GSM gateway

GSM-gate is designed for mobile subscribers switching. The external device communication channels are Internet and GSM. This device has distributed architecture. As part of the allocated base module with 32 GSM modems and GSM module connected through the Internet with the 128th SIM-cards.
Implemented and adapted:
  • SIP server for the organization of VoIP telephony, interfacing with external devices such as Soft Switch and organization of incoming calls;
  • Open VPN to establish connection;
  • RTP and SRTP protocols for data exchange;
  • Encoding and decoding of audio streams in the format G.729, G.711, and Opus.