@uunet.uu.net Subject: Moderately urgent: getting rid of annoying packet losses Date: Wed, 19 Oct 1994 02:07:06 -0400 Sender: smd@tiny.sprintlink.net The Magnum boxes are *very* unhappy with inter-packet gaps of less than about 23 microseconds, and drop back-to-back packets like superheated rocks. We have a kludge which will help until the MFS hardware gets fixed. Those of you running one Cisco with EIP 10-0 microcode or better should set the transmitter-delay of your MAE-EAST interface to 96 (0x60). This will dramatically reduce the packet loss across MAE-EAST. IMPORTANT: Those of you who have more than one box on your ethernet drop to MFS will need to a/ acquire EIP 171-1 from Cisco and load it in then b/ set the transmitter-delay of each of your MAE-EAST interfaces to 0x360 (864). The new microcode has apparently been well tested, and is doing the right thing for icm-dc-1.icp.net and sl-dc-6.sprintlink.net (drops to most of you have fallen from 40% to much less than 15%). It works by assigning new meanings to the upper 8 bits of the transmitter- delay value; this particular setting will delay the transfer of the packet to the datalink controller when there is traffic on the wire, then require an additional quiet time of 30usec, after which there will be the standard 9.6 usec IEEE 802.3 delay. (The original intent apparently was to avoid drops when bursting ethernet traffic encounters collisions by backing off on handing the packet to the datalink layer; the application here is not quite exactly what was intended, but definitely helps us). Each of your routers attached to MAE-EAST must run the new EIP 171-6 microcode and have the 0x360 transmitter-delay setting. Thanks to Robert M. Broberg of Cisco for the code. Those of you without Ciscos will have to come up with a similar hack somehow. Sean. P.S.: We are *very* keen on PSI, NETCOM, and MCI to implement the change, especially PSI. We aren't having problems with anyone else we exchange traffic with at MAE-EAST (other than Dante AS1133, but that's not a Cisco) but everyone would probably benefit from the upgrade anyway. Try pinging each of your peers in 192.41.177 a hundred or so times. - - -- Sean Doran <smd@sprint.net> SprintLink/ICM engineering +1 703 904 2089 ------- End of Forwarded Message