When SIPr is used as UAC and SIPp is used as UAS with the call flow “> INVITE, < 180, < 200, > ACK, <
BYE, > 200”  performance is very less. There are large number of retransmissions of 200 OK. When transaction is
set to true, these retransmissions are bit less.
Global log level is set to "ERROR".  

Below are the stats of SIPp:


                                 Messages  Retrans   Timeout   Unexpected-Msg
  ----------> INVITE             1213      0         0         0

  <---------- 180                1213      0
  <---------- 200                1213      4915      68
  ----------> ACK                1118      0         0         0
  <---------- BYE                1118      0
  ----------> 200                331       0         0         638
------------------------------ Test Terminated --------------------------------