[Serusers] asterisk and ser combine, 407 proxy authentucation required !

hello! I want to realized asterisk+ser combine working,ser is working fine and asterisk working well I think,I configure sip.conf and extensions.conf voicemail.conf as the asterisk handbook ,but when I registered 2000 to dial 2001 but I get error :407 proxy authentucation required, where is problem in asterisk or ser ? blow is the log of x-lite diagnostic,Very appreciation anybody help! SEND TIME: 201758109 SEND >> 221.202.129.167:5060 INVITE sip:2001@netvoip.cn SIP/2.0 Via: SIP/2.0/UDP 10.1.16.34:5060;rport;branch=z9hG4bK1DD16D11800A4C6686A65DD7C5662FFF From: 2000 <sip:2000@netvoip.cn>;tag=3731060067 To: <sip:2001@netvoip.cn> Contact: <sip:2000@10.1.16.34:5060> Call-ID: E3160ED2-7745-4740-8E69-52E6710AF5A2(a)10.1.16.34 CSeq: 53903 INVITE Max-Forwards: 70 Content-Type: application/sdp User-Agent: X-Lite release 1103m Content-Length: 244 v=0 o=2000 201757640 201758109 IN IP4 10.1.16.34 s=X-Lite c=IN IP4 10.1.16.34 t=0 0 m=audio 8000 RTP/AVP 0 98 97 101 a=rtpmap:0 pcmu/8000 a=rtpmap:98 iLBC/8000 a=rtpmap:97 speex/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-15 RECEIVE TIME: 201758859 RECEIVE << 221.202.129.167:5060 SIP/2.0 407 Proxy Authentication Required Via: SIP/2.0/UDP 10.1.16.34:5060;rport=5339;branch=z9hG4bK1DD16D11800A4C6686A65DD7C5662FFF From: 2000 <sip:2000@netvoip.cn>;tag=3731060067 To: <sip:2001@netvoip.cn>;tag=b83deba332858fe2da009af570355a70.3a3b Call-ID: E3160ED2-7745-4740-8E69-52E6710AF5A2(a)10.1.16.34 CSeq: 53903 INVITE Proxy-Authenticate: Digest realm="netvoip.cn", nonce="42e896c750edabc9057e78d345379a4991b02378" Server: Sip EXpress router (0.10.99-dev7 (i386/linux)) Content-Length: 0 Warning: 392 221.202.129.167:5060 "Noisy feedback tells: pid=28404 req_src_ip=61.136.210.7 req_src_port=5339 in_uri=sip:2001@netvoip.cn out_uri=sip:2001@netvoip.cn via_cnt==1" SEND TIME: 201758859 SEND >> 221.202.129.167:5060 ACK sip:2001@netvoip.cn SIP/2.0 Via: SIP/2.0/UDP 10.1.16.34:5060;rport;branch=z9hG4bK1DD16D11800A4C6686A65DD7C5662FFF From: 2000 <sip:2000@netvoip.cn>;tag=3731060067 To: <sip:2001@netvoip.cn>;tag=b83deba332858fe2da009af570355a70.3a3b Contact: <sip:2000@10.1.16.34:5060> Call-ID: E3160ED2-7745-4740-8E69-52E6710AF5A2(a)10.1.16.34 CSeq: 53903 ACK Max-Forwards: 70 Content-Length: 0 SEND TIME: 201758906 SEND >> 221.202.129.167:5060 INVITE sip:2001@netvoip.cn SIP/2.0 Via: SIP/2.0/UDP 10.1.16.34:5060;rport;branch=z9hG4bK20B4A3F981D6492C9CA601C9D241F095 From: 2000 <sip:2000@netvoip.cn>;tag=3731060067 To: <sip:2001@netvoip.cn> Contact: <sip:2000@10.1.16.34:5060> Call-ID: E3160ED2-7745-4740-8E69-52E6710AF5A2(a)10.1.16.34 CSeq: 53904 INVITE Proxy-Authorization: Digest username="2000",realm="netvoip.cn",nonce="42e896c750edabc9057e78d345379a4991b02378",response="337cb9deeceb1bf01e9768b6a5452568",uri="sip:2001@netvoip.cn" Max-Forwards: 70 Content-Type: application/sdp User-Agent: X-Lite release 1103m Content-Length: 244 v=0 o=2000 201757640 201758109 IN IP4 10.1.16.34 s=X-Lite c=IN IP4 10.1.16.34 t=0 0 m=audio 8000 RTP/AVP 0 98 97 101 a=rtpmap:0 pcmu/8000 a=rtpmap:98 iLBC/8000 a=rtpmap:97 speex/8000 a=rtpmap:101 telephone-event/8000 a=fmtp:101 0-15 RECEIVE TIME: 201759640 RECEIVE << 221.202.129.167:5060 SIP/2.0 100 trying -- your call is important to us Via: SIP/2.0/UDP 10.1.16.34:5060;rport=5339;branch=z9hG4bK20B4A3F981D6492C9CA601C9D241F095 From: 2000 <sip:2000@netvoip.cn>;tag=3731060067 To: <sip:2001@netvoip.cn> Call-ID: E3160ED2-7745-4740-8E69-52E6710AF5A2(a)10.1.16.34 CSeq: 53904 INVITE Server: Sip EXpress router (0.10.99-dev7 (i386/linux)) Content-Length: 0 Warning: 392 221.202.129.167:5060 "Noisy feedback tells: pid=28398 req_src_ip=61.136.210.7 req_src_port=5339 in_uri=sip:2001@netvoip.cn out_uri=sip:2001@221.202.129.167:5061 via_cnt==1" RECEIVE TIME: 201759671 RECEIVE << 221.202.129.167:5060 SIP/2.0 407 Proxy Authentication Required Via: SIP/2.0/UDP 10.1.16.34:5060;branch=z9hG4bK20B4A3F981D6492C9CA601C9D241F095 From: 2000 <sip:2000@netvoip.cn>;tag=3731060067 To: <sip:2001@netvoip.cn>;tag=as6e0c8cea Call-ID: E3160ED2-7745-4740-8E69-52E6710AF5A2(a)10.1.16.34 CSeq: 53904 INVITE User-Agent: Asterisk PBX Allow: INVITE, ACK, CANCEL, OPTIONS, BYE, REFER Contact: <sip:2001@221.202.129.167:5061> Proxy-Authenticate: Digest realm="asterisk", nonce="43fb4632" Content-Length: 0 SEND TIME: 201759671 SEND >> 221.202.129.167:5060 ACK sip:2001@netvoip.cn SIP/2.0 Via: SIP/2.0/UDP 10.1.16.34:5060;rport;branch=z9hG4bK20B4A3F981D6492C9CA601C9D241F095 From: 2000 <sip:2000@netvoip.cn>;tag=3731060067 To: <sip:2001@netvoip.cn>;tag=as6e0c8cea Contact: <sip:2000@10.1.16.34:5060> Call-ID: E3160ED2-7745-4740-8E69-52E6710AF5A2(a)10.1.16.34 CSeq: 53904 ACK Max-Forwards: 70 Content-Length: 0