ZyXEL Communications XGS4700-48F manual 112

Chapter 8 Basic Setting

Table 12 Basic Setting > Switch Setup (continued)

LABEL	DESCRIPTION
Join Timer	Join Timer sets the duration of the Join Period timer for GVRP in
	milliseconds. Each port has a Join Period timer. The allowed Join Time
	range is between 100 and 65535 milliseconds; the default is 200
	milliseconds. See Chapter 9 on page 119 for more background
	information.
Leave Timer	Leave Time sets the duration of the Leave Period timer for GVRP in
	milliseconds. Each port has a single Leave Period timer. Leave Time
	must be two times larger than Join Timer; the default is 600
	milliseconds.
Leave All	Leave All Timer sets the duration of the Leave All Period timer for GVRP in
Timer	milliseconds. Each port has a single Leave All Period timer. Leave All
	Timer must be larger than Leave Timer.

Priority Queue Assignment

IEEE 802.1p defines up to eight separate traffic types by inserting a tag into a MAC-layer frame that contains bits to define class of service. Frames without an explicit priority tag are given the default priority of the ingress port. Use the following fields to configure the priority level-to-physical queue mapping.

The Switch has eight physical queues that you can map to the 8 priority levels. On the Switch, traffic assigned to higher index queues gets through faster while traffic in lower index queues is dropped if the network is congested.

Priority Level (The following descriptions are based on the traffic types defined in the IEEE 802.1d standard (which incorporates the 802.1p).

Level 7	Typically used for network control traffic such as router configuration
	messages.
Level 6	Typically used for voice traffic that is especially sensitive to jitter (jitter is
	the variations in delay).
Level 5	Typically used for video that consumes high bandwidth and is sensitive to
	jitter.
Level 4	Typically used for controlled load, latency-sensitive traffic such as SNA
	(Systems Network Architecture) transactions.
Level 3	Typically used for “excellent effort” or better than best effort and would
	include important business traffic that can tolerate some delay.
Level 2	This is for “spare bandwidth”.
Level 1	This is typically used for non-critical “background” traffic such as bulk
	transfers that are allowed but that should not affect other applications
	and users.
Level 0	Typically used for best-effort traffic.
Apply	Click Apply to save your changes to the Switch’s run-time memory. The
	Switch loses these changes if it is turned off or loses power, so use the
	Save link on the top navigation panel to save your changes to the non-
	volatile memory when you are done configuring.
Cancel	Click Cancel to begin configuring this screen afresh.

112
	XGS4700-48F User’s Guide