Externel Serial modem is slow

Likosin · 01-26-2005, 05:58 PM

I just bought an external 56K serial modem (Best Data 56SX92) to replace my old, crappy internal pci winmodem because it liked to randomly disconnect me. But, my new modem (I tell KPPP the device is ttyS0) is significantly slower: 0.5KB/s, instead of a normal 4.0KB/s. Could this be a kernel misconfiguration? Any insights or suggestions are appreciated!

-Thanks

michaelk · 01-26-2005, 06:54 PM

It might be a misconfiguration. Using minicom or gcomm app you can see the modem's setup via the at&v command. Does the modem manual happen to list the at commands? Is ttyS0 configured for the highest baud rate?

Likosin · 01-26-2005, 07:13 PM

I can connect to the modem (but not with minicom, with KPPP's built in console.) 'AT &V' prints a whole bunch of numbers which I can't make sense of. The manual has some basic modem commands, and tells me that 'AT +MS=V92' will set the speed to 56K, and use the V.92 standard...where would I add this (preferably with
KPPP)? How do I set the serial port's baud rate? Should I set it to 56000? Thanks for the info!

michaelk · 01-26-2005, 08:13 PM

Does kppp have any device settings? Set the baud rate to 115200.
There should be a modem tab to configure any at commands to send to the modem. It has been a long time since I've had to mess with modem settings.

Likosin · 01-26-2005, 09:06 PM

It does have device settings, and 115200 is an option, but so is 460800, which is higher. Is there a reason I shouldn't use 460800? KPPP also gives me the option of specifying a second initialization string, I set this to 'AT +MS="V92"', but the manual all recommends sending '+MR=2'...how do I combine these two?
Thanks so very much for all the help!

michaelk · 01-26-2005, 09:15 PM

The baud rate depends on the modem capablilities. Try and see.
Its been such a long time since I've played with modem settings I will have to check to make sure.

Likosin · 01-26-2005, 09:21 PM

Hmm, I tried putting AT +MS=V92' in my initialization2 string, it didn't help, the modem was still slow. Also, should I be using software flow control, hardware flow control, or none? For reference, the AT set for my model is at http://www.bestdata.com/tech/v.92CommandReference.pdf
Thanks in advance!

HalfDiminished · 02-04-2005, 09:28 AM

Likosin,
Have you had any luck? I have the same problem. My external TrendNET-560X modem was working fine until I re-installed Debian Sarge. Now I can't get it to go over 9600 baud. I've tried setting the baud rate with wvdialconf then editing /etc/wvdial.conf, also I've tried the modem tabs in kppp and GNOME-ppp. Still wvdial reports CONNECT 9600 and it is slow as heck.

Likosin · 02-04-2005, 02:42 PM

Unfortunately, I've gone back to using my fast-but-unstable internal modem. I'll play with my external one some more, I'll let you know if I am in any way successful. If you come across anything else, please let me know.

Thanks!

Likosin · 02-04-2005, 10:22 PM

Well, I think i got it working, I finally payed attention to one of michaelk's posts above, and set the rate to 115200 instead of 460800...now it works fine. Let me know if this helps!

HalfDiminished · 02-07-2005, 09:20 AM

Likosin,
As it turns out, the init string set up by wvdialconf by default was not correct for my modem. I had to get rid of the FCLASS=0 string and everything is working fine now. FYI- here is a great site for modem inf - including init commands.

modemhelp.net/quickref.shtml