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North American Network Operators Group Date Prev | Date Next | Date Index | Thread Index | Author Index | Historical Re: CAR
Hi Christopher, If CAR is applied to the routers closest to upstream provider, the traffics can still consume the link to the provider. Plus the rate limit ACL will be huge. If we can apply CAR to the router at the upstream provider, the problem is solved. But of course we do not have access to the upstream equipments. Anyone has comments about the TCP window theory? Suan "Ken" Yeo Network Engineer Aurum Technology [email protected] ----- Original Message ----- From: "Christopher L. Morrow" <[email protected]> To: "Ken Yeo" <[email protected]> Cc: <[email protected]> Sent: Thursday, April 18, 2002 11:40 AM Subject: Re: CAR > > > On Thu, 18 Apr 2002, Ken Yeo wrote: > > > > > Hi Nanog, > > > > Scenario: > > > > Transits -----(router A)Backbone(router B)----- Customers > > > > We applied Cisco CAR at the edge routers (B) in the Backbone to rate limit > > inbound and outbound traffics to/from Customers. If transmission rate is > > higher than the rate limit threshold, IP packets are being dropped by router > > B. How do we prevent the excess IP packets to consume the transit links and > > the Backbone? Here is my understanding: > > You can't unless you CAR on all ingress interfaces on your network toward > the customers... so: > > Ingress-Provider->RTA->RTBB->RTB->Customers > > You need to CAR on all 'Ingress-Provider' links, this is a very sticky > problem (obviously) > > > > > -For TCP traffics (HTTP, FTP), TCP senders will stop sending packets when > > the TCP windows threshold is reached. > > -For UDP based audio/video trafffics, if the applications use RTSP and > > H.323, RTCP/H.245 will signal the sender to slowdown the transmission if the > > receiver lost packets. > > > > Did I miss anything? How about UDP traffics that are not using RTSP/H.323? > > > > Thanks. > > > > Suan "Ken" Yeo > > Network Engineer > > Aurum Technology > > [email protected] > >
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