Operator assisted calls

Hi all,
Can anyone tell me how to manage operator assisted calls:
For example:
1)Custumer calls the human operator in call shop, tells the destination number.
2) Operator connects the call and leaves the customer on line with the called party.

Q: What hardware should I need for line interconnections?

P.S. I use iEnsemble gateway with iBravo billing software.

Many Thanks in advance.
Regards,
Tigran