Dear ALL: My scenario lists below: Assume: UA1 with sip id "1011" And dial number to PSTN is "0939749xxx" There is no modification rule at my CISCO. (It will not change any dialed number) UA1 ==> SER ==> UA2 (SIP to SIP) UA1 ==> SER ==> Asterisk ==> CISCO 5300 ==> PSTN (SIP to PSTN) port:5060 port:5065 port:5060 IP:xxx.xxx.190.248 IP:xxx.xxx.190.243 (On the same server) (On another server) I know how to forward a call from ser to CISCO 5300. And I have done it ever. UA1 ==> SER ==> CISCO 5300 ==> PSTN Now I modify the ser.cfg, and want to forward all calls to PSTN to the port 5065 of Asterisk on the same server. And Asterisk should accept the call and forward it to PSTN via CISCO 5300. 1. UA1's SER SIP id is "1011" (Assume all SIP account is 4 digists and first leader number is not zero) 2. UA1 want to dial my mobile phone number 0939749xxx 3. CISCO will forward this call to PSTN, I only modify extensions.conf & sip.conf. I can make a call from UA1 to 0939749xxx via SER and Asterisk to CISCO. But I can not hear any voice in UA1 or my mobile phone. What's wrong in my setting? Does Anybody help me? Thank you for your kind to read and answer my question. PS: How can I set the maxinum log level to /var/log/asterisk/messages ? I start my asterisk with the sample of redhat and "/etc/init.d/asterisk restart". Best Regard Charles In my extensions.conf: ------------------------------------------------------------------------------------------------------- [general] static=yes writeprotect=no [globals] SERADDRESS=xxx.xxx.190.248:5060 CISCOADDRESS=xxx.xxx.190.243:5060 [ser] exten => _XXXXXXXXXX,1,Dial(SIP/${EXTEN}@${CISCOADDRESS},60) [cisco5300] exten => 1055,1,Dial(SIP/${EXTEN}@${CISCOADDRESS},60) In my sip.conf: ------------------------------------------------------------------------------------------------------- [general] context=ser port=5065 bindaddr=0.0.0.0 register => 1055:1055@ser.xxx.net.tw ; using to register to SER SIP server [cisco5300_pstn] type=friend defaultip=xxx.xxx.190.243 amaflags=default ; Choices are default, omit, billing, documentation disallow=all allow=ulaw allow=alaw allow=g729 allow=g723.1