Question

Short radio link with a data source attached with a needed throughput of 1280 Kbps over IPv6 with a UDP Stop-and-wait protocol, no other clients or noticeable noise sources in the area. How on earth can I calculate what the best packet size is to minimise overhead?

UPDATE

I thought it would be an idea to show my working so far:
IPv6 has a 40 byte header, so including ACK responses, that’s 80 bytes overhead per packet.
To meet the throughput requirement, 1280 K/p packets need to be sent a second, where p is the packet payload size.

So by my reckoning that means that the total overhead is (1280 K/p)*(80), and throwing that into Wolfram gives a function with no minima, so no ‘optimal’ value.

I did a lot more math trying to shoehorn bit error rate calculations into there but came up against the same thing; if there’s no minima, how do I choose the optimal value?

Answer 1

Your best bet is to use a simulation framework for networks. This is a hard problem, and doesn’t have an easy answer.

NS2 or SimPy can help you devise a discrete event simulation to find optimal conditions, if you know your model in terms of packet loss.