U 193.126.48.33:5060 -> 200.193.194.142:5060
  REGISTER sip:sip.televoip.net SIP/2.0..Via: SIP/2.0/UDP 192.168.0.111;branch=z9hG4bK4977acbbc428883a..From: "Reginaldo Paula Souza" <sip:reginaldo_ptt@sip.televoip.net>;tag=307110492b802983..To: <sip:reginaldo_ptt@sip.televoip.net>..Contact: *..Call-ID: 6221319848b4afe5@192.168.0.111..CSeq: 106 REGISTER..Expires: 0..User-Agent: Grandstream HT286 1.0.4.68..Max-Forwards: 70..Allow: INVITE,ACK,CANCEL,BYE,NOTIFY,REFER,OPTIONS,INFO,SUBSCRIBE..Content-Length: 0....
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U 200.193.194.142:5060 -> 193.126.48.33:5060
  SIP/2.0 401 Unauthorized..Via: SIP/2.0/UDP 192.168.0.111;branch=z9hG4bK4977acbbc428883a;rport=5060;received=193.126.48.33..From: "Reginaldo Paula Souza" <sip:reginaldo_ptt@sip.televoip.net>;tag=307110492b802983..To: <sip:reginaldo_ptt@sip.televoip.net>;tag=a791a9ab0b94eb4c05eab9b15c0fec4f.f9b6..Call-ID: 6221319848b4afe5@192.168.0.111..CSeq: 106 REGISTER..P-NATed-Caller: Yes..WWW-Authenticate: Digest realm="sip.televoip.net", nonce="40d46cd7c8d155389bef79bb516a0a2b2a5524f8"..Server: Sip EXpress router (0.8.13-dev-30-db_api (i386/linux))..Content-Length: 0..Warning: 392 200.193.194.142:5060 "Noisy feedback tells:  pid=11293 req_src_ip=193.126.48.33 req_src_port=5060 in_uri=sip:sip.televoip.net out_uri=sip:sip.televoip.net via_cnt==1"....