Hi

I've got a NS 500 at the main site and 2 sites that connects via a VPN to the main site. On the 2 sites i have a desktop IP Phones and i am using i_serve dect base station as portable phones. The i-serve connects via SIP extensions to the PABX. My problem is that the SIP extensions keeps on de-registering but the desktop phones work. In order to get the SIP extensions to work again i have to de-register them restart the pabx, re-program the SIP password and re-start the i-serve base stations. The SIP extensions will then register again and it will work for about 8 hours. This problem happens every day. The NS 500 is on the latest version firmware.