How do I disable a) Retains, and b) MNP 2-4 Compression?

My modem info:
Internal USR V92 Performance Pro.
Model Number: 5610B

Thanks,

Bob

Bob wrote:
a) Retrains will stop when you have a stable connection. If you are
getting retrains, then try lowering your connection top speed, until it
becomes stable. Do that by using the &Uxx&Nxx in the DUN Extra Settings
box. For example, to set a range of speed 19,200 to 45,333 use &U10&N30.
If your 56k connections are normally lower than 40,000, you would
probably be better off using V.34 with a max speed of 33,600. V.34 is a
very stable mode, and in some cases, will provide better overall
throughput than low speed V.90/92 type connections. To disable all 56k
type connections in your modem, add S32=226 in Extra Settings. Another
thing that can cause retrains, is failing to disable Call-Waiting on
your line, if it has that feature. An incoming call would interrupt the
data carrier, causing a retrain, or a disconnect in some cases.

b) Hmmmmmm, that's a question I can't answer specifically. The S15
Register is used to disable various compression/correction modes. Why
would you want to disable compression? That would slow down throughput.
Is there some specific problem you are having, or some special type
setup that you are trying to achieve? If you could give details, maybe
we could help more. You can download a User Command Reference at this link.
http://www.usr.com/support/5610b/561...5610b-user.pdf
Good luck.

--
Art Jackson W4TOY Owensboro, KY USA
Life is God's open book test. In order to pass,
you must open His book to find the answers.

Thanks for the link to the manual, and the speed limitation suggestion.

Here's my final extra AT commands, and an explanation of each command:

My Init String:

&U26&N30&K3S10=30S11=20S15=127S27=4S28=0S32=130

This init string is for the USR 56K V92 Performance Pro. The commands are in
addition to what the driver sends to the modem
(AT&F1E0Q0V1&C1&D2S0=0S6=8S7=60S19=0L0M1&M4&K1&H1& R2&I0B0X4 - The default
Hardware Handshake option in the USR ControlCenter application).

With my init string, I consistently and reliably connect at 45.2K. From
starting the dialling to being authenticated takes 35 seconds. My O.S. is
Windows 2000.

Detail:
======

Minimum connect speed:
&U26 40,000 bps

Maximum connect speed:
&N30 45,333 bps

Disable MNP5 (laggy) compression:
&K3 V.42 bis only

Improve line noise immunity (default is 1.4 seconds):
S10=30 3.0 seconds no carrier immunity

Dial pulse duration & spacing (default is 70ms):
S11=20 20ms

Disable MNP (laggy) compression:
S15=127 Disables MNP for all modulations.

Disable retrains:
S27=4 Disables V.21, V.23, and V.32

Disable V.32 answer tones (faster connect):
S28=0 Disables V.32

Disable V.92 modulation (my ISP is V.90 max):
S32=130 Disables V.92

With the maximum speed set at 45,333 bps, I no longer get retrains. Still, I
have disabled the unwanted modulations, as I would prefer to disconnect and
then re-connect should the line/connection quality drop.

Wherever I read about boosting modem throughput I see a recommendation to
disable MNP, as it is 'laggy'. Having said that, I don't think MNP is ever
used when I connect to my ISP, but I disabled it anyway, just in case.

Bob



"Art Jackson" <nospam@ringading.buz> wrote in message
news:1ks1d.56664$Np2.51821@bignews4.bellsouth.net. ..

Bob wrote:
There is a lot of unnecessary stuff in your Extra Settings, IMHO. Just
for kicks, try &U26&N30S32=130 and see if you don't get the same
results. Let me know. Good luck.


--
Art Jackson W4TOY Owensboro, KY USA
Life is God's open book test. In order to pass,
you must open His book to find the answers.

On Fri, 17 Sep 2004 21:19:22 -0500, "Bob" <AbbyNormal@hotmail.com> put
finger to keyboard and composed:

I'm using MNP for error correction and V.42bis for data compression.
My old ISA Rockwell modem connects at 48000bps and maintains solid
throughput at this speed. If I revert to V.42 EC and V.42bis
compression, then my throughput drops to 46667bps or less. I don't
know why this should be the case, but I suspect it is due to a
beneficial firmware bug or quirk.


- Franc Zabkar
--
Please remove one 's' from my address when replying by email.

I tried '&U26&N30S32=130' as you suggested, and my connect speed and
throughput were the same as with all the other 'extra' AT commands (connect
speed 45.2K, and throughput of 5.2K). There was, however, a noticeable
increase in connect time, slower dialling and longer negotiation. Further
testing has shown that S11=20 and S28=0 do indeed reduce the connect time.
So, the minimum extra AT command set that I will be using is:

&U26&N30S11=20S28=0S32=130

I'm in a rural location and having read some of the connect speeds that
others are getting, I don't have much to complain about. Although, I do
suspect that my ISP has capped the max speed at 45.2K!

Bob


"Art Jackson" <nospam@ringading.buz> wrote in message
news:rmO2d.74434$Np2.59974@bignews4.bellsouth.net. ..