Hello Alex, I'd say this sounds obvious, but may be deceptively so... If you are taking a pipe capable of 1000 mbit, and rate-limiting it to 311 mbit, the logic used may be: In the last 1000 msec have there been more than 311mbits? If yes: drop. What you want is to shape the traffic, so the rule would be: In the last 1000 msec have there been more than 311 mbits? If yes: store until the msec period is up, then transmit. If you are pushing 100 mbits over this link, it is entirely likely that there will be a few sub-second burts up to 1000 mbit, and a few sub-second drops to 0mbit. An option for you would be to just figure out what the exact rate-limiting rules are, and then shape it into those rules on your side of the link -- assuming they wont change it to a shaping rule. --Phil -----Original Message----- From: owner-nanog@merit.edu [mailto:owner-nanog@merit.edu] On Behalf Of Alex Rubenstein Sent: Monday, July 15, 2002 10:48 PM To: nanog@merit.edu Subject: fractional gigabit ethernet links? Hello, I'm trying to troubleshoot a problem with a fractional (311 mbit/second) gigabit-ethernet line provided to me by a metro access provider. Specifically, it is riding a gig-e port of a 15454. The behavior we are seeing is an occasional loss of packets, adding up to a few percent. When doing a cisco-type ping across the link, we were seeing a consistent 3 to 4 percent loss. For fun, the provider brought it up to 622 mbit/second, and loss dropped considerably, but still hangs at about 1 to 2 percent. There is no question in my mind the issue is with the line, as we've done a wide variety of tests to rule out the local equipment (MSFC2s, FYI). Any clues would be exceptional. -- Alex Rubenstein, AR97, K2AHR, alex@nac.net, latency, Al Reuben -- -- Net Access Corporation, 800-NET-ME-36, http://www.nac.net --