Hi Guys, I'm really hoping you can help me - I'm fresh out of ideas. I have a site with 3 BT Lines (BT being the UK PSTN operator for those outside the UK) connected to a Grandstream GXW-4104 FXO gateway running the 3CX supported version of code. Most of the time, all is well, but one user is constantly having problems with calls made or received using this gateway. The problem is being reported as one party being very quiet or one side not being heard at all for several seconds. the odd thing is this issue seems to primarily affect one user only (although I'm not 100% convinced) and I have replaced that users handset twice, but no change. The problem isn't on every call but it is happening several times during the day depending on he number of calls placed or received. All IP only calls are fine. I'm now at the stage where I'm considering swapping out the Grandstream - unless anyone has any better ideas. All the phones, gateway & 3CX PC are connected to the same Netgear PoE Switch so I dont think I have LAN congestion issues - certainly no other calls are affected. I have also proven that the RTP stream is between the Phone and the gateway so there is no transcoding going on. Any suggestions no matter how stupid they sound would be great. Thanks in advance!