Table of Contents
Advertisement
The page includes the following fields:
Fast start repeat count
Object
Fast start repeat count
User's Manual of GS-5220-24T4XV(R) Managed LCD Switch
Figure 4-3-8-2: LLDPMED Configuration Page Screenshot
Description
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
192
Advertisement
Table of Contents
