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Packet drop in E1 Link

I having a basic query in troubleshooting E1 link , here im facing packet drop in the link and we are testing by providing local loop and remote loop from the CSU/DSU at local point and at  remote point . I have tried  ping test while the loop is given at local point and remote point ie i have pinged my local serial interface IP address (eg -local  & -remote ) in Remote Loop  i could see no errors and drops and also the traffic on the interface output and input is the same(eg input rate 1000bps and output rate  1000bps) .My query is that when i am pinging the local interface IP does the icmp packet  travels till the loop point  and comes to the same interface(like a boomerang) .Also is this a proper way of testing the link .Kindly provide best practices in checking the issue .

ICMP packet


R1         Local CSU/DSU             |  Remote CSU/DSU (remote loop given )

O-----------O------------------------------O |--------------------------------------O R2


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Packet drop in E1 Link

Hi Friends expecting your advise on this issue

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Packet drop in E1 Link

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Packet drop in E1 Link

1. Walk your loop tests one at a time. for example moving from right to left in the diagram.

loop up the local  csu/dsu. run a test. drop the loop.

loop up the remote end. and repeat.

Is your telco involved in this testing ?

When you say you are dropping packets, what is the evidence ?

Has this link had problems in the past ?

Community Member

Re: Packet drop in E1 Link


The link is having packet drop when i ping router A to Router B  and it also had in past which was due to Telco end issue  , my telco is involved and he did a bert test from router A to  till the remote end  (Router B )Mux and there was no error in his test so further we are checking the remote end MUx to router part  . Also my question here is, when im pinging the self ip address of the router A which is recieving a loop from Remote end CSU /DSU does my packets are going like a boomerang and coming to me because im finding input rate and outrate as the same (also explained above in the diagram ) .

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Packet drop in E1 Link


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