Capability
Bit Position
LLDP-MED Capabilities
0
Network Policy
1
Extended Power via MDI-PD
4
Inventory
5
For the incoming TLV, if the LLDP-MED TLV is not present, the LLDPDU is discarded. The LLDP-MED
Capabilities TLV is mandatory and only one is allowed for the outgoing and incoming LLDPDUs. Any other
LLDP-MED TLVs will be ignored if they present before the LLDP-MED Capabilities TLV.
Network Policy TLV
In the TLV for the outgoing LLDPDU, before the VLAN or DSCP is determined, the Unknown Policy Flag
(U) is set to 1. If the VLAN setting or DSCP is known, the value is set to 0. When the policy is unknown, all
other values are set to 0. Before the VLAN is determined or used, the Tagged Flag (T) is set to 0. If the tagged
VLAN (VLAN ID > 1) is used for the phone, the Tagged Flag (T) is set to 1. Reserved (X) is always set to
0. If the VLAN is used, the corresponding VLAN ID and L2 Priority will be set accordingly. VLAN ID valid
value is range from 1-4094. However, VLAN ID=1 will never be used (limitation). If DSCP is used, the value
range from 0-63 is set accordingly.
In the TLV for the incoming LLDPDU, Multiple Network Policy TLVs for different application types are
allowed.
LLDP-MED Extended Power-Via-MDI TLV
In the TLV for the outgoing LLDPDU, the binary value for Power Type is set to “0 1” to indicate the power
type for phone is PD Device. The Power source for the phone is set to “PSE and local” with binary value “1
1”. The Power Priority is set to binary “0 0 0 0” to indicate unknown priority while the Power Value is set to
maximum power value. The Power Value for the Cisco IP Phone is 12900mW.
For the incoming LLDPDU, the TLV is ignored and not validated. Only one TLV is allowed in the outgoing
and incoming LLDPDUs. The phone will send out the TLV for the wired network only.
The LLDP-MED standard was originally drafted in the context of Ethernet. Discussion is ongoing for
LLDP-MED for Wireless Networks. Refer to ANSI-TIA 1057, Annex C, C.3 Applicable TLV for VoWLAN,
table 24. It is recommended that the TLV is not applicable in the context of the wireless network. This TLV
is targeted for use in the context of PoE and Ethernet. The TLV, if added, will not provide any value for
network management or power policy adjustment at the switch.
LLDP-MED Inventory Management TLV
This TLV is optional for Device Class III. For the outgoing LLDPDU, we support only Firmware Revision
TLV. The value for the Firmware Revision is the version of firmware on the phone. For the incoming LLDPDU,
the TLVs are ignored and not validated. Only one Firmware Revision TLV is allowed for the outgoing and
incoming LLDPDUs.
Cisco IP Phone 7800 Series Multiplatform Phones Administration Guide
49
Cisco IP Phone Installation
Network Policy TLV