Software-Defined Networks for Optical Networks Using Flexible Orchestration: Advances, Challenges, and Opportunities
Table 4
SDN protocols.
Protocol
Description/function
OpenFlow protocol
The OpenFlow protocol [34, 35] governs the relationship and interactions between the “control plane,” which is a controller, and the data plane that serves as a unit for switching in this protocol. The most software-defined network is primarily based on packet flows, which are defined by matching the packet fields defined in the description of the OpenFlow protocol. This is the most common protocol and the most utilised
Path computation element “(PCEP)” protocol
The protocol facilitates the coordination of network elements that occurs with “path computation client (PCC)” and controller’s path computation element (PCE). The paths are computed centrally by the PCE using constraints obtained from the network components. The PCEP is then used to forward the computed paths to individual network components [36, 37]
Network configuration (NETCONF) protocol
On a network computer, the NETCONF protocol [38] offers procedures for configuring, modifying, and deleting settings. The data and protocol messages are configured using an extensible markup language in the NETCONF protocol (XML). The NETCONF protocol procedures are implemented using remote process calls. As a result, the NETCONF protocol can only remotely change system settings on devices that have the required remote procedure calls allowed
Border gateway protocol link state distribution protocol (BGP-LS)
This protocol optimizes end-to-end route computing, and it is very essential in this protocol for the centralized management and possesses the needed information about the network topology inside a database. This database is referred to as “traffic engineering database (TED).” The controller must request information from the network elements via SBIs to construct the traffic engineering database, e.g., utilisation or throughput. These data are available in a variety of formats
