You mentioned the four magic words 'traffic jam' and 'no connectivity' – this to me sounds like a central switch...
problem of some sort. There is no reason why a traffic jam between one or two machine should bring down a whole network!
There is a good possibility that either one of your switches or hubs is doing the damage, or you've got a problematic network card that's simply spitting out garbage constantly and therefore brining the network to its knees.
I'd advise you to check the lead indicators on your equipment next time this happens to see if there is a particular device transmitting constantly and try disconnecting it to see if there is any effect.
Another thing you can do is download a copy of Ethereal, which is a free packet sniffer and see what's happening on the network when the problem occurs. You'll need to have some knowledge on packet sniffers if you're to examine the network packets, so if you haven't used one before, ask a friend to lend you a hand. If you like more information on switches, hubs and other devices that might be the cause of your problem, you can visit www.Firewall.cx where there is an extensive analysis on these technologies.
Related Q&A from Chris Partsenidis
Expert Chris Partsenidis offers guidelines for a smooth and successful PSTN to VoIP migration.continue reading
What SIP trunking basics should you know before you deploy? SIP trunking guru Chris Partsenidis explains what you need to know about SIP trunking ...continue reading
There are many new network security devices on the market today. Expert Chris Partsenidis opines on whether these can replace firewalls.continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.