F5 can not persistence/route the SIP messages

Hi expert

 

I need your help ！

 

recently, i have tried to use F5 to LoadBalance the sip traffic. however, some interesting issue has occurred :

 

My sipp tool sent SIP:INVITE message to F5's VIP+port, and F5 forward this message to my sip server ,then my sip server response the SIP:100trying message back to F5 ,the problem is F5 didn't forward this message to sipp tool,and report the error: : port unreachable

 

I have already added the sip_persistence configuration on F5 ,using Call-ID to persis the session keeps alive .

 

 

sip-persistence configuration:

 

 

sip-recource configuration: