3 Components of Secure VoIP Handset Communication

Security in communications should be at the top of your priority list when selecting IP telephony handsets for your business. While ensuring proper security of handsets may seem complicated and tedious, the great news is that it does not have to be either of those things – nor does it have to be expensive.

Secure VoIP handset communication can be achieved by ensuring your handsets support and are configured for SIPS, TLS and SRTP. The SIP protocols used for IP telephony were not originally designed to be secure, as SIP shares information between a client and a server. To handle this issue in IP telephony, the IETF defines SIPS and SRTP.


SIPS is an implementation of SIP over TLS to solve authentication, confidentiality, and integrity problems. The SIPS call involves passing data back and forth between the handset (client) and the voice switch (server), so if your system is set up with a known Certificate Authority (CA), the phones (clients) can verify whether or not the server’s certificate is legitimate. This avoids unauthorized devices connecting to your system.


As a successor to SSL, TLS has all the virtues of TCP but is encrypted. It is built into all mainstream browsers and email clients to enable authentication and encryption between applications and servers, where data is being sent across an insecure network.


SRTP defines its own cryptography mechanisms in RFC 3711, published in March 2004. Its goal is to ensure confidentiality, integrity, replay protection and message authentication of the packets used in IP telephony (RTP and RTCP). It does not provide availability or proof. SRTP adds a Master Key Identifier and an authentication tag to packets sent.

In today’s world of privacy concerns, you wouldn’t access your bank over an unprotected link or send credit card details in an email. You should therefore view your handset security in the same way. Why risk leaking important details and unencrypted audio over an unsecured connection? When creating your business VoIP telephony solution, place handset security at the top of your priority list and enjoy peace of mind.

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