# Telephony ### Installing Site2Site VPN for telephony purposes To set up a VPN connection, we need you to supply: * The IP address from which you will connect to the PBX * A list of subnets on your side * On your side, you need to configure the PBX DNS (supplied by mluvii) to 10.64.0.2, to allow communication through the VPN tunnel * On your side you need to enable UDP protocol ### Network requirements In case of restrictive measures (network security at the customer's site) against the Asterisk server (90.181.255.53), the following protocols and ports must be enabled on the network (router): * UDP communication on ports 10,000-20,000 to/from asteriskmluvii.mluvii.com * TCP communication on ports 10,000-20,000 to/from asteriskmluvii.mluvii.com * TCP: 443/UDP: 443 * UDP: 5060 --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.mluvii.com/en/for-it-specialists/telephony.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.