From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Cross Message-Id: <200111212001.PAA22302@augusta.math.psu.edu> To: 9fans@cse.psu.edu Subject: Re: [9fans] on TCP vs IL In-Reply-To: <20011121010744.C4DBB19A46@mail.cse.psu.edu> Cc: Date: Wed, 21 Nov 2001 15:01:51 -0500 Topicbox-Message-UUID: 26e7b618-eaca-11e9-9e20-41e7f4b1d025 In article <20011121010744.C4DBB19A46@mail.cse.psu.edu> you write: >TCP is usable over long and short networks. IL is usable only over >short networks. If I had to pick just one, guess which one I'd use? >Wouldn't you rather use the general solution than the specialized one? A chainsaw will cut both butter and trees. A butter knife will cut both as well, but will be very much less efficient cutting down a tree. If I had to choose only one.... I'd probably pick the chainsaw so as to also be able to terrorize those who ask such silly rhetorical questions. :-) The analogy is strained, perhaps, but apropos. il seems like the buffer knife. It's great for cutting butter. TCP is like the chainsaw, it's great for cutting down trees (and terrorizing half-naked coeds in B flicks), but makes a huge mess when buttering your toast. What ever happened to the right tool for the job? Is il just too much of a maintenance hassle so as to be not worth it for local area networks? (And no, I've never terrorized anyone with a chainsaw, nor would I. :-) >TCP is probably only slightly less efficient on the wire than IL. I've read differently; see below. >TCP has all that baggage, yes, but it won't get used on local >ethernets unless the net is in big trouble. Some of that baggage gets used no matter what (all the window size negotiation stuff, for instance). >I have no numbers to back up my ``only slightly less efficient'' >assertion. But then, you haven't presented any numbers either. Of course I didn't post any numbers; I was asking a question. If I'd already known the answer, why would I have asked? :-) But since you brought it up.... Once, I sat down on a Saturday (it was raining) and I read the entire 9fans archives. Contained there in was a detailing of someone's experience running Plan 9 over a 10Mbps Ethernet. When using IL, they used up something like 30% of the available bandwidth to move data at some rate. When they switched to TCP, bandwidth utilization jumped up to something like 80%. Granted, that's on a much slower form of Ethernet than what's commonly used today, and the TCP implementation has been much improved, but one gets the impression that IL requires rather less overhead than TCP. Unfortuantely, since PSU's Computer Science department has seen fit to put the 9fans archives on an SSL protected web server that I can't talk to using the only computer I have net access on right now, I can't look up the exact citation. :-( >Local networks are fast enough that it just doesn't matter. Fair enough. - Dan C.