How to convert analog telephony to digital?

Question

Telephony

Good afternoon!

Help me understand friends! There is an office, 2 analog telephone lines, 15 PCs, 15 headsets, a local area network, a server.
Initially, I wanted my provider to throw me a "SIP cable" and I would calmly set up a "dialer" on all PCs on the network via asterisk, but in this case I would have to sacrifice numbers. Since I really don’t want to lose numbers, the question arose: How and with what equipment to convert analog telephony to digital? In general, I guess that a mini-ATS will help me with this, but I can’t figure out which one (analogue, digital) in any way.

ps I apologize in advance for the crooked terminology :-)

Answer 1

fxs/fxo gateways, depending on where to convert.