SYSTEMS AND METHODS FOR HARDWARE ACCELERATED TIMER IMPLEMENTATION FOR OPENFLOW PROTOCOL

摘要

A new approach is proposed to support a virtual network switch, which is a software implementation of a network switch utilizing hardware to accelerate implementation of timers of the virtual network switch under OpenFlow protocol. The approach utilizes a plurality of hardware-implemented timer blocks/rings, wherein each of the rings covers a specified time period and has a plurality of timer buckets each corresponding to an interval of expiration time of timers. When a new flow table entry is programmed at an OpenFlow agent of the virtual network switch, its associated timer entries are created and inserted into the corresponding timer bucket based on the expiration time of the timers. During operation, hardware of the virtual network switch traverses the timer rings for the timer bucket which time has expired, identifies timer entries in the expired timer bucket, interrupts CPU or provides a notification to the agent with necessary contextual information.

主权项

1. A system to support hardware accelerated timer implementation for a virtual network switch under OpenFlow protocol, comprising:
an OpenFlow agent configured to:
program and maintain one or more hardware timer rings for the virtual network switch, wherein each of the timer rings includes a plurality of timer buckets each maintaining a plurality of timer entries with expiration time within a time interval;create a set of timer entries for timers of newly created flow table entries under the OpenFlow protocol;insert the set of timer entries into one of the timer buckets in one of the plurality of timer rings, wherein expiration time of the timer bucket corresponds to expiration time of the timers; said hardware timer rings for the virtual network switch each configured to:
traverse the timer entries in a current timer bucket by hardware when current time reaches the expiration time of the timer bucket;schedule notifications to the OpenFlow agent for all of the timer entries in the time bucket that are still valid to perform instructions in the flow table entries associated with the timers.