SIP Sedation Server for Network Congestion Management
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional telecommunications network configurations face congestion and instability when a service-providing node fails, leading to a flood of messages and potential network overload, especially in large subscriber networks using protocols like SIP.
Innovation Solution
A sedation server is introduced to act on behalf of an unavailable SIP server, sending messages to user agents to reduce the frequency and number of messages sent, using sedation messages with a 'retry after' parameter to distribute retry requests over time, thereby preventing network overload and congestion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a service-providing node fails, then message traffic from service clients increases as they attempt to re-establish sessions, but this results in network congestion and potential node overload
Solution Approach 1:
A sedation server is introduced as an intermediary component that sits between the failing service node and the client user agents. The sedation server intercepts registration requests from clients, manages the retry logic, and controls the flow of messages to prevent flooding the recovering node while still allowing session re-establishment to proceed reliably
Solution Approach 2:
The sedation server performs preliminary actions by pre-configuring retry parameters and establishing a structured retry mechanism before the node recovers. It proactively manages the retry process by implementing exponential backoff and maximum retry limits, preventing the chaotic message flood that would otherwise occur when clients independently attempt reconnection
2Productivity
If a failing node recovers, then it can resume serving clients, but the flood of messages directed to the node may overwhelm it and cause further congestion
Solution Approach 1:
The sedation server implements periodic action through controlled retry intervals using exponential backoff algorithms. Instead of allowing clients to flood the recovering node immediately, it enforces periodic retry attempts with increasing intervals between messages, distributing the load over time and preventing node overload while still enabling service resumption
Solution Approach 2:
The retry mechanism is made dynamic by implementing exponential backoff and maximum retry limits that adapt based on the recovery progress. The sedation server dynamically adjusts the retry behavior, starting with more frequent attempts and gradually reducing frequency, while stopping entirely when maximum retries are reached, thus preventing indefinite congestion
3Reliability
If the protocol allows multiple reconnection retries, then clients can attempt to re-establish sessions, but the increase in congestion may continue indefinitely
Solution Approach 1:
Maximum retry limits are established as a preliminary constraint before the retry process begins. The sedation server pre-configures the maximum number of retry attempts allowed, ensuring that even if a node fails for an extended period, the message flood will be automatically curtailed after a predetermined number of attempts, preventing indefinite congestion
Solution Approach 2:
Exponential backoff is applied to create periodic retry intervals that increase over time. This transforms the retry process from a continuous flood into a structured periodic sequence where the time between attempts grows exponentially, naturally limiting the total duration of congestion while still providing multiple reconnection opportunities
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
Methods, systems, and computer readable media tor providing sedation service in a telecommunications network are disclosed. According to one aspect, a method for providing sedation service in a telecommunications network is provided. The method includes steps that are performed at a session initiation protocol (SIP) sedation node. The method includes receiving a first message sent from a SIP user agent and intended for a SIP server. The method further includes determining whether the SIP server is unavailable. The method further includes responsive to a determination that the SIP server is unavailable to respond to the first message, sending, to the SIP client, a SIP sedation message for reducing the number or frequency of messages sent by the SIP user agent to the SIP server.