Showing the caller id on Call Conference on asterisk 1.4

Hi,
Here is my problem below :
Im using Asterisk 1.4 Contaque Dialer.
The call is made from server to customer and connected to agents waiting for calls. The agents conferences the call to third party. The 3rd party sees the Caller ID of agent.

Now, what I want is to display the caller id or the phone number of the customer to the 3rd party.

Example:

Agent calls the Customer’s phone ex XXXXX and call is received. Agent puts Customer on hold and dials Mr CLIENT, another phone number ex YYYYY. The conference call is made(customer, agent and Mr. CLIENT are in conference). I want Mr. CLIENT to see the Customers Number asap the Customer is Connected to the conference.
Please Guide me.What to modify to sip.conf and extensions.conf to achieve the goal.or what else extra do i need to do?
Tons of Thanks.

It is not entirely clear what you are doing as a lot of this may actually be being done by the phone, not Asterisk, but Asterisk 1.4 is obsolete and doesn’t support connected line presentation updates. You will need to present the other party’s number on the initial setup, which means that Asterisk will need to know that the call is related. The only way I know of doing this is with third party control. It will never work with SIP transfers. I don’t know if any variables are set during features transfers that would support this.