System Description TLV
The TLV allows the network management to advertise the system description.
• TLV information string length—This field indicates the exact length (in octets) of the system description.
• System description—This field contains an alphanumeric string that is the textual description of the
network entity. The system description includes the full name and version identification of the system
hardware type, software operating system, and networking software. If implementations support IETF
RFC 3418, the sysDescr object should be used for this field.
IEEE 802.3 MAC/PHY Configuration/Status TLV
The TLV is not for autonegotiation, but for troubleshooting purposes. For the incoming LLDPDU, the TLV
is ignored and not validated. For the outgoing LLDPDU, for the TLV, the octet value autonegotiation
support/status should be:
• Bit 0—Set to 1 to indicate that the autonegotiation support feature is supported.
• Bit 1—Set to 1 to indicate that autonegotiation status is enabled.
• Bit 2-7—Set to 0.
The bit values for the 2 octets PMD autonegotiation advertised capability field should be set to:
• Bit 13—10BASE-T half duplex mode
• Bit 14—10BASE-T full duplex mode
• Bit 11—100BASE-TX half duplex mode
• Bit 10—100BASE-TX full duplex mode
• Bit 15—Unknown
Bit 10, 11, 13 and 14 should be set.
The value for 2 octets operational MAU type should be set to reflect the real operational MAU type:
• 16—100BASE-TX full duplex
• 15—100BASE-TX half duplex
• 11—10BASE-T full duplex
• 10—10BASE-T half duplex
For example, usually, the phone is set to 100BASE-TX full duplex. The value 16 should then be set. The TLV
is optional for a wired network and not applicable for a wireless network. The phone sends out this TLV only
when in wired mode. When the phone is not set for autonegotiation but specific speed/duplexity, for the
outgoing LLDPDU TLV, bit 1 for the octet value autonegotiation support/status should be clear (0) to indicate
that autonegotiation is disabled. The 2 octets PMD autonegotiation advertised capability field should be set
to 0x8000 to indicate unknown.
LLDP-MED Capabilities TLV
For the outgoing LLDPDU, the TLV should have the device type 3 (End Point Class III) with the following
bits set for 2-octet Capability field:
Cisco IP Phone 7800 Series Multiplatform Phones Administration Guide
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Cisco IP Phone Installation
System Description TLV
