A reader—Bandwidth-less in Berkeley—who apparently took a wrong turn at Dear Abby Boulevard, finds his or her bandwidth taxed and seeks a solution. B-liB writes:
My home Internet connection (3 Mbps DSL) has slowed to a crawl. Is there a way I can monitor which applications are eating up my bandwidth?
There is with the help of one of a couple of utilities. Object Development’s $30 Little Snitch, in addition to letting you know when applications are accessing the Internet (and providing you a way to block that access), includes a network monitoring function (found by opening Little Snitch Configuration’s preferences, selecting the Monitor tab, and switching on the Network Monitor option).
In the window that appears you’ll see a list of all the applications that are currently accessing the Internet along with meters next to each one that light up when data is being passed back and forth. The application that’s biting off the greatest portion of your bandwidth appears at the top of the list. (In the case of a Web browser, you’ll also see the specific site that’s currently using the most bandwidth.) So, when your connection is running slow, take a gander at this window to learn where your bandwidth is going. If it's an application you can do without or configure so that it's not hitting the Internet so often (or with such force), make the necessary adjustments.
ProteMac’s $30 ProteMac Meter is a network traffic logger. With it you can not only generate charts of traffic activity (thus looking for spikes and lulls) but also monitor application traffic in real time.
Demos are available for both applications. Download each one and see which is the better fit for your needs.