GS-4012F/4024 User’s Guide
Chapter 7 Basic Setting 78
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Table 10 Switch Setup
LABEL DESCRIPTION
VLAN Type Choose 802.1Q or Port Based. The VLAN Setup screen changes depending on
whether you choose 802.1Q VLAN type or Port Based VLAN type in this screen.
See Chapter 8 on page 84 for more information.
Bridge Control
Protocol
Transparency
Select Active to allow the switch to handle bridging control protocols (STP for
example). You also need to define how to treat a BPDU in the Port Setup screen.
MAC Address
Learning
MAC address learning reduces outgoing traffic broadcasts. For MAC address
learning to occur on a port, the port must be active.
Aging Time Enter a time from 10 to 3000 seconds. This is how long all dynamically learned MAC
addresses remain in the MAC address table before they age out (and must be
relearned).
GARP Timer: Switches join VLANs by making a declaration. A declaration is made by issuing a Join
message using GARP. Declarations are withdrawn by issuing a Leave message. A Leave All message
terminates all registrations. GARP timers set declaration timeout values. See the chapter on VLAN
setup for more background information.
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. See the chapter on VLAN setup 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.
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.
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 next two 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.
