Symbio is introducing enhanced communications security with support for TLS (Transport Layer Security) and SRTP (Secure Real Time Protocol).

SIP TLS: Secure calling in Asia-Pacific

Moei Akhal

Product Manager

January 24, 2024

Support more secure calling in Asia-Pacific

Today, Symbio is introducing enhanced communications security with support for TLS (Transport Layer Security) and SRTP (Secure Real Time Protocol). The enhancement means Symbio customers can now deliver more secure calling across the Asia-Pacific.

Both TLS and SRTP are optional features of our voice termination service available to domestic and international telecom providers.

SIP TLS / SRTP support is now available for customers in Australia, Singapore and Malaysia – and can be applied to both inbound and outbound traffic.


What is SIP TLS?

SIP TLS is an extra layer of security for voice communications. It is particularly useful for securing phone calls that are routed over public internet & peering connections.

Without SIP TLS, it is possible for third parties to intercept call setup information. This vulnerability may leak privileged or confidential data.

TLS uses a combination of cryptographic process and can be applied to both inbound and outbound calls, as well as SMS. It provides an extra layer of security when connecting via public internet.


How SIP TLS works

TLS is used to secure and encrypt the transmission of call setup information shared between Symbio and our customers. Information such as when calls were made, who received them, and how long they lasted.

1.      Handshake : A TLS handshake is the establishment of a secure connection between a SIP client and a server over the internet using the TLS protocol. When this is initiated, the exchange of cryptographic keys, encryption algorithms and verify digital certificates will occur.

2.      Encryption: The media to be transferred is encrypted using symmetric encryption algorithms, ensuring it can only be read by the intended recipient.

3.      Data exchange: The encrypted media is then exchanged between the SIP client and the server over the TLS connection.

4.      Decryption: The recipient receives the encrypted media and uses the shared encryption keys to read and process.


What is SRTP?

SRTP (Secure Real-Time Transport Protocol) is another extension of Real-Time Transport (RTP) that can be applied to SIP.

While TLS encrypts the signalling (information about the call) – SRTP acts to secure the actual media being transmitted (the content of a call).

Both extensions work to enhances the encryption, confidentiality and protection of audio and video traffic.


Benefits for service providers

Scale into new regions

A growing number of global communication providers prefer to deliver SIP calling via public internet, instead of using a local cross-connect.

Using public internet– secured with SIP TLS - can be a faster, more flexible solution for extending voice coverage into international markets such as Asia-Pacific.


Protect customer data

Voice carriage over public internet can be a trade-off. Without SIP TLS, any communications over public internet are vulnerable. The incorporation of SIP TLS protects against unauthorised intercept, keeping your customer’s call setup data confidential.

SIP TLS can also be used for authentication. Digital certificates are generated act as a verification of identity which reduces the risk of unauthorised processing or access.


Meet compliance requirements

Many enterprise and government organisations demand the highest levels of security, especially for communication services. Now, with support for SIP TLS, service providers can deliver a more secure calling solution for customers in the government and corporate sector.

Enable SIP TLS / SRTP today

Support more secure calling in Asia Pacific. Contact us to discuss your requirements.

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