VoIP/VoLTE: Indirect correlating of SIP and RTP while tapping on 3g and 4g networks
Publication Date: 2016-May-19
The IP.com Prior Art Database
Probing solution are usually deployed between SGW/PGW (SGSN/GGSN), thus not getting the dedicated VoLTE traffic, but all data generated by customer devices. The main requirement, put by customer, is to account for all transaction made by user device and product KPIs, which can help to outline customer experience, operator core network performance, as well as provide the necessary information to apply various analytics for operator. In particular for VoLTE probing module, probe need to be able to correlate every single RTP packet to its SIP initiator in order to calculate KPIs for the voice call. The main KPIs definitions are coming from customer requirements on getting visibility on over voice call, starting from how call started, how long it went and what was a quality and how finished. The main difficulties with probing solution are the following: - identify the protocols with in data flow - parse the protocol in fast and effective way - correlate all corresponding flows belongs to the - Particular user endpoint, - Particular application on user device - Particular transaction for the application - Particular data flow (UDP/TCP/SCTP) - Provide the solution for data feeds exceeding the 10GBits/sec This article will outline the specific technique used to solve the correlation for VoLTE traffic, presented by SIP/RTP, but it is extendable to any other methods how voice call can be initiated (HTTP. RTSP etc).