I am seeing long delays before the SPA3102 goes "On Hook" when the outside caller on the my Thailand PSTN line hangs up. SPA3102 goes on hook after 30 to 60 seconds because the "Last PSTN Disconnect Reason: VoIP call ended". I have all settings as recommended in the 3CX installation guide and tones set as per http://www.3amsystems.com/wireline/tone-search.htm for Thailand. I have tried several Disconnect Tones including: 425@-30,425@-30;2(0.32/0.32/1+2) from the 3AM Systems datebase and 400@-19,400@-19;(.3/.3/1+2) from another posting in this forum. My setup is as follows: PSTN Disconnect Detection Detect CPC: yes Detect Polarity Reversal: yes Detect PSTN Long Silence: no Detect VoIP Long Silence: no PSTN Long Silence Duration: 40 VoIP Long Silence Duration: 30 PSTN Silence Threshold: medium Min CPC Duration: .150 Detect Disconnect Tone: yes Disconnect Tone: 425@-30,425@-30;2(0.32/0.32/1+2) I also have a Vonage VoIP line (PAP2) connected to another SPA3102. When a call on that line ends, the SPA3102 goes on hook quickly because "Last PSTN Disconnect Reason: CPC Signal". So this line is working fine. What should I do to detect the hang up on my Thailand TT&T PSTN line?