Cannot get caller id via digium card

I’m using AsteriskNOW. Today I got a digium card. It’s easy to attach it and get it worked. But, after making some test calls, I checked CDR list and found a problem: all Caller IDs were set to ‘Unknown’. It looks very strange because I also have a SIP trunk (Skype) and it shows Caller ID very well.
I need to know Caller ID. Please help me!

You need to set up dahdi to agree with the callerid you get from your provider, that will be very provider specific.

Thanks for your reply.
Sorry about my limited knowledge, but what do you mean in ‘your provider’? You mean telephone company? And some parameters for example ‘callerid’, ‘cidsignalling’ and ‘cidstart’ in terms of ‘set up dahdi’?

Yes your provider is your phone company, No examples can be given because it depends on how the phone company sends you the callerID there are several different methods.

You are right. I checked my PBX with another analog phone line, it worked well. I then called to the telephone company and ask them to send callerID to my server, and everything is okay now.
Thanks!!!