Hi Guys. I have 3cx running on its own machine. I have a completely dedicated 100Mbps network running my voip system. no other devices at all apart from 6 AAstra 480i phones and 2 Snom m3 Dect Basestations with 4 extensions on each. It has its own dedicated ADSL line, with VoipUnlimited as the Sip Trunk. The network hardware is a basic Netgear ADSL router with QOS set for voice, and a generic 8 port 100Mbps Hub. Generally the external and internal calls are ok, but about 10 of the calls a day, internal or external are jittery from one end, generally the receiever of the call gets jittering audio, and unable to make out the call. The only response is to hang up and make the call again. This happens on all extensions. Occasionally, the other party loses all ability to hear the other end. The PBX is set to deliver audio. Are there any settings, or particular codecs that i can set to make all calls reliable and not just hit and miss. most of the other settings are straight from the factory. TIA.