|Time     | 10.121.1.101      | 10.121.1.252      | 10.121.1.251      |
|0.000    |         INVITE SDP ( telephone-event)          |                   |SIP From: sip:3515702677@10.121.1.252 To:sip:3515702614@10.121.1.252
|         |(1083)   ------------------>  (5060)   |                   |
|0.068    |                   |         INVITE SDP ( telephone-event)          |SIP Request
|         |                   |(9728)   ------------------>  (5060)   |
|0.441    |                   |         100 Trying|                   |SIP Status
|         |                   |(9728)   <------------------  (5060)   |
|1.278    |                   |         180 Ringing                   |SIP Status
|         |                   |(9728)   <------------------  (5060)   |
|1.281    |         180 Ringing                   |                   |SIP Status
|         |(1083)   <------------------  (5060)   |                   |
|20.862   |         408 Request Timeout           |                   |SIP Status
|         |(1083)   <------------------  (5060)   |                   |
|20.863   |                   |         CANCEL    |                   |SIP Request
|         |                   |(9728)   ------------------>  (5060)   |
|20.863   |                   |         487 Request Terminated          |SIP Status
|         |                   |(9728)   <------------------  (5060)   |
|20.863   |                   |         200 OK    |                   |SIP Status
|         |                   |(9728)   <------------------  (5060)   |
|20.869   |                   |         ACK       |                   |SIP Request
|         |                   |(9728)   ------------------>  (5060)   |
|20.967   |         ACK       |                   |                   |SIP Request
|         |(1083)   ------------------>  (5060)   |                   |