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New Member

show frame-relay map output

I am getting the following output from my show frame-relay map statement. My question is: How do I interpret the BW=16000 statement?

MDS-Lyles#sh frame-relay map

Serial0 (up): ip 172.16.254.17 dlci 100(0x64,0x1840), static,CISCO, BW = 16000, status defined, active

That does not match how the circuit is defined on the serial port ( 64k ) or the actual line speed ( 64k ). So, is it my CIR as set by the telco?

If it is, I have an issue to take up with my Telco. But, I would like to be sure first.

2 REPLIES
New Member

Re: show frame-relay map output

I would say yes this is your CIR. Are you shaping your traffic or any type of QOS or limiting?

I would accually look at you real world traffic throughput before complaining. can you peg the ckt at 64k/bps or is it throttled at 16k?

If your int stats show more that 16K then you could be getting more that you are paying for. :)

New Member

Re: show frame-relay map output

By receiving the BW=16000 in your LMI updates indicates your Telco is Using Cisco/Stratacom Wan switches for their Frame Relay network. The 16000 is reporting your CIR as set up on the Telco switch, HOWEVER the Stratacom implementation of Frame Relay uses MIR, PIR, QIR & CIR (opposed to standards CIR, Bc & Be) All Telco's oversubscibe their Frame Relay networks - the problem is by how much (common factor 500-600%)

The key figure in the Stratacom scenario is the MIR as this is the guaranteed rate of transmission through the network during times of congestion. Telco's can change the CIR to what they want but it is the MIR that is the real factor here. I would suggest try measuring your actual throughput over a period of time to see what you average out at. If not what you expect then start asking the Telco some testing quetions like what your PVC's Minimum Information Rate is (MIR is the key one as this is what the network will throttle back to) as well as the Peak Information rate which is your Burst abaility and what the cmax is set to on the switch (the amount of credits you have at PIR to burst at) if throughput seems accetable then the reported BW=16000 is probably a cosmetic issue as it doesn't make that much difference as it's the MIR that does. Also ask what the network oversubscription rate is and look for BECN/FECN's on you PVC(show frame-relay PVC) for signs of network congestion - if they increment a lot the the Telco may have a busy network and you should start looking at your SLA/SLG's. Also ensure you use traffic-shaping on your PVC Interface to match the Telco's parameters (MIR & PIR) as this will ensure the best throughput at IP level and dynamically react to the FECN/BECN's being sent back by the network.

Rgds

Eamonn

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