Why the answer-time=bill-time?

I find something very strange when I checked CDR, Here is one example -

““Steve” <18005551116>”,“18005551116”,“0200005123012127773456”,“default”,“SIP/18005551116-081bfcf0”,“SIP/out_cg02-08199148”,“Dial”,“SIP/00005123012127773456@out_cg02”,“2008-10-06 07:55:06”,“2008-10-06 07:55:06”,“2008-10-06 07:55:54”,“48”,“48”,“ANSWERED”,“DOCUMENTATION”,"",“1223294106.1238”,""

Why the start-time = answer-time?

Here is associated extension config -

exten => _020000.,1,NoOP(${EXTEN})
exten => _020000.,2,Answer
exten => _020000.,3,Wait(1)
exten => _020000.,4,Dial(SIP/${EXTEN:2}@out_cg02)
exten => _020000.,5,Wait(1)
exten => _020000.,6,Hangup

Is this issue related to the Asterisk version we are using now? It’s asterisk-1.2.10

Please advise, I am really appreciated.