Subject: (usr-tc) mac's connect at slow speeds

From: David Ernst <[email-masked]>
Date: Tue, 18 Jan 2000 23:17:42 +0000

Does anyone else seem to have relatively consistent problems getting
new Macintosh users to be able to connect at v.90 speeds?  

David Ernst
HoosierNet, Inc.

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From: Howard Reeves <[email-masked]>
Date: Wed, 19 Jan 2000 17:23:49 +0000

I have had lots of problems with the imac. I found the information below on
their website. Hope this helps.

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The iMac modem is the first modem Apple has shipped that supports the new
V.90 protocol. Although derived from the competing x2 and K56flex protocols,
the V.90 specification is in its infancy and will be undergoing changes over
the next several months.

When a modem is attempting to establish a connection with another modem it
will attempt to connect at the highest speed possible. The speed of the
connection is determined by two factors:

1. The capabilities of the other modem:
The remote modem must support the same protocols. The iMac modem supports
both V.90 and K56flex protocols so it can connect to other modems that
support these protocols at speeds between 33.6 kbps and 53 kbps (although
the modem technology is capable of 56 kbps, FCC regulations limit the top
speed to 53 kbps). If the remote modem does not support either of these
protocols, the iMac modem will then try using the V.34 protocol which has a
top speed of 33.6 kbps. The modems will continue to try slower protocols
until they find one that both modems are capable of supporting.

2. Quality of the connection:
Modem connections are being made over regular voice telephone lines. The
quality of a connection between two points can be different each time the
connections is made. Once the modems have negotiated a protocol to use, they
test the ability of the connection to sustain the speed of the connection.
The higher the speed of the connection, the more susceptible it is to noise
on the phone lines. Therefore, even when making a V.90 connection between
the same two points, one connection could be 44000 bps while the other could
be 38000 bps.

If the quality of the connection is such that it can not support the slowest
V.90 connection then the modems will step down to the next protocol.

What we are observing with the iMac modem is this V.90 implementation is
overly aggressive. Instead of negotiating down to support a slower but more
stable connection, the modem keeps trying to connect at a higher speed. This
causes the remote modem to determine that a connection can't be established
and it hangs up.

There are times when this aggressive behavior will manage to complete a
connection, only to be dropped minutes later since the quality of the phone
connection really can not support that connection speed.

The V.34 only modem script is a work around for customers that are unable to
connect using the V.90 protocol. In many cases, even if the V.90
implementation negotiated downward properly, the resulting connection might
end up being between 28.8 kbps and 33.6 kbps due to phone line quality. In
these cases there is no performance difference between using the V.34 and
V.90 protocols.

Apple is working with others in the modem industry to improve the behavior
of the V.90 implementation. The iMac modem is capable of being upgraded via
software.

Currently, modem firmware updates are available from the Apple Software
Updates updates page at: 'http://asu.info.apple.com'.

For additional information on 56 kbps connectivity, see:
Tech Info Library Article 24482: "56Kbps Modems: Getting the Fastest
Connection"

> -----Original Message-----
> From: [email-masked]
> [mailto:[email-masked]]On Behalf Of David Ernst
> Sent: Tuesday, January 18, 2000 3:14 PM
> To: [email-masked]
> Subject: (usr-tc) mac's connect at slow speeds
>
>

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From: Mark Thornton <[email-masked]>
Date: Wed, 19 Jan 2000 17:42:49 +0000

My tech support has reported success with adding additional info to the
initialization string to limit the top end connect speed. This has been very
effective on the PC side, and one of my techs knows how to do it on Macs. I
will try to get the info from him when he arrives and post it.

We ran into this problem with some of the Compaq systems recently. We limit
the top end to about 42000 to start and work up or down from there in a
trial and error method to find a speed that works all the time.

Mark Thornton
San Marcos Internet, Inc.
512-393-5300

----- Original Message -----
From: Howard Reeves <[email-masked]>
To: <[email-masked]>
Sent: Wednesday, January 19, 2000 9:23 AM
Subject: RE: (usr-tc) mac's connect at slow speeds

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From: Mark Thornton <[email-masked]>
Date: Wed, 19 Jan 2000 20:59:45 +0000

Listed below is the info from my local Mac Guru. Hope it helps...

Yup, but it's not trivial. You need to edit the modem script, which 
lives in the modem scripts folder inside the extensions folder which 
is inside the system folder. The modem scripts are just text 
documents, but they have special type and creator codes which you 
must restore using ResEdit or some other such utility.

The easiest way to do this, though is to use Apple's Modem Script 
Generator Utility available at 
<http://asu.info.apple.com/swupdates.nsf/artnum/n10664>. Personally, 
I just edit the scripts manually because I'm a dweeb and like to have 
absolute control over what I'm doing, but the fact is that the script 
generator generates the exact same CCL code that I do except the 
Script Generator's code is commented and mine isn't.

You select the Modem Script in the Modem Control Panel. If all of 
this is too confusing, tell me exactly what you want, and I'll edit 
some scripts for you that you can just pass on to customers.

Apple has some prewritten scripts on their website that limit the 
connection to v.34, but I think that's probably overkill.

In addition, Ross Barkman has written a series of scripts for the G3 
powerbooks, which allow the user to use a trial and error method to 
get the best performance vs stability compromise.

Ross's scripts can be located by doing a search at 
<http://www.versiontracker.com> for Modem Script. This search will 
also point you at a bunch of other script options that may be of use. 
At all costs, avoid Modem Puppet scripts as they don't work in the 
real world.

HTH

Old

Bill Fuller                    

Mark Thornton

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From: Christopher Berry <[email-masked]>
Date: Thu, 17 Feb 2000 21:01:05 +0000

I believe the new macs are using Rockwell chip sets-always problematic for
us and our Hipers and Quads. These modems seem to make a high speed
connection even if it is unstable. My best experience (personal-2 Macs at
home) is to tell the user to change their modem init string (Apple
menu-Control Panel-Modem) to a "(v.34 Only)" version for their modem. Newer
macs and OS versions have these strings included. You can also get them from
Apple and Global Village (Boca Research). The initial connect is slower, but
throughput is much better-fewer retrains and resends I suppose.

Christopher Berry
rof.net Web Design and Technical Support
(970) 945-4920 x17

----- Original Message -----
From: "David Ernst" <[email-masked]>
To: <[email-masked]>
Sent: Tuesday, January 18, 2000 2:14 PM
Subject: (usr-tc) mac's connect at slow speeds

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