Tag Archives: RTP

Fax & Voip – Part 2/3 – From Vad to Clock……

Codec Translation I have already mentioned before. In the path caller->called codecs can change several times, and every transformation can introduce distortion and delay. To minimize fax issues all the legs involved must be using the same codec to avoid … Continue reading

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Fax & Voip – Part 1/3 – All about codec in Fax transmission

Certainly there are huge benefits in adopting VoIP technology (i.e. Asterisk PBX), and certainly there will be many people who will be wise to use Voip PBX trunk instead of traditional phone lines. But using Voip PBX you may start … Continue reading

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Strange issue with Sonicwall TZ 100/Asterisk 1.8 and a famous VOIP ISP

I want to tell a very strange issue occoured some weeks ago using pbx Asterisk 1.8, an router/firewall Sonicwall TZ 100 and a famous Voip ISP. The system has always worked fine until a couple of weeks ago (pls see … Continue reading

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From SIP to RTP (Part 6) – The phone is ringing….

Real Case: Asterisk receive an external call A call from an external number to our pbx using a SIP trunk. Att: I have “sniffed” that traffic using tcpdump. In the next the Asterisk pbx is inside a LAN network, and … Continue reading

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