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Community Member

Frame relay speed

We have recently upgraded framerelay link speed to 2MB before it was 512KB. But we are unable get the 2MB link speed. Our service provider is claiming that the link speed is 2MB. He tested in front of us connected speed tester with modem. Our serial port is 1T. Where is the problem lying. what are the things to be checked?

thanks in advance.

VIP Purple

Re: Frame relay speed


first of all, check what bandwidth is actually assigned to your frame relay connection. You can use the command ´show frame-relay map´ to do that, check for the line ´BW=´, that tells you the bandwidth assigned. Your provider might allow you to burst up to 2MB.

You could implement Frame Relay Traffic Shaping, in order to guarantee that the 2MB are going through, the configuration would look like this:

interface Serial0

frame-relay traffic-shaping

frame-relay interface-dlci 102

class DLCI_102


map-class frame-relay DLCI_102

frame-relay cir 1984000

frame-relay bc 19840

Can you try to implement this, and check if that makes a difference ?



Community Member

Re: Frame relay speed

If your provider permits to use and has ELMI configured and you have 'frame-relay qos-autosense' configured on your serial interface you can run 'sh frame-relay qos-autosense' to get parameters which configured on providers site.

//Mikhail Galiulin

Re: Frame relay speed


What router are you using and what cable type?

Do I understand correctly that a speed tester from the SP with a modem achieved 2Mbps steady troughput?

How do you test the speed and conclude you do not get the 2 Mbps?

A portion of the router config could also help to understand what could be done and where potential problems are.


Hall of Fame Super Gold

Re: Frame relay speed

I believe that we need some clarification from the original poster about what they have got and what performance they are seeing.

If I understand the original post their interface is T1. So right off the bat they can not achieve 2Mb but only 1.5. And no one gets the full rated throughput since you must allow for overhead of packet headers, LMI packets, end to end keepalive (if it is configured), and other kinds of overhead such as routing protocol traffic. So it would be helpful to know what kind of throughput they are actually seeing.

There are various speed testing services which some people use. But my reservation about those is that you will report the speed of the slowest link between the far end of the segment and the test site, not necessarily the speed of the segment that you are interested in. I think that a better test is to put a reasonably large file on a machine at one end of the link and transfer that file to a machine at the other end of the link. Measure the time it takes to transfer the file and you have a pretty good measurement of the speed of the link.



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