Head-of-Queue Lifetime Limit

Head-of-queue (HoQ) lifetime limit (HLL) is a mechanism which allows discarding packets attempting to be transmitted after HLL time from the time that they were ready to be transmitted at the head of the scheduling group.

When HLL_packet2Stall (7 as default) packets encounter HLL drop, the scheduling group enters a stall state. During that state all packets to the sub-group are discarded. The subgroup exits stall state after HLL_time*8.

A counter called HoQ discard packets counts the number of discarded packets due to HLL.

HoQ Commands

hll

	hll <max-time> no hll Configures HLL time on this interface. The no form of the command resets HLL time to its default value.
Syntax Description	max-time	Possible values: <4 \| 16 \| 32 \| 64 \| 128 \| 256 \| 512>ms <1 \| 2>sec “inf” to disable HLL
Default	512ms
Configuration Mode	config interface ethernet config interface port-channel config interface mlag-port-channel
History	3.6.5000
Example	switch (config interface ethernet 1/10)# hll 512ms
Related Commands
Notes