Hi Joseph thanks for you prompt reply.

Do you know if there is some document that can explain how to calculate an estimation time.

Supposing that I have 100Mb/s interface and 23000 total packets per seconds (in and out) and each packet have a size of 274 byte (2192 bit) what can be the delay.

Thanks

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You would need to also know your arrival distribution.

But assuming a more or less random arrival rate, and (from your bandwidth consumption numbers) about 50%, I recall (assuming we can use a M/M/1 model) you would average less than 2 (or 1?) packet in the queue.  Assuming 1 packet packet in queue, 2K bits / 100 Mbps, average queuing delay of 2 ms.  (NB: there are some [free] queuing calculators that can be, but couldn't find a good one just now.)

I joseph

I found the following formula:

1/(μ-λ)

where μ is the service rate (e.g., the number of packets per second the interface can sustain) and λ is the arrival rate (the average rate at which packets are arriving to be serviced).

The service rate μ = T/P (where T = the transmission rate of the facility and P = the average packet size).

Suppose to have 100Mbit/s connection (100.000.000 bit/s). From the captured traffic I will take the maximum packet size which is 274 bytes (2192 bit). So the service rate for a 100Mbit/s interface receiving those packets size is:

μ = 100.000.000/2192 = 45620,4 packets/sec

Right?

Considering that from the captured traffic the arrival rate on the interface is 23000 total packets/sec (in average) the delay in the interface directly connected to the server will be:

1/(45620-23000) = 0,000042 sec = 0,042 ms

I think I miss something or the formula is not correct.

What do you think

Thanks

Andrea