Hi all, My network is like this: ---------------------------- | | | | | Private network | ----------- NAT----------Internet ----------------- SER server | | | | ---------------------------- And I use SER+mysql DB. For a SIP terminal there are only one number and for a number there are only one SIP terminal. For a call I need to know only one URI. So that I set : modparam("registrar", "append_branches", 0) That mean I must get the last register infomation for a SIP terminal because of NAT port maybe change when SIP terninal reboot(Maby power off and power on so that maybe no unregister packets sent). So that I set: modparam("registrar", "desc_time_order", 1) to get the most current URI. I don't know what mean with the parm default_q, sometimes I set it as 50, sometimes use default value 0. But SER often call to the URI wrong. Looking my recorder: I use a SIP terminal named 1001. The terminal register multi times. So I can get many I get usrloc information by command "serctl ul show" like this: ===Domain list=== ---Domain--- name : 'location' size : 512 table: 0x402e7998 d_ll { n : 2 first: 0x402e99a0 last : 0x402e9a80 } ...Record(0x402e99a0)... domain: 'location' aor : '1001' ~~~Contact(0x402e9b48)~~~ domain : 'location' aor : '1001' Contact: 'sip:1001@218.107.145.102:7035' Expires: 131 q : 0.00 Call-ID: '3BAFC06D5BD54939A3114CABF35D1FE0(a)novsky.com' CSeq : 11838 replic : 0 State : CS_SYNC Flags : 1 next : 0x402e9be8 prev : (nil) ~~~/Contact~~~~ ~~~Contact(0x402e9be8)~~~ domain : 'location' aor : '1001' Contact: 'sip:1001@218.107.145.102:7011' Expires: 36 q : 0.00 Call-ID: 'D125943999FF4907BCD175EEFE3DE24A(a)novsky.com' CSeq : 43236 replic : 0 State : CS_SYNC Flags : 1 next : 0x402e99e0 prev : 0x402e9b48 ~~~/Contact~~~~ ~~~Contact(0x402e99e0)~~~ domain : 'location' aor : '1001' Contact: 'sip:1001@218.107.145.102:7080' Expires: 1794 q : 0.00 Call-ID: '9658F25C5E3040C1AE4C3405032B7558(a)novsky.com' CSeq : 63264 replic : 0 State : CS_NEW Flags : 1 next : (nil) prev : 0x402e9be8 ~~~/Contact~~~~ .../Record... ...Record(0x402e9a80)... domain: 'location' aor : '1000' ~~~Contact(0x402e9ac0)~~~ domain : 'location' aor : '1000' Contact: 'sip:1000@218.201.88.163:1083' Expires: 2565 q : 0.00 Call-ID: '3350078894(a)172.16.3.80' CSeq : 4 replic : 0 State : CS_SYNC Flags : 1 next : (nil) prev : (nil) ~~~/Contact~~~~ .../Record... In the list we can find that last register use NAT port 7080 by check expires time. I use this terminal -- 1001 to call 1001, It should return 486 BUSY in normal. But it didn't reponse. See that packet I get by tethereal: 291.677702 218.107.145.102 -> 218.201.88.164 SIP/SDP Request: INVITE sip:1001@novsky.com, with session description 291.702534 218.201.88.164 -> 218.107.145.102 SIP Status: 407 Proxy Authentication Required 291.822811 218.107.145.102 -> 218.201.88.164 SIP Request: ACK sip:1001@novsky.com 291.824597 218.107.145.102 -> 218.201.88.164 SIP/SDP Request: INVITE sip:1001@novsky.com, with session description 291.868197 218.201.88.164 -> 218.107.145.102 SIP Status: 100 trying -- your call is important to us 291.870300 218.201.88.164 -> 218.107.145.102 SIP/SDP Request: INVITE sip:1001@218.107.145.102:7035, with session description 292.045669 218.201.88.164 -> 218.107.145.102 SIP/SDP Request: INVITE sip:1001@218.107.145.102:7035, with session description 294.065633 218.201.88.164 -> 218.107.145.102 SIP/SDP Request: INVITE sip:1001@218.107.145.102:7035, with session description 298.105648 218.201.88.164 -> 218.107.145.102 SIP/SDP Request: INVITE sip:1001@218.107.145.102:7035, with session description I find SER get the wrong URI and send to NAT port 7035. It sometimes happens but not always. How to deal with that. Br, Wangji