Traffic-Aware Routing

Let’s consider a network with four routers: A, B, C, and D, connected as follows:
Network Topology:
A ↔ B: Link with 10 ms delay (low traffic).
A ↔ C: Link with 20 ms delay (moderate traffic).
B ↔ D: Link with 15 ms delay (low traffic).
C ↔ D: Link with 30 ms delay (high traffic).

Scenario:

Router A needs to send data to Router D.Without traffic awareness, the routing algorithm might choose the A → C → D path, as it’s statically predefined or appears shortest initially.

Step-by-Step Traffic-Aware Routing Example
1. Real-Time Traffic Monitoring:
The network monitors the current traffic on each link:
A → B: Low traffic (10 ms delay).
A → C: Moderate traffic (20 ms delay).
B → D: Low traffic (15 ms delay).
C → D: High traffic (30 ms delay).

2. Dynamic Path Calculation:
The routing algorithm evaluates available paths:
Path 1: A → B → D
Total delay = 10 ms (A → B) + 15 ms (B → D) = 25 ms.
Path 2: A → C → D
Total delay = 20 ms (A → C) + 30 ms (C → D) = 50 ms.
Based on traffic conditions, the algorithm selects Path 1 (A → B → D) as it has lower total delay.

3. Traffic Redistribution:
The routing system directs data from A to D via B instead of the congested link via C.

Final Routing Decision:
Path Chosen: A → B → D
Reason: Lower delay due to less traffic.

Benefits in this Example:
Reduced Latency:
The data packet reaches D faster through the less congested path.

Efficient Resource Utilization:
Traffic on the overloaded C → D link is minimized.

Improved User Experience:
Applications dependent on low latency (e.g., video conferencing) function smoothly.

Real-Life Example:

In the Google Cloud Platform, traffic-aware routing is implemented to redirect user traffic across the least congested data centers. If one data center experiences high traffic or failures, the system dynamically reroutes traffic to another, ensuring fast and reliable service.