Rate controlled opitcal burst switching

摘要

The invention provides a method and network communication equipment for low latency loss-free burst switching. Burst-transfer schedules are determined by controllers of bufferless core nodes according to specified bitrate allocations and distributed to respective edge nodes. In a composite-star network, burst schedules are initiated by any core node. Burst formation takes place at source edge nodes and a permissible burst size is determined according to an allocated bitrate of a burst stream to which the burst belongs. The permissible burst size is subject to constraints such as permissible burst-formation delay, a minimum guard-time requirement, and permissible delay jitter. A method of control-burst exchange between each edge node and each bufferless core node enables burst scheduling, time coordination, and loss-free burst switching. Both the payload bursts and control bursts are carried by optical channels connecting the edge nodes and the core notes.

主权项

1. A method of burst switching in a communication network having a plurality of core switching nodes and a plurality of edge nodes, each core switching node comprising at least one optical switch having no traffic buffers, the method comprising:
receiving, from an edge node at a selected core switching node, a bit rate allocation request specifying a destination edge node; generating, by the selected core switching node in response to the bit allocation request, at least one burst transfer permit, each burst transfer permit specifying a respective permissible burst size, an inter-burst interval and the destination edge node, the respective permissible burst size having:
an upper bound constrained by a maximum jitter tolerance of data constituting data bursts received from the edge node; anda lower bound much larger than a time required for reconfiguring the at least one optical switch and a maximum arrival time error for data bursts arriving at the at least one optical switch; and sending the at least one burst transfer permit by the selected core switching node to the edge node.