ZyXEL Communications MSC1000G Series, Руководство пользователя

Страница: 516 / 1168

Chapter 13 Switch Screens
Management Switch Card User’s Guide
516
13.6 Switch Setup Dot3ad Screen
Click Switch > Switch Setup > Dot3ad to display the screen as shown.
Leave All Timer Leave All Timer sets the duration of the Leave All Period timer for GVRP in milliseconds.
Each port has a single Leave All Period timer. Leave All Timer must be larger than Leave
Timer; the default is 1000 milliseconds.
Priority Queue Assignment
IEEE 802.1p defines up to 8 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 drop-down list boxes to configure the priority level-to-physical queue mapping.
The system has 8 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 Levels (The following descriptions are based on the traffic types defined in the IEEE 802.1d standard
(which incorporates IEEE 802.1p).
Priority 7 Typically used for network control traffic such as router configuration messages.
Priority 6 Typically used for voice traffic that is especially sensitive to jitter (jitter is the variations in
delay).
Priority 5 Typically used for video that consumes high bandwidth and is sensitive to jitter.
Priority 4 Typically used for controlled load, latency-sensitive traffic such as SNA (Systems Network
Architecture) transactions.
Priority 3 Typically used for “excellent effort” or better than best effort and would include important
business traffic that can tolerate some delay.
Priority 2 This is for “spare bandwidth”.
Priority 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.
Priority 0 Typically used for best-effort traffic.
Aging Time Enter a time from 10 to 10,000 seconds. This is how long all dynamically learned MAC
addresses remain in the MAC address table before they age out (and must be relearned).
Enter 0 to disable the aging out of MAC addresses.
This setting applies to both the MSC and any installed ELCs.
Apply Click Apply to save the changes in this screen to the system’s volatile memory. The system
loses these changes if it is turned off or loses power, so use the Config Save link on the
navigation panel and then the Save button to save your changes to the non-volatile
memory when you are done configuring.
Cancel Click Cancel to begin configuring this screen afresh.
Table 270
Switch Setup General (continued)
LABEL DESCRIPTION