sdX

SDX, or Software-Defined Exchange, is a platform at Internet Exchange Points that applies software-defined networking and network virtualization to interconnect networks under programmable control. It aims to enable more dynamic, policy-driven peering between participants and to simplify traffic engineering across multiple networks compared with traditional BGP-based peering.

Typically, an SDX provides a centralized control plane and abstracted interfaces (APIs) that tenants can use to provision interconnections with other networks, services, or clouds. Through these controls, customers can create virtual circuits, apply routing or traffic policies, and adjust interconnections in seconds rather than days. The underlying data plane in the IXP fabric carries the traffic, while the control plane programs overlays or underlays to realize the requested paths. Common techniques include overlays such as VXLAN or EVPN and, in some designs, MPLS-based tunnels, with adherence to agreed security and isolation requirements.

Benefits include faster service provisioning, finer-grained control over interconnection policies, improved traffic engineering and performance, better visibility, and potential cost reductions. SDX can also enable new business models for IXPs, cloud on-ramp services, and content delivery networks.

Challenges involve security and privacy between tenants, scalability of the control plane, governance across multiple networks, interoperability with existing BGP policies, and the need for standardized APIs and metrics. As a concept, SDX remains under development with several proof-of-concept deployments and pilots rather than universal adoption.

See also: Software-defined networking, Internet exchange point, network virtualization, multilateral peering, cloud interconnect.