North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical RE: Lucent GBE (4 x VC4) clues needed
> -----Original Message----- > From: [email protected] [mailto:[email protected]] On > Behalf Of Saku Ytti > Sent: Thursday, September 21, 2006 9:12 AM > To: [email protected] > Subject: Lucent GBE (4 x VC4) clues needed > > > (oops technical question in nanog, wearing my asbestos suit) > > Consider this topology > > GSR - 3750 --(GE over 4xVC4) - NSE100 - NSE100 --(GE over > 4xVC4) -- 3550 - GSR > > All other fibres are dark fibres, except marked. > > When we ping either NSE100 <-> GSR leg, when there is no > background traffic there is no packet loss. If there is even > few Mbps, lets say 10Mbps of background traffic we get 1-5% > packet loss on 1500 bytes, and bit less packet loss on small > packets. As background traffic increases packet loss quickly > increases. > > We tried to replace (GSR-3750) with 7600, but same issue persisted. > > We've measured both Lucent GBE legs with having loop in other > end and pushing tests from EXFO and Smartbits gear through > the loop, no errors can be detected in RFC tests. > > There isn't very much that can be configured in the Lucent, > and we've tried pretty much every setting. We've tried to set > autonego on and off in every gear in the path, without any > changes to observed behaviour. We've also tried to use use > 1xVC4, without any changes to the behaviour. All VC4's in > given leg are using same path. > Even though we test the packet loss pinging from router link > to router link, same packet loss is experienced for transit > traffic also. We've tried to turn PXF off in NSE100. Packets > between NSE100 <-> NSE100 over dark fibre are not lost. > > We're pretty much utterly without clues. All I can think off > is some obscure IFG issue, that is, NSE100 would have less > than perfect timing for IFG which would confuse Lucent > regarding what is part of which frame. Does stuff like this > really happen? > > NSE100 drops bad IP packets in PXF and there is only shared > counter, so I can't tell if I get CRC for IP, I just loose > the packets. But IS-IS is not handled in PXF, and I get > %CLNS-4-LSPCKSUM and %CLNS-3-BADPACKET messages over both > Lucent legs, but not between the NSE100's. > So I assume the packets are not dropped, but broken. > > > I swear next time I'll complain about some political issue, thanks, > -- > ++ytti > Silly question (considering that you stated that IS-IS is borked also, which is not handled by PXF - but did you try disabling PXF? There's a reason why Cisco discontinued every product that "features" it. It's broken.
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