I have went through many helpful topics on the forum, but it did not resolve my problem. I am able to call extension-to-extension, receive PSTN-to-Voip calls properly. I am however unable to dial out after over a week of trying. I have followed the instructions from http: //www.3cx.com/voip-gateways/linksys-3102/ - NO LONGER AVAILABLE. Here are information regarding my setup: location: North America SPA Firmware: 5.1.7(GW) Hardware version: 1.1.5 SPA-3102: 192.168.2.2 3cx server: 192.168.2.101 PSTN virtual extension: 10008 (registered and online) ATA extension: 888 (registered and online) Error shown on 3cx: 19:51:09.441 CallConf::Rejected [CM103005] Call(2) is rejected: Not Found 19:51:09.441 StratInOut:nCancel [CM104008] Call(2): Call from Ext.101 to 16265551212 terminated; cause: 404 Not Found; from IP:192.168.2.2 19:51:09.332 CallConf:nIncoming [CM103002] Call(2): Incoming call from 101 (Ext.101) to sip:firstname.lastname@example.org Configurations: SPA Line1 http://www.krazykarz.net/images/spa-line1.pdf SPA PSTN http://www.krazykarz.net/images/spa-pstn.pdf 3CX PSTNGateway http://www.krazykarz.net/images/3cx-pstngateway.pdf 3CX Extension 888 http://www.krazykarz.net/images/3cx-Ext888.pdf I am suspecting that I setup Line1 wrong. According to the http: //www.3cx.com/voip-gateways/linksys-3102/ - NO LONGER AVAILABLE instructions, on instruction item #18+ I should be setting up an Extension for ATA(for use on SPA Line1's subscriber info), which I assume will handle the outgoing voip-to-PSTN traffice (correct me if I'm wrong!) . I created Extension 888 (configuration shown on link above) on 3cx as a regular extension. Not sure if I did that part wrong. I get the error as show earlier. If I change the subscriber information on Line1 to the authention for extension 10008 (The virtual extension for PSTN gateway on 3cx), I would get a continuous ring... but it never dialed out of course. The 3cx log would then show: 22:31:21.118 StratInOut:nHangUp [CM104007] Call(23): Call from Ext.101 to 16265551212 has been terminated by Ext.101; cause: CANCEL; from IP:192.168.2.88 22:30:53.375 CallConf:nProvisional [CM103003] Call(23): Ln:10008@PSTN-Gate is ringing 22:30:53.282 CallConf:nIncoming [CM103002] Call(23): Incoming call from 101 (Ext.101) to sip:email@example.com This simply led me to believe that it may have something to do with the subscriber info on Line1 of SPA and the extension for ATA (based on the configuation instructions) I am suppose to create on 3CX. Any ideas/help? Thanks everyone! P.