GS-4012F/4024 User’s Guide

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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

Select Active to allow the switch to handle bridging control protocols (STP for

Protocol

example). You also need to define how to treat a BPDU in the Port Setup screen.

Transparency

 

MAC Address

MAC address learning reduces outgoing traffic broadcasts. For MAC address

Learning

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 Declarations are withdrawn by issuing a Leave message.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.

Chapter 7 Basic Setting

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