Cisco 7821, Руководство администратора

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The Port ID TLV is mandatory as the second TLV. Only one Port ID TLV is allowed for the outgoing and
incoming LLDPDUs.
Time to Live TLV
For the outgoing LLDPDU, the Time to Live TTL value is 180 seconds. This differs from the 120-second
value that the standard recommends. For the shutdown LLDPDU, the TTL value is always 0.
The Time to Live TLV is mandatory as the third TLV. Only one Time to Live TLV is allowed for the outgoing
and incoming LLDPDUs.
End of LLDPDU TLV
The value is 2-octet, all zero. This TLV is mandatory and only one is allowed for the outgoing and incoming
LLDPDUs.
Port Description TLV
For the outgoing LLDPDU, in the Port Description TLV, the value for the port description is the same as
“Port ID TLV” for CDP. The incoming LLDPDU, the Port Description TLV, is ignored and not validated.
Only one Port Description TLV is allowed for outgoing and incoming LLDPDUs.
System Name TLV
For the Cisco IP Phone, the value is SEP+MAC address.
Example: SEPAC44F211B1D0
The incoming LLDPDU, the System Name TLV, is ignored and not validated. Only one System Name TLV
is allowed for the outgoing and incoming LLDPDUs.
System Capabilities TLV
For the outgoing LLDPDU, in the System Capabilities TLV, the bit values for the 2 octet system capabilities
fields should be set for Bit 2 (Bridge) and Bit 5 (Phone) for a phone with a PC port. If the phone does not
have a PC port, only Bit 5 should be set. The same system capability value should be set for the enabled
capability field.
For the incoming LLDPDU, the System Capabilities TLV is ignored. The TLV is not validated semantically
against the MED device type.
The System Capabilities TLV is mandatory for outgoing LLDPDUs. Only one System Capabilities TLV is
allowed.
Management Address TLV
The TLV identifies an address associated with the local LLDP agent (that may be used to reach higher layer
entities) to assist discovery by network management. The TLV allows the inclusion of both the system interface
number and an object identifier (OID) that are associated with this management address, if either or both are
known.
• TLV information string length—This field contains the length (in octets) of all the fields in the TLV
information string.
• Management address string length—This field contains the length (in octets) of the management address
s management address fields.
Cisco IP Phone 7800 Series Multiplatform Phones Administration Guide
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Cisco IP Phone Installation
Time to Live TLV