How to switch from analog phone line to IP?

Question

Telephony

Good evening! the boss wants to switch to sip phones, which is given:
1) 600 subscribers in the building (600 analog phones)
2) 160 external analog numbers
The task is this:
1) raise asterisk, which in principle will be done.
2) reduce external numbers by half or maybe more.
3) Connect these numbers to asterisk.
How can I leave analog external numbers in such a quantity and will it all work fine if the number of numbers is reduced, will people be able to call from 1 number at the same time, etc.?

Answer 1

FXO/FXS cards to help you.
The first link in Google: https://www.voip-shop.ru/asterisk_cards.htm
No. Make a pool of numbers, the maximum number of simultaneous calls will be 160 pieces.
All this is configurable, it makes no sense to explain here, since there are a lot of manuals specifically on this topic.