pbiron@weber.ucsd.edu (Paul Biron) (08/01/90)
Hi, I'm just about ready to pick up my new NeXT and I need a modem to go along with it. The two that I've been looking at are the Telebit T1000 and T1500. However, I know didly-squat about modems and need a little advise. What I need to be able to do with this modem (at least for right now) is dial-up some local (and remote) UNIX systems, handle UUCP, and possibly SLIP. From the documentation I've been able to get ahold of, both modems will be able to do this. However, the T1000 does not do V.32, whereas the T1500 does. The question I have is: what will I be missing if I don't have V.32 capabilities? Thanx for any advice, Paul Biron pbiron@ucsd.edu (619) 534-5758 Central University Library, Mail Code C-075-R Social Sciences DataBase Project University of California, San Diego, La Jolla, Ca. 92093
tnixon@hsfmsh.UUCP (Toby Nixon) (08/03/90)
In article <2693@network.ucsd.edu>, pbiron@weber.ucsd.edu (Paul Biron)
asks:
- The question I have is: what will I be missing if I don't have V.32
- capabilities?
If you get the T1000, the maximum speed you'll be able to
communicate with other than Telebit modems is 2400bps. With V.32,
which is the international standard for modulation at 9600bps,
you'll be able to communicate at that speed with modems from all
other modem manufacturers. For just a little bit more money, the
number of modems you can communicate with is multiple by 50 times or
more! While most manufacturers have proprietary modulation schemes
that offer some kind of advantage over V.32, they can only
communicate with other modems from the same manufacturer. For the
maximum flexibility and connectivity, you need to have V.32.
-- Toby
-----------------------------------------------------------------------------
Toby Nixon, Principal Engineer Fax: +1-404-441-1213 Telex: 6502670805
Hayes Microcomputer Products Inc. Voice: +1-404-449-8791 CIS: 70271,404
Norcross, Georgia, USA BBS: +1-404-446-6336 MCI: TNIXON
Telemail: T.NIXON/HAYES AT&T: !tnixon
UUCP: ...!uunet!hayes!tnixon Internet: hayes!tnixon@uunet.uu.net
MHS: C=US / AD=ATTMAIL / PN=TOBY_L_NIXON / DD=TNIXON
-----------------------------------------------------------------------------pbiron@weber.ucsd.edu (Paul Biron) (08/14/90)
In article 5424 of comp.dcom.modems <2693@network.ucsd.edu>, I wrote: >I'm just about ready to pick up my new NeXT and I need >a modem to go along with it. The two that I've been >looking at are the Telebit T1000 and T1500. However, >I know didly-squat about modems and need a little advise. >What I need to be able to do with this modem (at least >for right now) is dial-up some local (and remote) UNIX >systems, handle UUCP, and possibly SLIP. >From the documentation I've been able to get ahold of, >both modems will be able to do this. However, the >T1000 does not do V.32, whereas the T1500 does. The >question I have is: what will I be missing if I don't >have V.32 capabilities? >Thanx for any advice, Thanx to everyone who replied (both directly by e-mail, and to this group) to my question comparing Telebit T1000's to T1500's. This is a summary (kind of long) of the responces that I recieved. Many people pointed out the obvious: since T1000's are PEP modems (Telebit propriatary protocall) they will only be able to talk to other PEP modems at 9600 bps, and T1500's are v.32 modems (industry "standard" protocall for 9600 bps) so they will be able to talk to other (supposedly greater in number) v.32 modems. Several people pointed out that ~80% of UNIX machines out there have Telebit TrailBlazers (which use the PEP protocall and v.32 as well) and 100% of the machines that I want to connect to *RIGHT NOW* are UNIX machines *WHICH DO HAVE* PEP modems and I can't imagine (I know, I should be more imaginative, but... :-) wanting to connect to other systems (such as DOS or Mac BBS's), then not having the industry "standard" v.32 is no problem. I got one reply from someone at Telebit, who explained at little bit about PEP itself, and specifically about Telebit's and SLIP. The jist of his message was that Telebit's don't handle SLIP very well -- it causes thrashing between small and large packets, so their modems spend too much time merely switching between packet lengths and not enough time actually sending data. However, there are 2 pieces of *good* news about SLIP. The first is that Telebit (or someone they've donated a mass of TB's to) is working on ways to improve their performance on SLIP [I forget offhand if the reply from Telebit was via e-mail or to the net, if anyone wants info on this research, let me know and I'll send it to you]. The second piece of *good* news is not really good news at all :-( Apparently, there is some problem running SLIP on the NeXT at all. I don't really understand the actual problem (there was a thread going in comp.sys.next about this last week) but it has something to do with MACH (the OS on the NeXT) and the ability (or lack thereof) to transfer data between kernel and user space. So, at the moment, it looks like Telebit's poor performance on SLIP is really a non-issue for me. Things that I found out one my own are that both the T1000 and T1500 are "crippled" T2500's. That is, Telebit they are actually TrailBalzers (or TB+'s) which have been rigged to only handle PEP or v.32 for high-speed transfer (as well as cutting off that high-speed at 9600 bps, instead of the TB's 19200 bps). So if I could afford a T2500 I get that...but I can't. Also, none of the replies mentioned other manufacturors modems (I know a was only comparing T1000 to T1500, but I sort of expected replies mentioning USRobotics, etc). I have been told that Telebits are better on "noisy" lines that USR's. Lastly, some "features" of the T1500 that are absent from the T1000: password checking and security callback (i.e. when someone connects to a T1500, it will call a specified number back to verify that the incomming call is authorized). I don't require either of these "features", though they may be important for others. In summary, I've desided on the T1000 for three reasons: 1. Most (if not all) of the machines I want to be able to connect to will have PEP modems 2. The price is right! 3. I don't *NEED* any of the other "features" of the T1500. Thanx again to all who replied, Paul Biron pbiron@ucsd.edu (619) 534-5758 Central University Library, Mail Code C-075-R Social Sciences DataBase Project University of California, San Diego, La Jolla, Ca. 92093