Method and apparatus for adaptive fast start in link aggregation
AssigneeCisco Technology, Inc.
InventorsYuchen Zhou, Chia Alex Tsai, Yibin Yang, Rajagopalan Janakiraman
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Abstract
In one embodiment, a period between periodic transmissions of protocol data units (PDUs) used to form or maintain a link aggregation group is initially set to a fixed value. When a stress condition is detected, the period between periodic transmissions of PDUs is increased from the initial value. When the stress condition is determined to have eased, the period between periodic transmissions of PDUs is reduced back toward the fixed value.
Claims17
A method comprising:
- initially setting a time period between periodic transmissions of protocol data units (PDUs) used to form or maintain a link aggregation group to a fixed value;
- detecting, by a network device, a stress condition affecting the link aggregation group, wherein the detecting the stress condition further comprises:
- monitoring a completion time of one or more individual aggregation operations;
- and
- using the completion time to detect the stress condition;
- in response to detecting the stress condition, increasing the time period between periodic transmissions of PDUs by a selected amount from the initial fixed value;
- determining, by the network device, that the stress condition has eased;
- and
- in response to determining that the stress condition has eased, decreasing the time period between periodic transmissions of PDUs by a selected amount back toward the initial fixed value.
An apparatus, comprising:
- one or more line cards that support a plurality of ports coupled to links;
- a processor coupled to the one or more line cards and configured to execute software processes;
- a link aggregation engine configured to form a link aggregation group that includes two or more of the links, and to periodically exchange protocol data units (PDUs) with a partner at an opposing end of the links of the link aggregation group;
- a system condition detector configured to detect occurrence of a stress condition, monitor one or more protocol timers, and detect a stress condition in response to expiration of the one or more protocol timers, wherein the one or more protocol timers include a PDU receipt timer that runs for a timeout time within which a PDU is expected to be received;
- and
- an adaptive controller configured to increase a time period between the periodic exchange of PDUs by a selected amount in response to occurrence of the stress condition, and to decrease the time period between periodic transmissions of PDUs by a selected amount, in response to easing of the stress condition.
Software encoded on one or more non-transitory computer-readable media and when executed operable to:
- initially set a time period between periodic transmissions of protocol data units (PDUs) used to form or maintain a link aggregation group to a fixed value;
- detect a stress condition affecting the link aggregation group by:
- monitoring a completion time of one or more individual aggregation operations;
- and
- using the completion time to detect the stress condition;
- in response to detection of the stress condition, increase the time period between periodic transmissions of PDUs by a selected amount from the initial fixed value;
- determine that the stress condition has eased;
- and
- in response to determination that the stress condition has eased, decrease the time period between periodic transmissions of PDUs by a selected amount back toward the initial fixed value.
Dependencies are inferred from the claim text.