asterisk3# ngrep -Tn 60 -Wbyline port 5060 | ./sip-dump.pl
 0.000000| 10.251.1.21:5060       > 10.252.15.24:5060
         | CSeq: 1 INVITE.        > 
         | CMD: INVITE 71         > 
         |
 0.000081| 10.251.1.21:5060       < 10.252.15.24:5060
         |                        < CSeq: 1 INVITE.
         |                        < RES: 407 Proxy Authentication Required
         |
 0.069616| 10.251.1.21:5060       > 10.252.15.24:5060
         | CSeq: 1 ACK.           > 
         | CMD: ACK 71            > 
         |
 0.123259| 10.251.1.21:5060       > 10.252.15.24:5060
         | CSeq: 2 INVITE.        > 
         | CMD: INVITE 71         > 
         |
 0.123327| 10.251.1.21:5060       < 10.252.15.24:5060
         |                        < CSeq: 2 INVITE.
         |                        < RES: 100 Trying
         |
 0.133839|                          10.252.15.24:5060      > 10.252.11.130:5060
         |                          CSeq: 102 INVITE.      > 
         |                          CMD: INVITE 9096       > 
         |
 0.135411|                          10.252.15.24:5060      < 10.252.11.130:5060
         |                                                 < CSeq: 102 INVITE.
         |                                                 < RES: 100 Trying
         |
 0.170564|                          10.252.15.24:5060      < 10.252.11.130:5060
         |                                                 < CSeq: 102 INVITE.
         |                                                 < RES: 180 Ringing
         |
 0.174867| 10.251.1.21:5060       < 10.252.15.24:5060
         |                        < CSeq: 2 INVITE.
         |                        < RES: 180 Ringing
         |
 4.798091|                          10.252.15.24:5060      < 10.252.11.130:5060
         |                                                 < CSeq: 102 INVITE.
         |                                                 < RES: 200 OK
         |
 4.799521|                          10.252.15.24:5060      > 10.252.11.130:5060
         |                          CSeq: 102 ACK.         > 
         |                          CMD: ACK 9096          > 
         |
 4.801083| 10.251.1.21:5060       < 10.252.15.24:5060
         |                        < CSeq: 2 INVITE.
         |                        < RES: 200 OK
         |
 4.904155| 10.251.1.21:5060       > 10.252.15.24:5060
         | CSeq: 2 ACK.           > 
         | CMD: ACK 71            > 
         |
10.045515|                          10.252.15.24:5060      < 10.252.11.130:5060
         |                                                 < CSeq: 101 BYE.
         |                                                 < CMD: BYE edwin
         |
10.046291|                          10.252.15.24:5060      > 10.252.11.130:5060
         |                          CSeq: 101 BYE.         > 
         |                          RES: 200 OK            > 
         |
10.048786| 10.251.1.21:5060       < 10.252.15.24:5060
         |                        < CSeq: 102 BYE.
         |                        < CMD: BYE edwin
         |