I use android client CSipSimple. This software has the feature of sending SIP text message. I also use a GOIP PSTN gateway device. This device has the feature of transforming a GSM SMS to a SIP text. So theoretically, CSipSimple should be able to talk with my GOIP and when people send SMS to my PSTN device I should be able to receive it on my SIP software phone CSipSimple; The problem is, when both GOIP device & CSipSimple are registered to 3CX, the SIP INVITE with MESSAGE method just not passed-by by 3CX server; Does anybody know how 3CX phone system handle SIP INVITE with MESSAGE method? blocked it? or just discard it?