Filter
Top Products
724-746-5500 | blackbox.com
724-746-5500 | blackbox.com
Page 95
Chapter 3: Configuration
Figure 3-44. The LLDP-MED Configuration screen.
Figure 3-45 The LLDP-MED Configuration Policies screen .
Parameter Description Fast start repeat count
The Rapid startup and Emergency Call Service Location Identification Discovery of endpoints are critically important aspects of
VoIP systems. It is best to advertise only those pieces of information that are specifically relevant to particular endpoint types (for
example only advertise the voice network policy to permitted voice-capable devices), both 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 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 neighbor has been detected to 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, Black Box recommends that you
repeat the fast start transmission multiple times to increase the possibility of the neighbors receiving the LLDP frame. With the fast
start repeat count selection, it is possible to specify the number of times the fast start transmission would be repeated. The rec-
ommended 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.
NOTE: The LLDP-MED and the LLDP-MED Fast Start mechanism are only intended to run on links between LLDP-MED Network
connectivity Devices and Endpoint Devices, and as such do not apply to links between LAN infrastructure elements, including
network connectivity devices, or other types of links.
LGB1108A