External 56k Serial Modem Is Slow

I have a Dynalink V1456VQE external serial modem that gets about 36kbs max with openSUSE. However the same modem gets 46kbs when knoppix 3.3 is loaded. Everything else is the same. Can anyone give me some hints as to how to get the same speed under openSUSE. Thanks.

Are you measuring the download speed with the same tool for both distros? Is your modem connected by usb or serial port (with UART chip)? Only if you are using the latter, could this be rate limiting a slow 56k modem. It is a long time ago that I ever had to configure a serial port, but you can do this with the 'setserial' command.

Some info here:

http://www.linuxselfhelp.com/HOWTO/Modem-HOWTO-14.html

http://www.56k.com/trouble/connect.shtml

Edit: Similar thread I found:

http://forums.suselinuxsupport.de/index.ph...mp;#entry182137

What I like to do with my modem is when I configure it in YAST, make sure the baud rate is set to 11500 or less. I think the default is some ridiculous rate like 400000 (which you'll never get anyway) and i have found that for some reason I get much better connection speeds at 11500 or whatever the next lower rate (56000?).

Also if you are using Firefox and go into about:config and disable ipv6 that seems to speed things up as well.

Finally, I find I get better rates with a v92 modem rather than the older v90 models.

Thanks for your info.

It is a serial modem connected to the serial port.

Speed is determined using one of the modem speed sites (involves downloading jpg).

Same PC, telephone line, modem, serial connection, ISP, and the same speed test - only difference is Knoppix 3.3 ~ 46kbs / openSUSE 10.3 ~ 36kbs

I will so some experimenting this weekend and report back. Thanks.

Modem is now up to speed ie max 46k. For those on broadband even 46k must seem very slow but believe you me its speedy compared to 36k

I checked the serial port settings and they seemed to be OK so I made no changes. I decided to reconfigure the Dynalink modem from scratch using Yast. Yast needed some help and I ended up having to make 3 changes.

In the modem config scipt:-
1. Changed device path from '/dev/modem0' to '/dev/ttyS0'
2. Changed speed from 57600 to 115200

In the provider config script:-
3. Changed stupidmodem from 'no' to 'yes'. After making the 2 previous changes I couldn't figure out why I was not getting more than 38k but by changing the stupidmodem line to 'yes' the speed shot up to 46K.

Thanks for everyones help.

For the record here are my 2 main config. files aswell as the serial port settings:

/etc/sysconfig/network/ifcfg-modem0
BOOTPROTO='none'
DIALCOMMAND='ATDT'
DIALPREFIX=''
DIALPREFIXREGEX=''
INIT1='ATZ'
INIT2='AT Q0 V1 E1 S0=0 &C1 &D2 +FCLASS=0'
INIT3=''
INIT8='ATM1'
INIT9=''
MODEM_DEVICE='/dev/ttyS0'
NAME='Modem'
PPPD_OPTIONS=''
PROVIDER='provider0'
SPEED='115200'
STARTMODE='manual'
UDI=''
USERCONTROL='yes'

/etc/sysconfig/network/providers/provider0
ASKPASSWORD='no'
AUTODNS='yes'
AUTO_RECONNECT='yes'
DEFAULTROUTE='yes'
DEMAND='no'
DSLSUPPORTED='no'
IDLETIME='600'
IPADDR=''
ISDNSUPPORTED='no'
MODEMSUPPORTED='yes'
MODIFYDNS='yes'
MODIFYIP='yes'
PASSWORD='mypassword'
PHONE='086712345'
PROVIDER='myprovider'
REMOTE_IPADDR=''
STUPIDMODE='yes'
USERNAME='mylogin'


~>setserial -a /dev/ttyS0

/dev/ttyS0, Line 0, UART: 16550A, Port: 0x03f8, IRQ: 4
Baud_base: 115200, close_delay: 50, divisor: 0
closing_wait: 3000
Flags: spd_normal skip_test

Hmm, wonder what that stupidmode setting does.

For sure changing /dev/modem0 to /dev/ttyS0 does nothing, as the former is just a link to the latter. Upping the serial port speed to the max is a good move anyway.

Hmm, wonder what that stupidmode setting does.

....
[/b]

I think they renamed it to Ignore Prompts in the latest YaST modem setup.

Ignore Prompts disables the detection of any prompts from the Dial up Server. If the connection build-up is slow or does not work at all try this option[/b]

Wow "Stupid Mode". I feel like I am in stupid mode for not suggesting that.

I have experimented with turning that setting on and off but never noticed much difference. However, I have heard some people say it helps, so I should have at least suggested it.

I guess the point is, everyone's set up procedure is going to be a little different, so it is a useful skill to be able to do a little troubleshooting now and then.

Hmm, wonder what that stupidmode setting does.

For sure changing /dev/modem0 to /dev/ttyS0 does nothing, as the former is just a link to the latter. Upping the serial port speed to the max is a good move anyway.
[/b]

In my case I got an error message saying something like "unable to open serial port". Changing the reference to '/dev/ttyS0' fixed it. Go figure.

Well that link is distro dependent and not specified by any standard. I assumed that you meant it was already on your system and you changed it to the actual device to try to improve the speed. My point still stands. Changing the device opened from the actual device to a link to the device has no effect on operation.