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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 only transmits 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
Fast start
outgoing LLDPDUs on the associated port. The LLDP-MED application temporarily
repeat count
speeds up the transmission of the LLDPDU to start within a second, when a new LLDP-
MED neighbor has been detected in order 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, it is recommended to repeat 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 4 times, given that 4 LLDP frames with a 1 second
interval are 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
Latitude SHOULD be normalized to within 0-90 degrees with a maximum of 4 digits.
Latitude
It is possible to specify the direction to either North of the equator or South of the
equator.
Longitude SHOULD be normalized to within 0-180 degrees with a maximum of 4 digits.
Longitude
It is possible to specify the direction to either East of the prime meridian or West of the
prime meridian.
Altitude SHOULD be normalized to within -32767 to 32767 with a maximum of 4 digits.
It is possible to select between two altitude types (floors or meters).
•
Altitude
•
RocketLinx MP1204-XT User Guide: 2000644 Rev. A
Configuration | LLDP | LLDP-MED
Meters: Representing meters of Altitude defined by the vertical datum specified.
Floors: Representing altitude in a form more relevant in buildings which have
different floor-to-floor dimensions. An altitude = 0.0 is meaningful even outside a
building, and represents ground level at the given latitude and longitude. Inside a
building, 0.0 represents the floor level associated with ground level at the main
entrance.
LLDP | LLDP-MED
Configuration Pages - 135
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