KX-TDA50 having trouble with 800 numbers

[raist3001]

Having trouble dialing 800 numbers from a KX-TDA50. On first attempt we get a fast busy. Subsequent calls will go through. We are using a SIP trunk and the SIP trunk provider is reporting no routing issues, nor any issues in any of their captures that would cause a fast busy, then a completed call.

Is there anything on the Panasonic PBX that I should be checking?

 

[obtsystems]

have you ports forwarded on the router. are the sip trunks showing INS

 

[raist3001]

SIP trunks are active and INS. I have port fwding on the router for 5060. Why would a port forward only affect an 800 number?

 

[obtsystems]

sorry, I am in Ireland, not sure what 800 numbers are, sounds like the first attempt fails due to no connection, only way to see is run wire shark on the system using a mirror port on a switch

 

[cwc3]

ken 800,888 etc numbers = freephone