BGP (Border Gateway Protocol) is used to establish routes across the Internet. Each network is assigned an AS (Autonomous System) number that uniquely identifies it. Typically AS numbers are assigned to ISPs or organizations with large networks.
The diagram above shows ISPs UUNET, GNN and AOL with AS numbers 701, 1668 and 10593 respectively. Netscape has it's own AS number. Customers A and B share the AS number of their ISP.
In this example we will look at the challenge faced a hosting ISP. The ISP wants to manage its peering relationships in order to improve the connectivity between the servers it hosts and the customers that access them.
The border switch is running BGP. Traffic information from the switch is collected by Traffic Sentinel and is available for analysis. The first chart shows the most active routes in real-time.