CIR and Access Rate

Reading up on frame relay and it talks about the above being different. I thought the cir and clock rate would be the same? Do they not determine the speed?

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DPG

The access information rate (AIR) is the actual link speed. The committed information rate (CIR) is the amount of bandwidth guaranteed on that link.

control

DPG wrote: »

The access information rate (AIR) is the actual link speed. The committed information rate (CIR) is the amount of bandwidth guaranteed on that link.

Ahhh, so the actual line could be a T1/E1 which would be the set via the clock rate, but the CIR could only be 256kpbs, depending on what's been purchased from the provider?

TurK-FX

as he mentioned, CIR is the lowest speed the customer will get. AIR might be higher then CIR if the traffic load is not heavy.

TurK-FX

control wrote: »

Ahhh, so the actual line could be a T1/E1 which would be the set via the clock rate, but the CIR could only be 256kpbs, depending on what's been purchased from the provider?

So if actual line is T1, the speed will be 1.544Mbit per second, but if traffic not heavy and there are available bandwich, you may get more than 1.544Mbit. But you will never get less than that.

lantech

T1 might be a bad example. I've never heard of a T1 going faster than 1.544Mbits. But it might happen.

At the place I used to work at most companies would contract for 20MB/S internet connections. That would be the CIR (Commited Information Rate). But the connections we gave them could actually handle 100MB/S. The customer would be guaranteed that 20MB/S rate but they could always go faster than that for a period of time as long as bandwidth of other customers allowed. Then at that point they may or may not be charged for going over the 20MB/S. If it happened to often then they would be forced to upgrade their bandwidth to a higher amount.

control

lantech wrote: »

T1 might be a bad example. I've never heard of a T1 going faster than 1.544Mbits. But it might happen.

At the place I used to work at most companies would contract for 20MB/S internet connections. That would be the CIR (Commited Information Rate). But the connections we gave them could actually handle 100MB/S. The customer would be guaranteed that 20MB/S rate but they could always go faster than that for a period of time as long as bandwidth of other customers allowed. Then at that point they may or may not be charged for going over the 20MB/S. If it happened to often then they would be forced to upgrade their bandwidth to a higher amount.

Thanks for that explanation. In this case would the access rate be 100MB/S? And the CIR 20MB/S?

TurK-FX

control wrote: »

Thanks for that explanation. In this case would the access rate be 100MB/S? And the CIR 20MB/S?

Exactly!!!