Optical Systems Design OSD2524, User Manual

Page: 164 / 402

OPTICAL SYSTEMS DESIGN
DOC ID: 10120001
OSD2524 OPERATOR MANUAL
PAGE 164
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 interface. 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 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 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.
TRANSMIT TLVS
It is possible to select which LLDP-MED information that shall be transmitted to the neighbors. When
the checkbox is checked the information is included in the frame transmitted to the neighbor.
Interface
The interface name to which the configuration applies.
Capabilities
When checked the switch's capabilities is included in LLDP-MED information transmitted.
Policies
When checked the configured policies for the interface is included in LLDP-MED information
transmitted.
Location
When checked the configured location information for the switch is included in LLDP-MED information
transmitted.
PoE