Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!apple!netcom!gandrews
From: gandrews@netcom.COM (Greg Andrews)
Newsgroups: comp.dcom.modems
Subject: Re: T2500's and v.32bis -- rumors?
Summary: Not on the T2500 platform.
Message-ID: <28407@netcom.COM>
Date: 15 Mar 91 18:55:07 GMT
References: <1991Mar14.061634.14390@shaman.com>
Organization: Netcom - Online Communication Services  UNIX System {408 241-9760 guest}
Lines: 65

In article <1991Mar14.061634.14390@shaman.com> jiro@shaman.com (Jiro Nakamura) writes:
>
>Has anyone heard anything about whether Telebit will start supporting
>T2500's with v.32bis? I bounced a message off modems@telebit.com and
>this is what they said:
>
>  [contents deleted - they said a new modem would be available this year]
>
>	:-(   I wonder what type of upgrade it will be. Does the 68000 in
>the T2500 have enough horsepower to run v.32bis? Or maybe the DSP chip?
>Hmmm.....

No.  That's also the reason PEP hasn't been updated much in the past
two or three years.

>	I hope I haven't gotten techie in trouble, BTW. (Chances that 
>Telebit reads USENET are... ?)  

Nah.  The tech didn't reveal anything he wasn't supposed to.  The chances
Telebit reads Usenet in an official capacity are low, but a couple of folks
contribute from their own private accounts.  (blush)

>I do hope that we can get v.32bis and cheaply. Telebit *should* show the 
>world that it is totally behind CCITT standards. I also think that PEP 
>needs a little boost and should become full duplex. 

If Telebit weren't interested in CCITT standards, there wouldn't have
been a T2500, T1500, or T1600.  As modems@telebit.com said, a V.32bis
modem is forthcoming - it just won't be the T2500.

>	If Telebit gets UUCP spoofing running over v.32bis with v.42bis
>(just as it already runs over v.32 with MNP (why not v.42bis????)), then
>I don't see that PEP will remain a viable communications standard unless
>it gets upgraded. Who knows? Maybe Hayes or USRobotics will finally wake
>up and start doing protocol spoofing on their own. 
>	

Why no protocol spoofing in V.42?  Simple - the CCITT wasn't registering
extensions to the V.42 protocol when Telebit wanted to add protocol support.
Microcom was willing, so it was implemented in MNP mode.  There are some
"unregistered" extension codes available, but only at the risk of colliding
with someone else's private V.42 extension...  Telebit will keep checking
with the CCITT so spoofing can be added to V.42 mode also.

It's been pointed out before that a windowed protocol like uucp doesn't
really need spoofing when you're running a full duplex modulation.  Uucp
spoofing doesn't gain much in the way of speed over V.32 or V.32bis links
the way it does over PEP.  Still, there are advantages in other areas.
The modems can disable an inappropriate flow control method (XON/XOFF)
when the spoofing modem kicks in, solving those types of problems.  Error
recovery can be quicker, since the modems handle the error in the link
protocol (MNP) rather than the computers dealing with it at a higher level.
This means a broken packet may not need to have that packet **and all the
rest of the packets in the window** re-transmitted across the phone line,
saving time.

Protocol spoofing over a full duplex modulation will help the most with the
old stop-and-wait protocols like Xmodem, Ymodem, and the original Kermit.
Spoofing can make those protocols run as fast as windowed types.


-- 
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| Greg Andrews      |   gandrews@netcom.COM |
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