Forwarding a telephone line over the Internet?

Question

Mobile devices

Good evening, dear visitors and residents of the resource toster.ru
There is the following scheme:
1. Office # 1 (Internet - static ip, telephone line with a number (let's say 55555))
2. Office # 2 (main) (only Internet - static ip)
Voroshil information on the Internet, which is possible through two gateways that convert the analog signal of the telephone line (if I may say so) into packets and send it over the Internet from point A to point B. There, getting into the second gateway, the signals are converted back. I have not encountered this, but it needs to be implemented. Who owns the information, tell me in detail, in detail, with the whole algorithm, and if possible, give me a tip on which equipment I should "target" (about VoIP gateways). I hope for your experience and common sense;)

Answer 1

asterisk.ru/knowledgebase/SER+how+it+work

Answer 2

In general, the scheme turned out like this: 2 VoIP gateways were
purchased (D-Link dvg-7111s and D-link dvg- 2102s
) according to the local network settings. When I pick up the handset on an analog phone, I hear a long beep (ready). Dialing any number - short beeps. In order to continue making calls, as I understand it, it is necessary to go to the city line. Now the next question: how to organize access to the city line??