router throughput final definition

[luckymike33]

Hi,

I am just trying to clarify something once and for all - to put my mind at ease.

I have a scenario with a customer trying to upload data through a 400Mbps circuit, using a 4431 router. Currently this router has no performance license applied and we are seeing a throughput of 250-260 Mbps, via iperf.

The key questions is this - does the base 500Mbps 'performance' equate to 250Mbps in (Lan interface) and 250 Mbps out (Wan interface)?

If so - that would mean this router with a performance license applied (giving 1Gbps performance) would really allow a concurrent 250Mbps upload and 250Mbps download - Is that correct?

I am not slightly bothered by the marketing terminology involved in any of this, I just want to clearly understand the definition of the term 'performance', in this context.

I would really value this assistance, as I am seeing conflicting results and I need the definitive answer on this.

Best wishes

Mike

[Joseph W. Doherty · Accepted solution]

My understanding is, on an ISR 4K, the bandwidth is a software cap for the total aggregate bandwidth passing through the router. I.e. all the egress bandwidths, combined, shouldn't exceed the performance cap.

"The key questions is this - does the base 500Mbps 'performance' equate to 250Mbps in (Lan interface) and 250 Mbps out (Wan interface)?"

No, your aggregate for that is only 250 Mbps.

[luckymike33]

Hi Joseph,

thanks for this -- It has been a very useful sanity check. I need to remember only to count either ingress, or egress traffic, not both.

Very helpful.

Best wishes

Mike

[Joseph W. Doherty]

Yes all ingress or all egress not both, however, I'm unsure whether the router counts bandwidth that's discarded (especially ingress). I think what is actually counted is traffic that transits across the router's backplane.

[nasir]

In this case where user is trying to upload at 250mbps, 250m ingress, 250m egress= throughput aggregate is 250mbps.
However, in real-world scenarios there would also be traffic flowing in the other direction, not related to this particular upload. Assuming that is also 250mbps (for simplicity) then it would be egressing on the other side. So applying the same formula of throughput=sum of all egress bandwidths, your throughput aggregate would be 500Mbps.

I think....