i use patton sn4960 as gateway betewen astrerisk and our pstn network with r2 signaling. the problem is i dont get ringing signal from the patton to asterisk. asterisk play message but the called person does not answer his phone ring.
Please be more specific about the setup and give more details. What firmware version are you using on the Patton? Can you give some details about the Patton config and the Asterisk SIP peer config? Did you try debugging this problem on the Patton? The gateway has excellent debugs.
I am mostly using Patton BRI gateways for connecting ISDN BRI lines to Asterisk and I naver had any problems. Configuring a PRI gateway is not too different from configuring a PRI gateway, so I think that I can help out. Patton is a very good gateway and Asterisk is a very good IP PBX, so the setup should work with no problem 
problem fixed
i have active in interface sip early-connect parameter.