I’ve search for this problem on numerous forums but haven’t been able to find a helpful answer.
I have a system with
1GB RAM, more than enough CPU
Openvox A400P with 2 PSTN lines connected
7 st2030 phones, in the same 100Mbps LAN.
I have a problem I can’t get rid of: Sometimes, when a call is received, after a while in the conversation, the sounds produced in the IP phone side are kind of encoded into DTMF beeps. The first time this happened to me, I thought someone was dialling on the same line, but I realized that the tones weren’t always the same and, they were produced when a sound in the IP phone side was produced.
Needless to say this makes the conversation impossible.
This happens with any PSTN Analog VoIP device. Make sure you got the latest firmware. Report the problem to your hardware vendor. Sometimes people’s voices hit the right DTMF frequencies to trigger the DTMF tones. This is unavoidable with analog devices. With a digital line/device (T1 or ISDN), it is non-existant.