The emergence of VoLTE-capable devices is raising new security concerns for mobile network operators, as existing IMS deployments expose vulnerabilities in VoLTE handsets to other devices in the network. YateUCN unified core network brings a solution to these concerns by isolating SIP and RTP call legs between handsets.
LTE uses an IMS network to deliver VoLTE (voice services), and does so via Session Initiation Protocols (SIPs). This makes the IMS network act as a SIP proxy, performing routing, session control, and registering the UE to VoLTE. Voice is delivered through RTP from one UE to the other. Therefore, in case of a security attack, it is theoretically possible for a third party to send additional information through a forged SIP message via the IMS, to the target UE.
Voice communication in 4G LTE can also be subject to malicious acts at various layers of the channel, including at the IP packets level, the UDP, RTP, or even the codec level.
What’s more, SIP is also implemented directly in the baseband processor of the latest generation smartphones to allow subscribers to use VoLTE, making it easy to for a potential smartphone takeover to occur.
For SIP signaling, YateUCN acts as a Back-to-Back User Agent server, ensuring a secure transmission of data. B2BUA allows SIP communication from the originating party (or User Agent) to be terminated at the one side of the network, where the message is verified. Any harmful information included in the received SIP message is eliminated and the message is recomposed to include only the information needed for the SIP to reach the end party.
The risk of attacks decreases since malicious data is not automatically allowed to pass from one UE to the other, and the split SIP messages are negotiated independently on the originating and terminating sides.
Unlike current IMS deployments, YateUCN allows the same message decoding, verification, and re-encoding of RTP by acting as a proxy. This also simplifies the deployment of Voice over LTE, since handsets only need to connect to YateUCN server.