Sniffing router traffic I have a 10 MB connection, which runs really good but sometimes it get slower then 56kb dialup connection, i had my provider call up and asked, what is wrong but they say too much traffic is being consumed in your house by devices on the chart of connected devices. So i had my password of wifi changed and just connected my laptop, and it was running really like a 10 MB connection, but again i am facing same issue. 
I want to monitor my network traffic and see what's the devices on router taking so much of my bandwidth and if possible website address too. I have a mac, i was wondering if there is any software that can really help me out?
It's hard to comment on your question as you didn't give many details.

You could connect a switch with monitor/mirror port functionality between your router and your DSL modem/network terminator (if that is two discrete devices for you). This way you could connect a computer to the switch's mirror port and "see" (snoop, trace) all traffic that goes out your router's WAN port and analyze it.