Hi, I would like to try use the module nathelper with rtpproxy to test when INVITE , voice (rtp) can pass nat and firewall, just like (http://www.informatik.uni-bremen.de/~prelle/terena/cookbook/main/ch04s07.ht… 4.7.3.5.1. SIP Express Router mentioned), but ser crashes after receive REGISTER but after REGISTER , ser crashe... ================================================================= syslog: BUG: 15 (23183) tcp_main_loop: dead child 5 0 (23168) child process 23173 existed by a signal 11 0 (23168) core was not generated 0 (23168) INFO:terminating due to SIGCHILD ... ... ================================================================= i install ser0.8.12 , and download newest nathelper , rtpproxy form berlios cvs Makefile rev 1.6 nathelper.c rev 1.51 nathelper.cfg rev 1.2 nathelper_rtpp.cfg rev 1.1 nhelpr_funcs.c rev 1.7 nhelpr_funcs.h rev 1.2 rtpproxy main.c rev 1.17 ... ... My environment is kphone 3.14 -------> Gateway(NAT+Firewall) ----Internet----Ser + rtpproxy kphone use UDP , Symmetric Signaling and Symmetric Media , not use STUN server my ser.cfg is the same as the link (http://www.informatik.uni-bremen.de/~prelle/terena/cookbook/main/ch04s07.ht… 4.7.3.5.1. SIP Express Router mentioned) besides one line if (method == "REGISTER" || ! search("^Record-Route:")) { ===> ser said it is wrong , i don't what's wrong...? so i modify it to if (method == "REGISTER") { My question is : 1. Does the idea (http://www.informatik.uni-bremen.de/~prelle/terena/cookbook/main/ch04s07.ht… 4.7.3.5.1. SIP Express Router mentioned) work? 2. used ser 0.8.12 and only update nathelper module to newest work? Thanks Jimmy