User`s guide

VigorSwitch P2261 User’s Guide
99
Parameters description:
Fast start repeat count
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.