spa112 with analog modem

[gagliano74]

hello , I have a SPA112 connected with a 56k modem. This modem must connect to another GSM modem. I can not receive data because it does not recognize the data modem . I put the prefix * 99 and disabled the echo . any idea, sorry fo my english

[Dan Lukes]

Well, native GSM modem uses 9600Bd speed (or less). So disable high speed modulation protocols like V.34 (and above) on your 56k modem. Also, limit speed to 9600Bd or less on 56k modem side.

Also note - packet lost, high jitter or even so high round trip may cause not only low quality for audio calls, but no data transfers at all.

So make sure the end-to-end connectivity (note!! - i doesn't mean just connectivity from your side to SIP operator you are using - I mean end to end connectivity, e.g. complete path from 56k modem to GSM modem) is suitable for telephony.

[AKempf]

Hi,

we're having the same Problem. We configured our Fritzbox 7390 and the Cisco SPA 112 (Firmware 1.4.1) correctly. After the configuration we tried to test it. The 56k Modem (devolo 56k MicroLink) connects to the GSM Modem. We are using the software EMH-Combi-Master 2000 and it tells us, that we are connected with 9600 baud, but we don't receive any kind of data. We tried it also with different types of baudrates, every single time the connection establishes perfectly, but no data received.

We are using the following links for configuration:

1. http://blog.conserata.com/2013/08/fax-voip-an-fritzbox/

2. http://spakonfig.de/

3. https://www.ip-phone-forum.de/threads/cisco-spa112-an-fritz-box-7590.296109/

Thank you for your help!