Xref: utzoo comp.sys.mac.comm:4178 comp.sys.mac.wanted:4029 Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!rice!uw-beaver!zephyr.ens.tek.com!tektronix!reed!rbrewer From: rbrewer@reed.edu Newsgroups: comp.sys.mac.comm,comp.sys.mac.wanted Subject: Re: SUMMARY: PM9600SA modem and Practical Peripherals Summary: baud not same as bps Message-ID: Date: 10 Jun 91 16:34:05 GMT References: <0E010021.00p3xj@gla-aux.uucp> Sender: nobody@reed.UUCP Reply-To: rbrewer@reed.bitnet (Robert S. Brewer) Followup-To: comp.dcom.modems Organization: Reed College, Portland, OR Lines: 38 In article <0E010021.00p3xj@gla-aux.uucp> glenn%gla-aux.uucp@skinner.cs.uoregon.edu writes: >In article <1991Jun4.194525.14503@bronze.ucs.indiana.edu>, tagreen@lothario.ucs.indiana.edu (Todd Green) writes: >> >> Is this a real 9600 baud carrier modem, or is it just a 2400 with thur-put >> >> up to that of arround 960 cps?? >> I cannot believe that it is 9600 baud. I would assume that it is 2400 >> baud carrying 4 bits per signal change. (Hence 9600 bps) Add MNP5 and >> you get 19.2Kbps (with 2:1) compression. Add v42bis and you get 38.4K >> (with 4:1) compression. How do you other people arrive at 9600 baud? > >Yes, it IS a true V.32/V.42bis 9600 baud modem. Where have you been over >the last year and a half while the V.32 protocol was being (rather loudly) >announced? > >| Glenn L. Austin | "Turn too soon, run out of room. | >| Usenet: glenn@gla-aux.uucp or glenn%gla-aux.uucp@skinner.cs.uoregon.edu | I think we are having the classic "baud vs bps" problem. Back when we had 300 baud modems, the baudrate was equal to the number of bits per second (bps). Baud refers to the number of state changes per second, and it is NOT the same as the bps. It happened to be the same for early modems, so people got in the habit of using the word 'baud' instead of 'bps'. The point that Todd appears to be making is that there is no such thing as a 9600 BAUD modem. A modem using V.32 is 9600 bps, not 9600 baud. The confusion comes in with 2400 bps modems that have MNP5 or V.42bis. These allow compression, and therefore in some cases can make actual throughput (number of bytes stored on your disk) higher than 2400 bps. The manufacturers' often claim that their modems run at 9600 bps (or even worse 9600 baud!), which is not true. They may give you better throughput on some (noncompressed) files, but they are certainly not 9600 bps modems by any stretch of the imagination. The moral of the story is: don't use the word baud unless you really have to. 'bps' is almost always the 'right' choice. I have redirected follow-ups to comp.dcom.modems as this is getting pretty un Mac-related.