the issue is quiet sure codec based: [Oct 24 15:32:41] NOTICE[3731]: channel.c:4280 __ast_read: Dropping incompatible voice frame on SIP/messagenet-0000028e of format gsm since our native format has changed to 0x8 (alaw) shorter: Dropping incompatible voice frame on SIP/messagenet-0000028e of format gsm since our native format has changed to 0x8 (alaw) looks like your android phone uses gsm, but only alaw is supported. just try to put gsm as allowed codec. the sip invite and ok-message would be interesting as well (especially sdp)- regards, andre