Исходное сообщение
"Понимание порогов сброса в L2 QOS" Отправлено gfh1gfh1, 26-Апр-19 08:47
The buffer space is divided between the common pool and the reserved pool. The switch uses a buffer allocation scheme to reserve a minimum amount of buffers for each egress queue, to prevent any queue or port from consuming all the buffers and depriving other queues, and to control whether to grant buffer space to a requesting queue. The switch detects whether the target queue has not consumed more buffers than its reserved amount (under-limit), whether it has consumed all of its maximum buffers (over limit), and whether the common pool is empty (no free buffers) or not empty (free buffers). If the queue is not over-limit, the switch can allocate buffer space from the reserved pool or from the common pool (if it is not empty). If there are no free buffers in the common pool or if the queue is over-limit, the switch drops the frame. ... enable a queue in the full condition to obtain more buffers than are reserved for it. This is the maximum memory the queue can have before the packets are dropped if the common pool is not empty. The range is 1 to 3200 percent. Грубо говоря есть резервированный объем памяти для исходящих очередей (для каждой) и общий набор памяти для всех исходящих очередей. Можно задавать пороги сброса (drop-threshold) до 32-х раз больше чем резервированный объем памяти очереди.