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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
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.
Longitude :
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