76System configuration software features

port ID TLV

Time to Live TLV

End Of LLDPDU TLV

The chassis ID and the port ID values are concatenated to form a logical MSAP identifier that is used by the recipient to identify the sending LLDP agent and port.

A non-zero value in the Time to Live (TTL) field of the TTL TLV indicates to the receiving LLDP agent how long the LLDPDU information from the MSAP identifier remains valid. All LLDPDU information is automatically discarded by the receiving LLDP agent if the sender fails to update it in a timely manner. A zero value in TTL field of Time To Live TLV tells the receiving LLDP agent to discard the information associated with the LLDPDU MSAP identifier.

In addition to the four mandatory TLVs, Release 4.1 software supports the basic management TLV set. You can specify which of these optional TLVs to include in the transmitted LLDPDUs for each port.

The optional management TLVs are as follows:

Port Description TLV

System Name TLV

System Description TLV

System Capabilities TLV (indicates both the system supported capabilities and enabled capabilities, such as end station, bridge, or router)

Management Address TLV

Transmitting LLDPDUs When a transmit cycle is initiated, the LLDP manager extracts the managed objects from the LLDP local system MIB and formats this information into TLVs. The TLVs are then inserted into the LLDPDU.

LLDPDUs are regularly transmitted at a user-configurable transmit interval (tx-delay), or when any of the variables contained in the LLPDU are modified on the local system (such as system name or management address). Tx-delay is the minimum delay between successive LLDP frame transmissions.

TLV system MIBs The LLDP local system MIB stores the information for constructing the various TLVs to be sent. The LLDP remote system MIB stores the information received from remote LLDP agents.

Nortel Ethernet Routing Switch 2500 Series

Overview — System Configuration

NN47215-500 (323162-B) 02.02 Standard

4.1 19 November 2007

Copyright © 2007, Nortel Networks

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Nortel Networks 2500 Series manual System configuration software features