Measuring transmission time
I'm looking for a way to know the time required by a wireless
interface to push out a certain number of packets (with a certain
size, at a certain rate, on a certain channel (hence interference)).
What I've been doing so far, is setting a fake arp table entry and use
ICMP (ping) to get this time ... BUT... what is exactly ICMP
Another point is that I would like to cut off the retransmission
mechanism AND timeout.. but I can't act directly at the MAC layer, so
I thought to send broadcast packets... which points out the second
What can I use in place of ICMP (as I need broadcast)?... I was
thinking to develop a simple UDP socket application, but I don't
really know how to measure the timings (what to probe for..)... I've
seen a previous post where people were trying to use queue_xmit or
something like that, and get direct access to the outgoing interface..
assuming that transmission would start right away, there would still
be a queue in the middle... hence I
Is there any fast solution aside using tcpdump ?
Re: Measuring transmission time
InuY4sha <firstname.lastname@example.org> wrote:[color=blue]
>I'm looking for a way to know the time required by a wireless
>interface to push out a certain number of packets (with a certain
>size, at a certain rate, on a certain channel (hence interference)).[/color]
Are you hoping to compute the elapsed time after the transfer happens, or
are you hoping to get a number you can use to predict future transfers?
I suspect you're after prediction, but I'm not convinced that is reliably
computable from user mode. Further, because wireless is so wildly
variable, as soon as you got a number, it wouldn't be applicable any more.
Tim Roberts, [email]email@example.com[/email]
Providenza & Boekelheide, Inc.