Software Defined Internet Exchange (SDX)

💡 The Core Idea

SDX applies SDN principles to Internet Exchange Points (IXPs) to fix the limitations of BGP. It allows routing decisions based on Application (e.g., Netflix vs. Email) or Source, rather than just Destination IP.

🧠 Mechanism

• The Illusion: SDX gives each participant AS the illusion of having its own Virtual SDN Switch connecting to all other participants.
• Policies: ASes can write custom policies (using languages like Pyretic) to direct traffic.

🚀 Use Cases

1. Application Specific Peering: Route “High-Bandwidth Video” differently than “VoIP”.
2. Inbound Traffic Engineering: Controlling how traffic enters the network (difficult in traditional BGP).
3. Wide-Area Load Balancing: Redirecting requests to different backend servers by modifying packet headers at the exchange.

🔗 Connections

• Source: Source - SDN Part 2 and Applications