Heya,
Basically switches have some considerable advantages or swtiches(provided that they arn't completely swamped). With HUBs data is sent from one port, and then the HUB brodcasts(sends to everyone)the data down every single port on the HUB, even if the data doesn't need to goto that port(this enevitably creates collisions). With switches the data is sent from one port and only is sent to the port that it is intented for, so this makes switches faster(and more secure).
But(yes there is always a but...).Switches switch in 2 ways, "cut through" and "store and foward", with cut through the switch reads the header(which contains the address of the computer the data is going too) and just fowards the data straight there, without verifying if the data is corrupted or not, this is very fast and under normal load is faster than HUBs. Store and Foward mode is where the switch reads all of the data and verifys its integrity before fowarding it on to the computer, this is still fast, but slower than "cut through", what happens on a switched network when it come under heavy load is that the swtich has an "error threshold" it will change from "cut through" to "store and foward" which slows the network down. "Store and foward" mode has a que in which data is qued up to be verified before being fowarded on, sometimes under heavy load this "que" becomes full and then the switch can slow down. Switches, such as cisco ones(And others I think), come with built-in "backoff" and other features that reduce this problem greatly but forcing the "que" to process the data faster.
Before you change I would look at the current needs of your network, is it running slow? could it be faster? are you reciving complaints from users? Then I would look at where your company(the network always follows the company..) is going in the next few years, if you are hiring more people and growing then you will require more bandwidth. Personally I would recommend switches, they are faster and more secure, and the performance increade will be quite noticable.
Hope this wasn't confusing and too much information...I have a nasty habit of phrasing things badly. As to the Network Monitoring software I cant think of any, sorry.
Nathan
