The main action of a SIP Gateway is to act as an interchange point between two radically different communication networks. On the one hand, it is linked to the legacy Public Switched Telephone Network (PSTN) or conventional hardware, such as analog phones and fax machines, by such interfaces as FXS or FXO or digital T1/E1 lines. On the other end, it is attached to an IP network with t... https://www.akom.in/blog/how-sip-gateway-works-architecture-benefits-use-cases