Baslinux mailing list

[sindi keesan <keesan AT sdf.lonestar.org>]

On Wed, 28 Dec 2005, sindi keesan wrote:

> I checked my internal non-USR modem and my external 1997 USB Sportster
> (upgraded to V90) at both 115200 and 57600 connect speeds.
>
> Non-USR connects at V90 with MNP/MNP5

In eznet.conf I had been giving this non-USR modem the same init string
as my USR modem, and it apparently turns MNP on instead of off to tell it
S15=128 (and does not speed up the login process to tell it S32=34, which 
for USR skips X2 and goes straight to V90 but this one boings for much 
longer.)

I simplified to AT&F1 and now this modem connects with LAPM/V42BIS like
the USR.  They are both 50666 upload speeds.

> USR uses V42BIS and LAPM
>
> Non-USR takes 2 min 20 sec to Kermit FTP upload a 180K file.  It starts
> off at 10K, then 25K, then a big pause, then gradually decreases speeds to
> 4K, 3.3, 2.7, 2.5, 2.3, 2, 1.96 1.88 1.84, 1.80 and there are big pauses
> after each time it switches speeds, so that the final average speed is
> 1340 CPS.  Same behavior at both connect speeds.
>
> The USR modem takes 50 sec to upload the same file, slowing to about 4K by
> the end, also with long pauses, and the average speeds are for 57600
> connect 3040 CPS and for 115200 3221 CPS.
>
> So I still have some problem but less severe.
>
> For USR I have disabled MNP with S15=128 but I think that may be specific
> to USR Sportster.  I will try it anyway with the other modem.
>
> Sindi

The non-USR modem, with the proper init string and V42BIS instead of MNP, 
has the same stalling problems but is going much faster, and uploaded the 
same file at average speed 3151 instead of 1340 CPS.  (There is still 
about a 20 sec wait at the end using Kermit file transfer or Kermit FTP, 
with nothing obvious happening).  Can I do much better with 50666/31200
speed?  The USR peak speed V90 was 53333 (download).  Maybe there is some 
way to tell Kermit not to send too fast to the modem.  I bought the book.

So I have doubled my upload speed by using the right init string for each 
modem.  (Why can't they standardize?).

I checked out the modemsite troubleshooter and it said if I have frequent 
stalls to try a slower connect speed.  The port speed does not seem to 
affect uploads since it is faster in either case, but would it slow my 
downloads to use 57600 instead of 115200?  Another day's experiment.