bandwidth

Hi,

I am thinking of desgning my first network program that would calculate bandwidth usage for hosts. Basically i think i should do this:

Code:

monitor incommig and outgoing packets.
see where does the packet point to (ie: mydomain1.com or mydomain2.com).
store the packet size.
sum up the size of the packets to calculate total bandwidth used during that session and log it.

Since I have never worked with networking, I have no idea what headers or functions i would use. Guide me to the right direction please (even if it is google)

thanks.

If you have never worked with networking, then you have a long ways to go before you do something like monitoring all packets. Doing this from scratch without using a third party library is beyond even a lot of advanced programmers.

Start with something simple like a chat application, or a file transfer program. Then you can work your way up to something like an irc or ftp client.

i was going to use third parties libararies. But i do not know which headers and functions would be required to accomplish this program.
(and i think it would be easier to monitor bandwidth than making live chat or ftp)

and i think it would be easier to monitor bandwidth than making live chat or ftp

I'm sorry, but you're wrong. Writing a chat client requires just the basic knowledge of network programming. Packet monitoring requires a lot more.

Anyways, the best third party library for packet capture is libpcap. It's not that hard to use, you can start monitoring packets with just a few functions calls. Parsing packet data requires knowledge of how IP packets are composed. The two main packets you will be looking at are TCP and UDP.

bithub is totally correct here, chat clients are miles easier than creating a packet monitor. With a chat client you need only look at the data and check for errors, while with packet monitoring you need to know much more about the packet and how everything works. definately check out libpcap, I know I tried it once without libpcap and it was confusing and I finally dropped the project. I am no expert for sure, but trying to learn things is always a good thing. Just don't make things too hard on yourself or more than likely you will give up before you ever learn.