How secure is a SIP Trunk? SIP (Session Initiation Protocol) uses virtual phone lines that enable users to make and receive phone calls over the internet to anyone in the world with a phone number. Telecom Metric recommends choosing a strong partner that will help walk you through the implementation process and support you as the needs of your business change over time. TM uses the SRTP protocol to provide media encryption and message authentication for both the phones network as well as trunking. This protects our clients from replay (man-in-the-middle) and eavesdropping attacks. If you have additional questions about how SIP might work for you, we’re happy to help. Learn More: SIP Trunking Secure Voice Communications What Is SIP Trunking?