"NO CARRIER" error in V.90 modem.. help~~

[whoami2000au]

I have Aztech 56k V.90 USB external modem.
In about 7 out of ten times, the modem disconnects itself 1-2 minute after it's connected. And even when it's connected (usually at 50-54K rate), sometimes I have to try clicking a hyperlink several times (and wait) to get the response from the web server I'm trying to reach. I'm assuming there are lots of error involved with the connetion. I'm not sure how much throughput I'm getting at.
Well.. so I logged the modem activity and found that there is "no carrier" error whenever the modem disconnects itself. (I don't know what it means)
What shall I do not to get this "no carrier" error...??
Please help me.. I'm in great distress now

 

[whoami2000au]

pretty please?

 

[Fardringle]

If your modem is constantly losing the carrier, it is usually because you are getting too much line noise and it drops the connection, or because the modem is configured incorrectly, or your ISP is dropping the connection, or the modem is going bad. If you can post the section of your modem log where the connection is being lost, we can probably help pinpoint the problem...

 

[whoami2000au]

Hmm..what's carrier and why am I losing it?
If it's line noise.. anything I can do about it?
The wait time for carrier is set to 60 seconds. I think that's why I lose the connection in about a minute..
Can I just increase the time and decrease the connection speed for the better reliability? Should I use MNP instead of RLSD for error control?

Ah.. the log ..My windows98 is korean version so.. the log text is written in korean..
I'll try to translate here..Here it goes

02-22-2001 10:17:39.37 - UM9800 V.90 USB Modem is being used.
02-22-2001 10:17:39.37 - modem: UM9800 V.90 USB Modem
02-22-2001 10:17:39.37 - inf path: MDMSLUSB.INF
02-22-2001 10:17:39.37 - Inf section: Modem1
02-22-2001 10:17:39.45 - 460800,N,8,1
02-22-2001 10:17:39.45 - 38400,N,8,1
02-22-2001 10:17:39.45 - modem is being initialised.
02-22-2001 10:17:39.45 - sent: AT<cr>
02-22-2001 10:17:39.45 - received: AT<cr>
02-22-2001 10:17:39.45 - received: <cr><lf>OK<cr><lf>
02-22-2001 10:17:39.45 - respons explanation: confirmed
02-22-2001 10:17:39.45 - sent: AT &amp;F E0 V1 &amp;A3 &amp;D2 &amp;C1 S0=0<cr>
02-22-2001 10:17:39.45 - received: AT &amp;F E0 V1 &amp;A3 &amp;D2 &amp;C1 S0=0<cr>
02-22-2001 10:17:39.45 - received: <cr><lf>OK<cr><lf>
02-22-2001 10:17:39.45 - respons explanation: confirmed
02-22-2001 10:17:39.45 - sent: ATS7=60S19=0L1M1\N3%C3&amp;H1N0X4<cr>
02-22-2001 10:17:39.45 - received: <cr><lf>OK<cr><lf>
02-22-2001 10:17:39.45 - respons explanation: confirmed
02-22-2001 10:17:39.47 - dialling.
02-22-2001 10:17:39.47 - sent: ATDT;<cr>
02-22-2001 10:17:43.01 - received: <cr><lf>OK<cr><lf>
02-22-2001 10:17:43.01 - respons explanation: confirmed
02-22-2001 10:17:43.01 - dialling.
02-22-2001 10:17:43.01 - sent: ATDT########<cr>
02-22-2001 10:18:11.17 - received: <cr><lf>MODULATION: V.90
02-22-2001 10:18:11.17 - respons explanation: information
02-22-2001 10:18:11.17 - received: <cr><lf>PROTOCOL: LAPM
02-22-2001 10:18:11.17 - respons explanation: information
02-22-2001 10:18:11.17 - received: <cr><lf>COMPRESSION: V.42BIS
02-22-2001 10:18:11.17 - respons explanation: information
02-22-2001 10:18:11.17 - received: <cr><lf>CONNECT 50666<cr><lf>
02-22-2001 10:18:11.17 - respons explanation: connection
02-22-2001 10:18:11.17 - It's connected at 50666bps.
02-22-2001 10:18:11.17 - Use error control.
02-22-2001 10:18:11.17 - Use data compression.
02-22-2001 10:19:25.58 - Disconnecting remote modem.
02-22-2001 10:19:25.58 - received: <cr><lf>NO CARRIER<cr><lf>
02-22-2001 10:19:25.58 - respons explanation: There is no receiver
02-22-2001 10:19:25.69 - Trying to disconnect the modem connection.
02-22-2001 10:19:25.69 - sent: ATH<cr>
02-22-2001 10:19:25.69 - received: <cr><lf>OK<cr><lf>
02-22-2001 10:19:25.69 - resons explanation: confirmed
02-22-2001 10:19:25.69 - 38400,N,8,1
02-22-2001 10:19:26.74 - session statistics:
02-22-2001 10:19:26.74 - read : 455 byte
02-22-2001 10:19:26.74 - write: 2651 byte
02-22-2001 10:19:26.74 - UM9800 V.90 USB Modem is disconnected.

Any insights??
Is it something to do with carrier?
I don't know what a carrier is or what it does.. can somebody tell me what it is?

I upgraded the driver to the latest one, and I believe the firmware is not flashable..so.. I don't think I can upgrade that one. Maybe I'm wrong.
I'll write down what the AT command above means..
E0 - Disable command echo of characters to DTE
(what does it mean?)
M1 - Speaker on from the start of dialling until receiving carrier
N0 - Automode detection disabled (enabling it doesn't seem to make difference)
V1 - verbose result code
X4 - all extended result code
L1 - low speaker volume
&amp;A3 - connect message format
&amp;C1- RLSD floows the carrier state (control carrier state)
&amp;D2 - DTR follows DTR circuit definition
&amp;F - select factory setting 0
&amp;H1 - hardware flow control RTS/CTS emulation
\N3 - Attempt LAPM first then MNP then fall back to normal (no error control)
%C3 - Enable MNP 5/V.42bis data compression
s19=0 - system inactivity timer =0
s7=60 - wait time for carrier is 60 seconds

I don't know what these all means ..but I'd like to try some extra init string..
First, I'd like to limit the maximum speed of connection.. or disable the 56K
But I can't do that because their official ATcommset is so out of data that there is no mention of V.90 module and the supported speed!
I can try to increase the S7 (wait time for carrier) or fiddle with S9(carrier detect response time) or S10 (carrier loss disconnect time)..
I'm not too sure what each one does though..
I can also force the modem to use MNP for error control..
There is this AT command that does the line quality control(%En) which can automatically retrain or forward/fall back depends on the quality.
I don't know...
Please somebody suggest me what I should do...


and also... I'm not familier with many terms with modem.. can somebody clarify what these are and what they do please?

1. RTS CTS DTS..
2. command echo
3. RLSD
4. Retrain

Any help greatly appreciated..
Thanks for reading such a long post

 

[breweyez]

http://808hi.com/56k/index.htm
Try the link above. There will be a few directions to go in. First I would try the init string link. You may want a string that would slow down the handshake . It may stablize the conection and reach the max potential of the phone line. I ran into a similar problem with my phone line.

 

[whoami2000au]

can't find the init string for slowing down the handshake..

 

[whoami2000au]

and what the hack is PBX? My modem has it enabled...

I need this modem fixed..
This girl I like use this modem a lot..and I can be a hero by fixing ot for her!!

 

[blargyblarg]

another link:
www.modemhelp.net

 

[esung]

hmm.. try disable PBX support.. never seen one in a modem though.
PBX stands for private branch exchange, basically your office phone exchange system...

 

[whoami2000au]

Does anyone know how I can slow down the handshake process??
I'll try disabling PBX today
(by the way, the computer is not at home.. so it takes time to troubleshoot)

 

[DaddyG]

Here's some help with the terminology. RTS is Request to Send, this signal is set by the Data Terminal Equipment (in your case your Dialer). CTS is Clear to Send, this signal comes from the modem when its OK to send data. DTS, could this be DTR, Data Terminal Ready, also a signal from the DTE, the modem will not answer a call without this signal. DSR or MR is data set ready, thats the modem, this signal usually only comes on when the handshake sequence is complete.

Modem retrain is a term used to re-establish the connection when errors occur. Each modem sends a very specific signal to the other, Based on the actual signal recieved, each modem makes 'corrections' to its circuitry. They will also 'negotiate' a specific connection speed, and the features that they support.

BTW, the carrier is the basic signal that exists between the modems. When data is present, the carrier is modulated both by amplitude and frequency. Loss of carrier means that your ISP modem hung up, or the signal was so bad, that your modem could not find it.

 

[aaronbrager]

Hey I'm having the same problem did you guys ever get it working?

Which protocol are you using, V.90, K56flex, or X2?

I'm running iOS 9, Beta 5 if that matters.

 

[Ken g6]

Wow, you're using a telephone modem in this day and age?

I remember having a problem like this in college. I was behind a PBX and had to find commands to drop my modem to 28.8. (No, I don't remember what they were.)

 

[shabby]

Hey I'm having the same problem did you guys ever get it working?

Which protocol are you using, V.90, K56flex, or X2?

I'm running iOS 9, Beta 5 if that matters.

Those modem's are plug and play, just plug them in and they should play...

 

[splat_ed]

1) Isn't iOS 9 for the iPhone? Why are you trying to use a modem with a smartphone?

2) And this thread is 14 years old!

 

[bononos]

1) Isn't iOS 9 for the iPhone? Why are you trying to use a modem with a smartphone?

2) And this thread is 14 years old!

Its his first post and the faq/welcome notice might not have warnings against necroing old threads. Really should have some system of moderated posts for new posters or date checks.