TRENDnet TL2-FG142, Руководство пользователя

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TRENDnet User’s Guide
TL2-FG142
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4.3.19.2 LLDP-MED
LLDP-MED is an extension of IEEE 802.1ab and is defined by the telecommunication
industry association (TIA-1057). This page allows you to configure the LLDP-MED. This
function applies to VoIP devices which support LLDP-MED.
Fast start repeat count
Items Description
Fast start
repeat count Rapid startup and Emergency Call Service Location Identification
Discovery of endpoints is a critically important aspect of VoIP systems in
general. In addition, it is best to advertise only those pieces of
information which are specifically relevant to particular endpoint types
(for example only advertise the voice network policy to permitted voice-
capable devices), both in order to conserve the limited LLDPU space and
to reduce security and system integrity issues that can come with
inappropriate knowledge of the network policy.
With this in mind LLDP-MED defines an LLDP-MED Fast Start interaction
between the protocol and the application layers on top of the protocol,
in order to achieve these related properties. Initially, a Network
Connectivity Device will only transmit LLDP TLVs in an LLDPDU. Only
after an LLDP-MED Endpoint Device is detected, will an LLDP-MED
capable Network Connectivity Device start to advertise LLDP-MED TLVs
in outgoing LLDPDUs on the associated port. The LLDP-MED application
will temporarily speed up the transmission of the LLDPDU to start within
a second, when a new LLDP-MED neighbour has been detected in order
share LLDP-MED information as fast as possible to new neighbours.
Because there is a risk of an LLDP frame being lost during transmission
between neighbours, it is recommended to repeat the fast start
transmission multiple times to increase the possibility of the neighbours
receiving the LLDP frame. With Fast start repeat count it is possible to
specify the number of times the fast start transmission would be
repeated. The recommended value is 4 times, given that 4 LLDP frames
with a 1 second interval will be transmitted, when an LLDP frame with
new information is received.
It should be noted that LLDP-MED and the LLDP-MED Fast Start
mechanism is only intended to run on links between LLDP-MED Network
Connectivity Devices and Endpoint Devices, and as such does not apply
to links between LAN infrastructure elements, including Network
Connectivity Devices, or other types of links.
Coordinates Location
Items Description
Latitude Latitude SHOULD be normalized to within 0-90 degrees with a maximum
of 4 digits.
It is possible to specify the direction to either North of the equator or
South of the equator.