slooooow modem speed

[dishawjp]

Hi All,

On Sunday I put another hard drive in my youngest daughter's computer and set it up for dual boot with WinXP and Red Hat 9. Overall, the install went well, but there are a few problems. Right now the biggest is a very slow modem speed... around 900B/sec. We're doing an "apt-get dist-upgrade" and have about 8 or so hours into it with another day and a half to go

Needless to say, this isn't acceptable. The modem is an external Zoom 56k modem that used to work perfectly with my old RH 6.2 computer. It's connected to Stty0 and seems to be otherwise OK. The "RD" LED stays lit constantly and the "TD" LED seems to be flashing normally. Is there anything in port configuration or anything else that anybody can think of that would cause this? If so, how do I get at it? I've never had to mess with an external modem before... it was always just "plug and play" which is why I generally use them.

The computer is an HP 521c, 512 MB RAM, 60GB hda, 40 GB hdb, AthlonXP 1.8 processor, and etc.

Thanks in advance for any assistance!

Jim Dishaw

[Calum]

did you set the serial port speed to 115200 baud or whatever it's supposed to be?

in rh9 i think you can do this in either neat or redhat-control-network (sorry GUI programs, if you find the CLI way let me know)

[Void Main]

Yes, I agree with Calum. Make sure your port speed is set as high as it will go. Other than that all I can say is that my dist-upgrades only take a minute or less. But then my modem will do 1.5Mbps. :)

[dishawjp]

Thanks Calum and Voidmain!

I solved the problem. I ran neat and found that the modem baud rate was set at 460800 (pretty high for a 56k modem) and that flow control was turned off too. I reset the modem baud rate to 57,600 and set flow control to "hardware" and now everything is happy.

I didn't see where in that program I could configure the port speed though. It's not an issue for me this time, but could be in the future. If one of you could tell me what tab to click on to configure that, I'd appreciate it.

Calum, you asked about a CLI way to do this. When I typed "neat" into a terminal window to start the program, it was kind enough to print a lot of data to the terminal. Messages about modem configuration mostly, as far as I could tell. I grabbed some of that and started "grepping around" in the /etc directory and found the /etc/wvdial.conf file which was just about a perfect match for the output to my terminal window from running neat.

I didn't have any time last night to play around with it much; I was more concerned eith getting my daughter's computer fixed, and really don't expect to have any free time until this weekend. But when I get a couple of hours to just play around I'll experiment with editing the wvdial.conf file and see if the changes can be effected that way. I'll let you know when I do.

Oh, while poking around in there I also found that "stupid mode" was set to "1" on both my daughter's and my computers. I guess that means that the modems are running in "stupid mode." I suppose that's appropriate in my case..., but do either of you have any idea what that means? Just curious.

Jim Dishaw

[Ice9]

Stupid Mode
When wvdial is in Stupid Mode, it does not attempt
to interpret any prompts from the terminal server.
It starts pppd immediately after the modem con-
nects. Apparently there are ISP's that actually
give you a login prompt, but work only if you start
PPP, rather than logging in. Go figure. Stupid
Mode is (naturally) disabled by default.

More about wvdial here

[Void Main]

A port speed of 57,600 is actually much too slow for a 56k modem. Two 56k modems can actually transfer data much faster than 56k bits per second because the sending modem should be configured to compress data and teh receiving modem should decompress the data. The 56k is the maximum throughput of the compressed data. So more than 56k of data per second will be going to the modem through the serial port depending on the compressibility of the data that you are transferring. Text data compresses nicely and you should get around 10 to 1 compression rates where a *.gz file will only get a 1 to 1 compression rate.

I used to use the "setserial" command to set the port speed on old versions of Linux but I have to admit that I haven't set up a modem in a long long time so I don't know if setserial or other commands are used to set the port speed. You should be able to create a /etc/rc.serial as Red Hat automatically checks for this file. If you have setserial installed you should have a sample rc.serial file under the /usr/share/doc/setserial-2.17 directory. But again, this may not be the preferred method any more. I haven't checked the Red Hat manuals yet to see if there is a better way. Ethernet is soooo much easier (and faster).