Chapter 4: Web management
NS3550-8T-2S Industrial Managed Switch User Manual
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LLDP-MED configuration
The LLDP-MED Configuration page permits configuration of the LLDP-MED.
The page includes the following fields:
Fast start repeat count
Object
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 addition, it is
best to advertise only those pieces of information which are specifically
relevant to particular endpoint types (e.g., 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 neighbor has been detected in order to
share LLDP-MED information as fast as possible to new neighbors.
Because there is a risk of an LLDP frame being lost during transmission
between neighbors, we recommend repeating the fast start transmission
multiple times to increase the possibility of the neighbors 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 four times, given that four LLDP frames with a one second interval
will be transmitted when an LLDP frame with new information is received.