Method and apparatus for implementing a backpressure mechanism in an asynchronous data transfer and source traffic control system
AssigneeTranSwitch Corporation
InventorsRonald P. Novick, Sing Ngee Yeo
Life of this patent
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Abstract
Methods for implementing a backpressure mechanism in an asynchronous data transfer and source traffic control system include detecting when a bus user is experiencing congestion and preventing other bus users from sending cells over the bus. According to a first embodiment, if congestion is detected for two consecutive frames, the arbiter is inhibited from granting access to any bus user for one frame. According to a second embodiment, if congestion is detected during any frame, all the bus users are prevented from transmitting low priority traffic until congestion is absent for four consecutive frames. An apparatus for performing the methods is also disclosed.
Claims8
A method for implementing a backpressure mechanism in an asynchronous data transfer and source traffic control system having a data bus and a plurality of bus users where data is transferred over the bus in a repeating frame, some data is high priority and other data is low priority, said method comprising:
- a) detecting a congestion condition;
- b) barring low priority data access to the bus following the detection of a congestion condition;
- and
- c) permitting low priority traffic following four consecutive frames during which no congestion is detected.
An apparatus for implementing a backpressure mechanism in an asynchronous data transfer and source traffic control system having a data bus and a plurality of bus users where data is transferred over the bus in a repeating frame, some data is high priority and other data is low priority, said method comprising:
- a) detection means for detecting a congestion condition;
- and
- b) access control means barring low priority data access to the bus following the detection of a congestion condition, wherein
- said access control means removes the bar to low priority traffic following four consecutive frames during which no congestion is detected by the detection means.
Dependencies are inferred from the claim text.