Packet Broker IMS Traffic Correlation and Load Balancing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional packet brokers struggle to correlate and load balance IMS traffic from IMS core networks due to the lack of unique user, device, or session identifiers, which are necessary for analyzing IMS sessions involving multiple users and multiple public identities.
Innovation Solution
A packet broker device with an IMS correlation and load balancing module that generates unique session IDs based on FROM and TO headers in IMS control and data traffic, and uses these IDs for correlation and load balancing across analytic probes/tools, while maintaining mappings between public and private identities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional packet brokers use unique user/device identifiers (IMSI, IMEI) for correlation and load balancing as in GTP networks, then correlation and load balancing work effectively for GTP traffic, but this approach fails for IMS traffic because IMS sessions involve multiple users and multiple public identities without a single unique identifier
Solution Approach 1:
The patent segments the identification problem by creating separate identifier components for different IMS traffic types. Control traffic (SIP) uses call-IDs as identifiers, while data traffic (RTP) uses SSRC identifiers from SDP headers. This segmentation allows each traffic type to be correlated using its native identifier scheme rather than forcing a single identifier type on both.
Solution Approach 2:
The patent introduces an intermediary mapping mechanism that connects control traffic identifiers (call-IDs) with data traffic identifiers (SSRCs). The packet broker maintains associations between these different identifier types, enabling correlation across traffic types without requiring a single universal identifier. This intermediary layer translates between different identification schemes.
2Measurement precision
If packet brokers attempt to correlate IMS control and data traffic using existing identifiers, then some correlation may be achieved, but accurate per-session correlation fails because call-IDs and SSRCs do not directly correspond without additional mapping information
Solution Approach 1:
The patent performs preliminary actions by establishing identifier mappings during the IMS session setup phase. When the packet broker observes SIP signaling messages during call establishment, it proactively creates and stores the associations between call-IDs and SSRCs before actual media traffic flows. This preliminary mapping preparation eliminates the need for complex real-time correlation algorithms during traffic analysis.
Solution Approach 2:
The patent implements feedback mechanisms where the packet broker continuously monitors IMS signaling traffic to update and maintain the call-ID to SSRC mappings. As new signaling messages are observed, the system feedbacks into the mapping table to refresh or add associations, ensuring the correlation data remains current and accurate throughout the session lifecycle.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Techniques for correlating and load balancing IMS traffic in a visibility network are provided. According to one set of embodiments, a packet broker of the visibility network can receive IMS traffic replicated from an IMS core network and identify control/data packets in the IMS traffic that are part of the same IMS session based on FROM and TO user identities included in the packets. The packet broker can then generate a unique session identifier for the IMS session and add the generated session identifier to the packets. In certain embodiments, the packet broker can further provide the generated session identifier as input to a load balancing algorithm or rule set. The load balancing algorithm or rule set can output an egress port of the packet broker through which the control/data packets should be forwarded based on the session identifier.