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This post will be more or less off-topic, but since the linmodems mailing list seems to have been dead for five years now, I couldn't find any forum with a better matching topic than this to ask my questions. So, sorry for that. Perhaps someone from this list will be able to help me with my questions, or at least recommend some other, more suitable forum, where I could get an answer.
I have a Bluetooth(!) 56k modem, that I recently bought from an auction site, and I managed to more or less make it work, in the sense that I can talk to it via AT commands and it responds to them. But unfortunately I am not able to make or to receive calls with it.
The ID strings of the modem are the following:
Code:
ATI0
Agere OCM V.92 Ver2.7a (Jun 14 2004) Voice Mercury DP2SH mode-ii SERIAL
OK
ATI1
0418
OK
ATI2
OK
ATI3
Agere OCM V.92 Ver2.7a (Jun 14 2004) Voice Mercury DP2SH mode-ii SERIAL
OK
ATI4
18
OK
ATI5
OCM ,0,0E
OK
ATI6
OK
ATI7
OK
ATI8
OK
ATI9
United Kingdom
(01.00HSM0A00\\MODEM\TIA0602,TIA0578\Agere OCM Serial Modem\;6B)
OK
ATI10
ERROR
ATI11
Description Status
--------------- ------------
Last Connection Failure
Initial Transmit Carrier Rate NA
Initial Receive Carrier Rate NA
Final Transmit Carrier Rate NA
Final Receive Carrier Rate NA
Protocol Negotiation Result NA
Data Compression Result NA
Estimated Noise Level NA
Receive Signal Power Level (-dBm) NA
Transmit Signal Power Level (-dBm) NA
Round Trip Delay (msec) NA
Press any key to continue; ESC to quit.
Description Status
--------------- ------------
Near Echo Level (-dBm) NA
Far Echo Level (-dBm) NA
Transmit Frame Count 0
Transmit Frame Error Count 0
Receive Frame Count 0
Receive Frame Error Count 0
Retrain by Local Modem 0
Retrain by Remote Modem 0
Rate Renegotiation by Local Modem 0
Rate Renegotiation by Remote Modem 0
Call Termination Cause 0
Robbed-Bit Signaling NA
Digital Loss (dB) NA
Remote Server ID NA
Last PCM S PTR 00
Connection Time (msec) 0
OK
I did a bit of googling and found the following thread on the linmodems mailing list from 2008, where the poster seems to have the very same problem I have:
The only difference there was that the OP's serial modem was attached to a USB-serial adapter and mine is to a bluetooth adapter, but the ID strings (and the behavior matches pretty closely.)
Unfortunately they did not manage to resolve the problem in that e-mail thread.
In my case the modem seems to be made for the UK market, while I reside in Hungary. I don't know about the OP's modem's country, or which country the OP tried to use it.
So the current behavior is the following:
Code:
(I'm starting to call the number of my land line)
RING
ATA
ERROR
RING
ATA
ERROR
RING
(I stop calling the number)
ATDTXXXXXXXXXXX (I masked out the number I called.)
ERROR
ATZ
OK
I am currently doing a project where I connect two modems through a Linksys PAP2T, so that the two can call each other (and that setup works with other modems).
(And since this modem was not working with the PAP2T, I tried to connect it up to a land line, that's what you see above.)
My questions would be the following:
Q1. Is it possible that the UK phone network and the European (Hungarian) are different in some sets of paramters, that would actually prevent a modem made for the UK market from working with the Hungarian network? (Like in the example above, unable to initiate or accept a call, but detect an incoming ring.)
Q2. Would it be possible to modify some of the configuration parameters of the Linksys PAP2T phone adapter so that it would produce the paramters expected by, and thus work with an end-user-device like the UK-based modem?
A looonnnng time since I ever used modems....how did you make the call? Is it possible the modem answers but doesn't get the expected response from the "initiator", or is it still ringing at this time (ie not answered)?
A looonnnng time since I ever used modems....how did you make the call? Is it possible the modem answers but doesn't get the expected response from the "initiator", or is it still ringing at this time (ie not answered)?
Hi,
I made the (incoming) call from my cellphone. (As for the outgoing one, I used the (AT)DT command.)
No, the situation is that in case of an incoming call, I get the RINGs all right, but when I issue (AT)A, I get an ERROR, but the call continues to RING, until I hang up on my cellphone.
Ok, thanks for clarifying. I can't imagine why issuing 'ATA' wouldn't cause the modem to answer the call manually, unless the device is actually faulty perhaps. As a matter of interest what does 'ATS0?' return? (Query current value of S0 register). Can it be coaxed into answering automatically (eg 'ATS0=3' for 3 rings)?
Ok, thanks for clarifying. I can't imagine why issuing 'ATA' wouldn't cause the modem to answer the call manually, unless the device is actually faulty perhaps. As a matter of interest what does 'ATS0?' return? (Query current value of S0 register). Can it be coaxed into answering automatically (eg 'ATS0=3' for 3 rings)?
I tried that, but nothing seems to have happened. From my cellphone I just heard the ringing tone even after three rings... I waited till 5 rings to terminate the call:
Code:
ATS0?
000
OK
ATS0=3
OK
RING
RING
RING
RING
RING
RING
ATS0?
003
OK
Does the modem have any lights to indicate a call is coming in? I do wonder if the unit is faulty (making it deaf to the call), or if the cabling is incorrect perhaps?
Does the modem have any lights to indicate a call is coming in? I do wonder if the unit is faulty (making it deaf to the call), or if the cabling is incorrect perhaps?
No, not really. The modem looks like this: https://hup.hu/node/178264
And no, I don't think so, as the modem is outputting the RING strings on an incoming call as it should. And the cabling should be okay, as it was working okay with other devices, and the incoming call is being reported via the bluetooth serial connection.
And no, I don't think so, as the modem is outputting the RING strings on an incoming call as it should.
Yes, I thought about that just after I posted. However, clearly it can not take the line off hook for some reason. That would explain why after 'ATA' command issued, it fails to answer, and it couldn't dial out successfully. This would mean that even while dialing, you probably would still observe a dial tone if picking up a connected phone at the same time I suspect.
Yes, I thought about that just after I posted. However, clearly it can not take the line off hook for some reason. That would explain why after 'ATA' command issued, it fails to answer, and it couldn't dial out successfully. This would mean that even while dialing, you probably would still observe a dial tone if picking up a connected phone at the same time I suspect.
Unfortunately my setup is not set up in such a way that I would be able to test this.
That is why I think that this may be related to a difference between the signaling, between what the modem was made for, and what I have in the Hungarian POTS.
But then again, I have a Linksys PAP2T, which may be able to bridge that gap. If I knew what I'd need to modify in its config, then perhaps I would be able to make it work.
But I know this isn't a Telco forum, but either was, hopefully someomne will come along with time...
There isn't much in the way of signalling for a POTS line though. The ringing gets detected, and the modem should then answer. After that as long as there is modem on the other end (and a clear audio path between them) then all should be ok IMHO.
Well, things got just a bit more interesting...
I tried to use the ATH1 and ATH0 commands to try to circumvent the problems with the ATA command.
If I have the modem connected to the landline, then I can use ATH1 to pick up the phone, and I can hear something that resembles the dialtone (although pretty garbled) over the speaker of the modem.
If I call my number from my cellphone, the RINGs arrive from the modem just fine, and if I issue ATH1, then seemingly the line gets connected (as per my cellphone's display), and if I talk, then some noise (although very garbled) is being emitted from the speaker of the modem.
Code:
ATH1
OK
ATH0
OK
ATH1
OK
ATH0
OK
Now if I connect the modem to the PAP2T, the modem doesn't even RING, and if I do an ATH1, then the PAP2T doesn't even recognize it as being off the hook.
Edited to add: After I restarted the bluetooth modem, and initiate a call from the other side via the PAP2T, then the RINGs are detected fine on the modem, and when I issue ATH1, then some noise is being emitted by the modem's speaker, and the PAP2T says the call is connected, but after some time, the other side's serial modem hangs up, saying there is NO CARRIER.
Last edited by wowbaggerHU; 06-15-2022 at 03:46 AM.
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