Missed call list not dialing out to the user in VVX 500

Hello,

          We have one issue regarding polycom VVX 500.below is the detailed description of the issue.

1) We have shared lines on two polycom vvx phones,these phones are part of the same BLA Group. 

2) When the call came to the BLA group,the two phones starts to ring then we lift the call at         one polycom phone and end the call.on the other polycom phone that call is in  missed call list.

3) When i try to dial out from the missed call list...phone showing "URL dialing disabled" ...

How we  can solve this issue..I have tried with feature.urlDialing.enabled=1,its working but for every call it showing ip address.

you guys have a better solution for this?

Below is the Required info of the Phone (For VVX 500):

Phone Model : VVX 500
Part Number : 3111-44500-001
Rev : A
MAC Address : 00:04:F2:D1:58:25
IP Mode : IPv4
UC Software Version : 5.8.1.6389
Updater Version : 5.9.6.6357
Camera Software Version : 1.0.0

Call Server : Opensips

Thanks