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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: Problems getting Cisco router and Motorola Nextlevel system to work together
The buffers are overloading and dropping traffic. With a Cisco TAC case, the tech had me increase the buffers so much it wasn't even funny. The only problem was about and hour after we tried to tune the buffers, things got very bad and I had clear them to default to stop a very ugly bigger outage. This system does indeed involve IPTV set top boxes. I am unable to use RBE since the PVC provisioning may change on the units and the VC would not match what the dhcp lease was originally on. The way that this Motorola system implements PVCs baffles me, it does not make any sense to me. They are dynamically changing the vci assigning it out of a pool, just like DHCP does with IPs. The circuits are not SVCs and the endpoint router is seeing things change so this is not SPVCs either. I am trying to think of a way the change this to work with RBE switching, but the dynamic PVCs are throwing a monkey wrench into things. Thank for the help. -- Brian Raaen Network Engineer [email protected] On Tuesday 24 July 2007 22:58, you wrote: > > We should probably move this over to cisco-nsp. > > I'd be interested to see a 'sh buffers' because if it's > process switching that much data I bet the buffers are thrashing. > > I seem to remember working on something very similar to that > 4 or 5 years ago when a customer has brigding over a bunch of > ATM PVC's and they told me it was some type of IPTV set top box. > > We tuned the buffers really high so they didn't trim back and > it worked. > > We also do some bridging under interrupt without process > switching too last time I checked so some more data would > be helpful. > > Move it over to [email protected] and we can help > more on the Cisco side if you want. > > Rodney > > On Tue, Jul 24, 2007 at 09:25:49PM +0100, [email protected] wrote: > > > > > The router is currently configured to use IRB which is a > > > hybrid process. > > > The problems is that the IRB process is overloaded and is > > > dropping traffic faster than it can process it. > > > > Which NPE is in this router? > > > > Basically, the 7200 has underpowered CPUs and if you force it to process > > switch, then it handles a LOT LESS packets per second than you might > > think. I expect that your config is forcing process switching rather > > than fast switching. > > > > The only three solutions are > > > > A) run less traffic through the 7200 so that process switching can cope > > > > B) stop using the feature that forces process switching > > > > C) replace the 7200 with a 7300 which will probably not have CPU issues. > > However, not knowing the specifics of what IRB is doing, I would advise > > you to test a replacement platform before committing to it. > > > > Oh well, maybe 4 solutions. If you are using a weak NPE such as NPE-200 > > you may be able to get some joy by upgrading to a more powerful one. For > > instance an NPE-400 should handle roughly twice the load of an NPE-200. > > > > --Michael Dillon > >
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