com port

[{anonymous}]

ive recently installed a Rockwell v90 56k Voice serial modem, there are properties in device manager under com port 1 which says :-

Flow control : Xon / Xoff or Hardware ? what is this and what does it do ?

and it says bits per second = 9600 - when the modem manual says it can support 115200,

could someone please tell me what they mean, thanks

mike

[Nuclear Krusader]

Well, sure appreciate if someone can shed some lite on dat.

I always leave those options alone (defaults) and just plug the modem and cofigure everything else. I've never had problems with the default settings. HTH

[AlwaysUp]

In device manager, when you highlight your modem>properties>select connection tab and then advanced, if checked in "USE flow control" there will be a radio button for Hardware (RTS/CTS) and a radio button for software(X/ON X/OFF) the default setting will be fine if you have the correct driver for your modem. Most likely your modem is a hardware modem and not a Winmodem and is thus configured. The 9600 can be changed by clicking the dropdown and selecting 115200. It won't connect however at that speed. Your modem will be limited to 56K and will not attain a full 56K no matter what as there is a limit imposed if I'm not mistaken. Your connection speed is much more dependent upon phone line quality and the ways and means of your ISP gatewayto the Internet backbone.

[{anonymous}]

thanks for the reply, but a new problem has arised, with my old modem (Conexant softk56 - winmodem) i was able to get download speeds of 4kb/s + - but since i installed this serial modem, im getting 1.4kb/s, i dont know what the problem is . its very slow downloading .. hope you can help

thanks

[glc]

You need to set the com port properties to 115200, 8, none, 1, hardware.

[Jomama]

The 115200 refers to the port speed not the modem speed.
after a winmodem is set up, often you will see that displayed when you hover over the connection icon in the sys tray.

[{anonymous}]

but why all of a sudden am i getting very low download speeds, when they were high with my winmodem ?

thanks

[glc]

Why? Because you are trying to cram data through a hardware port that is running at 9600 bps and has no (or Xon/Xoff) flow control when your modem is trying to run it through at 40000+ and expects to see hardware flow control. Check your port settings as I indicated. Do this in Device Manager - open the properties of the com port and look on the Settings tab. You didn't have to do this with your winmodem because it used a virtual com port. If this doesn't fix it, post back and tell us the exact manufacturer and model of the modem, and what your indicated connect speed is.

[{anonymous}]

i have set the things you told me to , but still i get 1.8kb/s download. windows says its connected @ 45333 - the modem is
a rockwell - these are the numbers that are on the modem :-

FM56-XT
RCV56DPF L8570A (its plugged into com2)

mike

[glc]

Okay - what we now need to do is try to limit the top connect speed. I KNOW this sounds backwards, but what may well be happening is the modem is connecting too fast for the phone line conditions, this is common behavior with generic Rockwell hardware modems. This will result in a lot of bad packets, which error correction will see and request that the packets be retransmitted, which will kill your throughput. Here is how you do this. Go into the advanced modem properties and look for the Extra Settings box. Put this string in there:

+MS=12,,300,44000

This will limit to 44000, see if your download speeds improve. If they do, go down one more notch and keep trying till you find the sweet spot. The next steps down with V.90 are as follows:

42667
41333
40000

etc.

Note that this string modifier MAY not work with your firmware - if you try it and it doesn't connect at all or connects faster than 44000, try this one:

+MS=V90,,,,300,44000

If none of this works, see if you can trade the modem in on a US Robotics external - they seem to work better on impaired phone lines. My line is so bad that I can't get a winmodem or a Rockwell working faster than 28800, but my USR is running well at 37333 with no string modifiers and downloads at 4+ KB/s.

[{anonymous}]

ok, im in college right now, i will try when i get home and will post results. thanks glc

mike

[AlwaysUp]

GLC, that new USR 2976 that's on my wife's machine is connecting at 25....something, but really slow. My SupraExpress i56 V.90 ISA modem connects at 31,200bps, same phone line. Would the above strings work for me too?

[glc]

Nope - because USR uses a different command set, and you are not connecting at V.90 with either modem due to your phone line or ISP. Compare your throughputs - USR's have a tendency to connect low and train up where Conexants connect high and train down - you may be getting the same throughput. Indicated connect speed isn't really that important. You also may have a slight incompatibility between USR and your ISP's equipment, if that's the case you will have to get an external Conexant for her machine to squeeze the last bit out of it. There really isn't a way to tweak a USR that's connecting at V.34 speeds, just X2/V.90.

I feel your pain - I'm imprisoned in a 36 to 40k dialup myself.

Edit: Conexant = Rockwell

[Tuf]

"I feel your pain - I'm imprisoned in a 36 to 40k dialup myself."
No broadband in your area? I can feel your pain...lol. I spent most of the last couple of years in Hotels where usually you are lucky to get 24.4. You can take a shower and eat dinner while your email downloads.

[glc]

No broadband - SBC/Ameritech won't turn on the Project Pronto DSL extender boxes in IL and I'm 24000 feet from the switch. My local cable company is now AT&T, but they inherited an old infrastructure in their buyout, and considering they just signed a 15 year contract with the city they have no incentive to upgrade it to internet-capable. I refuse to pay the going price for ISDN or IDSL and I've played with satellite systems, they aren't worth it either. If I really need something big I have enough customers and friends with broadband and cd burners, otherwise I queue up downloads for when I sleep.

[AlwaysUp]

I presently pay 19.95/mo for my dialup account. Cable modem is available for 39.95/mo. Just haven't wanted to double my monthly bill as yet.

[{anonymous}]

glc - i tried the string u provided and it did work, imnow connecting @ 44,000bps - and my download speeds are 3.5 kb/s - 4.5kb/s - hope it stays like this, thanks for everyone's help

mike

[glc]

Now try 42667 and see if it's even better - find the sweet spot. That's still a bit low for 44k.

[{anonymous}]

ive changed it to 42,667 now and they r way up to 5-6.5kb/s :) thanks for everyones help.

mike