Overlay network

[citation needed] Overlay networks have a certain set of attributes, including separation of logical addressing, security and quality of service.

From an enterprise point of view, while an overlay VPN service configured by the operator might fulfill their basic connectivity requirements, they lack flexibility.

DiffServ itself provides no guarantee of throughput, it does allow the network operator to decide which traffic is higher priority, and hence will be forwarded first in congestion situations.

For example, Akamai Technologies manages an overlay network that provides reliable, efficient content delivery (a kind of multicast).

The objective of resilience in telecommunications networks is to enable automated recovery during failure events in order to maintain a wanted service level or availability.

The advantage of overlays are that they are more flexible/programmable than traditional network infrastructure, which outweighs the disadvantages of additional latency, complexity and bandwidth overheads.

Resilient Overlay Networks (RON) are architectures that allow distributed Internet applications to detect and recover from disconnection or interference.

Throughout the last decade, a number of research projects have explored the use of multicast as an efficient and scalable mechanism to support such group communication applications.

Multicast decouples the size of the receiver set from the amount of state kept at any single node and potentially avoids redundant communication in the network.

All multicast-related functionality is implemented at the peers instead of at routers, and the goal of the multicast protocol is to construct and maintain an efficient overlay for data transmission.