[comp.sys.mac.comm] Should I get MNP5 or V.42bis?

das@Apple.COM (David Shayer) (09/14/90)

I'm going to be buying 2 9600 bps modems, so my partner and
I can send files back and forth.  I want to get data compression,
but most companies seem to offer V.42bis OR MNP5.  Which is
better?  Which one is the world going to go?  I don't want
to buy the system that is going to obsolete next year.

I would also welcome any advice on which modem to get.
I'm currently looking at the Intel 9600EX, which has V.42 and
V.42bis.  The list is $819, but mail order its only $549.

Any help would be appreciated.

David

an12280@mdaali.cancer.utexas.edu (David Gutierrez) (09/14/90)

In article <44782@apple.Apple.COM> das@Apple.COM (David Shayer) writes:
> I'm going to be buying 2 9600 bps modems, so my partner and
> I can send files back and forth.  I want to get data compression,
> but most companies seem to offer V.42bis OR MNP5.  Which is
> better?  Which one is the world going to go?  I don't want
> to buy the system that is going to obsolete next year.

We got a pair of Hayes Ultra Smartmodem 9600 modems for about $800 each 
from Dr. Mac in Sherman Oaks, CA (check MacWorld for their ad). These 
modems offer V.42bis *and* MNP5 (it says here). If you do order from them, 
be careful that you get the *Ultra* version. The sales people just see 
cardboard boxes.

David Gutierrez
an12280@mdaali.cancer.utexas.edu

"Only fools are positive." - Moe Howard

newbery@rata.vuw.ac.nz (Michael Newbery) (09/17/90)

X.42bis includes MNP5 as a subset. Any implementation confirming to
X.42bis *has* to also support MNP5.
Similarly for X.42, which includes MNP3 as a subset.

Conclusion: get X.42bis.

--
Michael Newbery<newbery@rata.vuw.ac.nz>
Ah! I see you have the mind that goes "ping!"

russotto@eng.umd.edu (Matthew T. Russotto) (09/18/90)

In article <4106@lib.tmc.edu> an12280@mdaali.cancer.utexas.edu (David Gutierrez) writes:
>In article <44782@apple.Apple.COM> das@Apple.COM (David Shayer) writes:
>> I'm going to be buying 2 9600 bps modems, so my partner and
>> I can send files back and forth.  I want to get data compression,
>> but most companies seem to offer V.42bis OR MNP5.  Which is
>> better?  Which one is the world going to go?  I don't want
>> to buy the system that is going to obsolete next year.
>
>We got a pair of Hayes Ultra Smartmodem 9600 modems for about $800 each 
>from Dr. Mac in Sherman Oaks, CA (check MacWorld for their ad). These 
>modems offer V.42bis *and* MNP5 (it says here). If you do order from them, 
>be careful that you get the *Ultra* version. The sales people just see 
>cardboard boxes.

The latest version of USR's Dual Standard also has V.42bis (in V.32 mode only,
I believe) and MNP5 (in either HST or V.32 mode).  If all you need is V.32,
go for the cheaper one.  However, if you are only transferring files in
one direction at a time (i.e. send one file to him, then he sends one file to
you, etc-- not two files being sent simultaneously), then the HST offers faster
speeds-- up to 14,400 bps, nominally (before compression).  And if you get
the Dual Standard, you will still be compatible with The Rest Of The World
with V.32.

--
Matthew T. Russotto	russotto@eng.umd.edu	russotto@wam.umd.edu
      .sig under construction, like the rest of this campus.

laird@slum.MV.COM (Laird Heal) (09/18/90)

In article <44782@apple.Apple.COM>, das@Apple.COM (David Shayer) writes:

>I'm going to be buying 2 9600 bps modems, so my partner and
>I can send files back and forth.  I want to get data compression,
>but most companies seem to offer V.42bis OR MNP5.  Which is
>better?  Which one is the world going to go?  I don't want
>to buy the system that is going to obsolete next year.

V.42/bis is better by far than MNP 5.  Sorry, but I do not have any
real-world figures to quote.  I have some comp.dcom.modems articles 
saved off, and if you want to see them, send me mail.

>I would also welcome any advice on which modem to get.
>I'm currently looking at the Intel 9600EX, which has V.42 and
>V.42bis.  The list is $819, but mail order its only $549.

                                      vvvv      vvvv
Let me caution you to look harder for V.32 than V.42.  V.32 describes 
how the data is sent down the wire.  I mean, compressing the data is 
one thing, sending and receiving is another.  V.32 is a full-duplex 
mechanism (both ways at 9600bps per).

There are other 'ping-pong' implementations.  These are for transfers
mostly in one direction at a time.  Telebits have PEP, with 19.2kbps 
the nominal transfer rate.  US Robotics has HST, now at 14.4kbps, and 
there are others like V.29 going one way at at time at 9600bps.

My US Robotics HST-DS has V.32 and HST modulation.  It worked well for 
calling bulletin boards.  Maya had a good price, too.  Compressed data
often transfers at 16.6kbps, as if the HST modems 'play hooky' and drop
the start-stop bits.  I never timed any (MNP 5) text transfers, I just 
zoomed the window in as far as I could so my Portable could keep up.  

I now have the V.42 upgrade kit, but the only V.42 modem I can call is 
a Hayes, which must be the most incompatible high-speed modems around.
Even a Telebit connects decently at 1200-2400, but those V-series Hayes
are trouble even to connect to!  Shucks.  Then again, folks that do have 
a V-series Hayes just won't use anything else...

Telebits are reported to deliver reliable 12k-14kbps on voice-grade
lines.  Ask your uucp administrator.  Yesterday my news feed at 2400bps
took six hours on my HST-DS, so getting a Telebit is on my mind.

>Any help would be appreciated.

- Telebits handle line noise exceptionally well, but turnaround is said 
  to be poor for interactive sessions at high-speed.  They also have 
  protocol spoofing, which I will not go into here.
- The US Robotics HST has a great real-world transfer rate when the lines 
  are clean and is also better interactively, "due to more bandwidth on 
  the back-channel", or so it is said. 
- Both of the above are 'ping-pong' half-duplex modems where the direction
  of high-speed transmission is allocated according to requirements.  You
  might desire two-way transmission, as for Async AppleTalk or SLIP, and
  that means using V.32 modulation.

I have redirected followups to comp.dcom.modems, where this topic belongs.

-- 
Laird Heal	laird@slum.MV.COM	Talk is cheap.
(Salem, NH)	+1 603 898 1406		Whiskey costs money.

an12280@mdaali.cancer.utexas.edu (David Gutierrez) (09/18/90)

In article <1990Sep17.174250.23448@eng.umd.edu> russotto@eng.umd.edu 
(Matthew T. Russotto) writes:
> The latest version of USR's Dual Standard also has V.42bis (in V.32 mode 
only,
> I believe) and MNP5 (in either HST or V.32 mode).  If all you need is 
V.32,
> go for the cheaper one.  However, if you are only transferring files in
> one direction at a time (i.e. send one file to him, then he sends one 
file to
> you, etc-- not two files being sent simultaneously), then the HST offers 
faster
> speeds-- up to 14,400 bps, nominally (before compression).  And if you 
get
> the Dual Standard, you will still be compatible with The Rest Of The 
World with V.32.

The reason we bought the Hayes Ultra 9600 modems is that when talking to 
like-minded modems (V.32, V.42, V.42bis) they can transfer at 38,400 bps, 
not 9600. Of course, I only got to play with them for two days, then we 
had to put them on my section chief's Sun and PS/2.

Again, the warning: make sure you specify the *Ultra* Smartmodem. Hayes 
also sells the "not really V.32, but we're going to call it V.32 anyway" 
modem that uses proprietary Hayes protocols incompatible with the actual 
V.32 standard.

On the other hand, the latest MacWeek (11 Sept., p.14) says that Intel is introducing a similar modem that *retails* for $819. If you can wait a couple of weeks until they're readily available, I'll bet you can get a really good deal on a pair of those.

David Gutierrez
an12280@mdaali.cancer.utexas.edu

"Only fools are positive." - Moe Howard

blood@aludra.usc.edu (Brian Blood) (09/25/90)

From blood Mon Sep 24 20:19:03 1990
To: /home/chaph9/blood/.article


The modem I would suggest is the Hayers Ultra Smartmodem 9600 which supports
just about every sdtandard there is a known to man. It really doesn't matter
that much which one (v42bis or MNP5) (IMHO) if the main thing you are going to 
do is trandsfer files between the two of you. Both standards are supported by
lots of diiferernt wait, rented fingers...... different modems. Most of your
mainstreeanmn modems support v42bis but lots support MNP5. 
The Hayes Ultra is around 799$799 if you look in the right places.
I am not an expert, just relying on my experiences with BBS's and my job.-->supporting Appletalk network via modem.
BYE. BYE.
Bri.