NETGEAR S3300-28X (GS728TX) 24x1GE - Инструкция по эксплуатации - Страница 202

Configuring Switching 

202

S3300 Smart Managed Pro Switch 

802.1AS

1

Note:

The 802.1AS feature is only supported on a standalone S3300 switch. 
Standalone here means that all four stack ports are running in 
Ethernet mode.

The IEEE 802.1AS standard specifies the protocol and procedures used to ensure that the 
QoS requirements are guaranteed for time-sensitive applications, such as audio and video. 
The IEEE 1588 Precision Time Protocol (PTP) forms the basis of the IEEE 802.1AS 
standard. PTP specifies a precise clock synchronization protocol that relies on time-stamped 
packets. The PTP protocol is applicable to distributed systems consisting of one or more 
nodes communicating over some set of communication media. The distribution of 
synchronous time information is performed in a hierarchical manner with a grandmaster clock 
at the root of the hierarchy. The grandmaster provides a common and precise time reference 
for one or more directly-attached slave devices by periodically exchanging timing information. 
In other words, all slave devices synchronize their clocks with the grandmaster clock. The 
slave devices can, in-turn, act as master devices for further hierarchical layers of slave 
devices. 

From the 802.1AS link, you can access the following screens:

•

802.1AS Configuration 

•

802.1AS (EAV) in a Stacking Environment 

•

802.1AS Statistics 

802.1AS Configuration

Use the 802.1AS Configuration screen to enable the 802.1AS mode on the switch and 
configure local clock priorities. The 802.1AS feature calculates the time delay between 
devices on a given link and maintains an accurate view of a network clock.The screen also 
displays various global 802.1AS information. 



To configure the global 802.1AS settings on the switch:

1. 

Select 

Switching

 > 

802.1AS 

>

 Basic

  >

 802.1AS Configuration

.

2. 

Next to 802.1AS status, select 

Enable

. 

3. 

In the Local Clock Priority1 field, specify the Priority1 value of the local clock (this time-aware 
bridge).

4. 

In the Local Clock Priority2 field, specify the Priority2 value of the local clock (this time-aware 
bridge).

5. 

Click the 

Apply

 button.

1. The 802.1AS feature is available only with a valid license. To activate this feature, you must purchase a license.