[C] Network Card MaxBandwidth

Aenema · 04-04-2007, 02:10 PM

Hi,
i'm trying to write a program that detects the speed of the network card connection of the host where it is running.
For example 10Mbps, 100Mbps or else.
Somebody can help me?

Thanks a Lot
Daniele

Mara · 04-04-2007, 04:08 PM

Do you want to measure it or read from the driver stats?

Aenema · 04-05-2007, 02:03 AM

I can measure the current traffic by reading the file /proc/net/dev.
What i want to know is the Total Bandwidth ( or also the free Bandwidth ). i haven't found it anywhere...
Thanks!

Mara · 04-05-2007, 02:39 PM

Then it's rather tricky. For Ethernet, for instance, you can read it from driver settings. But you will never reach the theoretical maximum. For wireless interfaces it's even worse. There's theory, but you (usually) have no guarantee. For wireless the only way is to measure.

Aenema · 04-05-2007, 03:28 PM

so you say that the best way to get an indication is to measure the traffic.ok!
Anyway i'm interested on the theoretical Bandwidth, i don't mind if it is not reacheable... is there any API that can help me?
you also said to give a look at the driver settings... can you give me some advice?
THANKS!

PS: What a Beatiful city Warsaw!

Mara · 04-07-2007, 02:52 PM

You should be able to get the stats using the netlink socket, while getting all possible interface info. libnl, which makes dealing with netlink easier, does not support it, however, so you would need to do that manually. If you have never tried it, it may be quite complicated, mostly because lack of full documentation so you need to browse the kernel code to see all you need.