107
Parameter
Description
Fast start repeat count
Rapid Startup and Emergency Call Service Location Identification Discovery of
endpoints are critical
aspects 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). This conserves the limited LLDPU space, and reduces security and system
integrity issues that can come with inappropriate knowledge of the network policy.
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 a 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 share LLDP
-
MED information as fast as possible
to new neighbors.
Because there is a risk of losing a LLDP frame 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
when an LLDP frame with
new information is received, given that 4 LLDP frames with a 1 second interval will
be transmitted
.
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. It 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:
Longitude
should
be normalized to within 0
-
180 degrees with a
maximum of 4 digits.
It is possible to specify the direction to either East of the prime
meridian or West of the prime meridian.
Altitude:
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).
Meters
: Represents meters of altitude defined by the vertical datum
specified.
Floors
: Represents 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. It 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.
