Hello all, I installed ser with nathelper, the copy from CVS. It work well when i use cisco ATA or Xlite call to PSTN. ATA --> NAT --> ser + nathelper --> cisco gw (as5300) --> PSTN. But i found that call from GW to ATA have a problem. The phone in ATA is ring, but have one way voice, PSTN can hear, but Phone in ATA not. PSTN --> cisco gw (AS5300) --> ser + nathelper --> NAT --> ATA The Nathelper not work and with a error in log. "ERROR: force_rtp_proxy2: can't get From tag" I use ethereal found the cause is that call from cisco GW not haven't tag in INVITE from head. like this: =============================================== From: "87654321" <sip:87654321@222.222.222.2> To: <sip:12345678@333.333.333.3;user=phone;phone-context=local> =============================================== If call from ATA have a tag, and the nathelper can work. use ethereal get these in INVITE message. ================================================ From: <sip:12345678@333.333.333.3;user=phone>;tag=3021292464 To: <sip:87654321@333.333.333.3;user=phone> ================================================ I try to change the code in nathelper.c line 1297 "if (get_from_tag(msg, &from_tag) == -1 || from_tag.len == 0)" ==> "if (get_from_tag(msg, &from_tag) == -1)" Then the nathelper have no error, but RTP proxy have error log when i start rtpproxy with "-f" i get this: "command syntax error" So I think rtpproxy maybe need from_tag to work, if i skip this it may not work. I want to know how to make them work. How to change the config at cisco 5300, so it's INVITE with tag, or do some change both on nathelper and rtpproxy'code. My cisco 5300 IOS is 12.26(a). I also do testing with 12.27(c). Same result. Please help me out. Sorry for my poor English. -- Best regards, 　 opera 　　　　　　　　　　　　　　accmail(a)21cn.com 　　　　　　　　　　　　　　　　　2004-12-31