What technology is used at call centers?

I would like to find out what technology do call centers, help lines and support centers use to receive more than 20 call at once. Am looking for a device or way to have more than five call on my telephone line into a computer based PBX to create a small phone support(hotline) for my business. All idea and answers concerning how I could create this exact or anything similar is welcome.

Thanks for viewing!

Posted in Uncategorized