I'm running asterisk 10.7.0 on centos 5.8 server. I've got three extensions on the LAN (two of them Linksys PAP2's) registered in asterisk that always work fine and a Linksys PAP2 extension at a remote location over the internet, also registered on asterisk. Problem is the remote extension seem to 'fall off the radar' after a few minutes and there's no audio. If I renew the registration on this PAP2/remote extension and try it straight away it works, there's ringing, two way audio, all is fine. But if I leave it and try it again after 5 minutes there's no ringing sound and no audio, just silence. It does connect because I've watched the SIP debug during the call and there is activity, plus the remote extension shows as registered in asterisk. Does anyone know the solution to this? ps: as a test I also run another soft phone at the same remote ip as the linksys pap2 and the connection on that stays fine, so the problem is with the PAP2 box. Thanks for any help.