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Packet Loss on Cisco7200 ATM subinterface


I sure hope that I could find someone to help me with the problem described below

We have a problem of packet loss on cisco 7200 Router ATM subinterface.

the case is as following.

We are a Data Carrier with an ATM core wide area Network. with Lucent CBX-500 as our Core ATM switches. and Lucent Stinger as our Access Nodes.

a customer of ours that requires a little over 32 Mbps bandwidth has a cisco 7200 router with an ATM interface connected to the OC-3 port of one of the Lucent stingers in our network.

to provide him with the required bandwidth we created point-to-point subinterfaces on our Juniper Edge Routing Switch ERX-700 ATM interface that is connected somewhere else in the network to a Lucent CBX-500 ATM core switch.

PVC's were created through the network between subinterfaces on our ERX-700 ATM port and the customers Cisco-7200 ATM port.

The problem that faces us is that upon routing traffic over one sub-interface, we suffer from 1-2 % packet loss in point to point pings of this sub-interface. while we have 0% packet loss on the other sub-inteface that has no traffic routed on it. Take in consideration that both subinterfaces are on the same physical interface from Cisco side and also the subinterfaces are on the same physical port from ERX side. also the 2 PVC's have the same exact path over the network.

also note that this happens while customer is no where near utlizing 100% of his traffic and whie there is no congestion at any point of the path of the customer

I am attaching configuration and stats related on both ERX-700 and Cisco-7200 as reference, I just removed info that would compromise customer privacy and I am willing to cooperate regarding any data required.

Your help would be extremely generous since we have been working on this case for quite some time now.

Thank you in advance

Hall of Fame Super Gold

Re: Packet Loss on Cisco7200 ATM subinterface

Hi, to begin with, your customer has npe-200, that is 10 years old product and may not keep up with E3 rates. The there are some input errors, probably circuit is not 100% clean.

Then pings to router are not conclusive, when dealing with small packet losses like 1% or son, is better to ping to ping to end-to-end. Finally IOS would benefit of upgrade to latest 12.3.

However if you want to be on the safe side, have customer upgrade to npe-400 or better.