I use an LG pbx with 4 isdn cards installed.
My pbx support siptrung with adition of an extra card which costs a lot.
I was wandering if its possible to connect my current system with an asterix server .
I thought this might this possible by connecting the current isdn ports of my LG-PBX to an asterix machine with isdn cards installed in it ( i already have a micronet 128K TA card and a dual eicon diva isdn adapter) and use a sip trunk installed on asterix machine.
You are right - you can use ISDN PCI cards (preferably from Digium) or you can use a ISDN-VoIP gateway. In the latter case, you connect the gateway to your old PBX via BRI ports and connect the gateway to your Asterisk server via a SIP Trunk.
About the PCI-BRI cards, check out the Digium Web Site. Google is also your friend here.
If you want to check about the VoIP-BRI gateways from Patton, you can ask me I have a lot of experience with them, don’t have much experience with other similar products.