Link Layer Discovery Protocol (LLDP)
Link Layer Discovery Protocol (LLDP)
Link Layer Discovery Protocol (LLDP) is an open standards layer 2 protocol IP Telephones use to advertise their identity and capabilities and to receive administration from an LLDP server. LAN equipment can use LLDP to manage power, administer VLANs, and provide some administration.
The transmission and reception of LLDP is specified in IEEE
9600 Series IP Telephones running SIP Release 2.0 software support IEEE 802.1AB if the value of the configuration parameter LLDP_ENABLED is "1" (On) or "2" (Auto). If the value of LLDP_ENABLED is “0” (off), the transmission and reception of Link Layer Discovery Protocol (LLDP) is not supported. When the value of LLDP_ENABLED is “2”, the transmission of LLDP frames will not begin until or unless an LLDP frame is received, and the first LLDP frame will be transmitted within 2 seconds after the first LLDP frame is received. Once transmission begins, an LLDPDU will be transmitted every 30 seconds.
Note:
There could be a delay of up to 30 seconds in telephone initialization if the file server address is delivered by LLDP and not by DHCP.
These telephones:
●do not support LLDP on the secondary Ethernet interface.
●will not forward frames received with the 802.1AB LLDP group multicast address as the destination MAC address between the Ethernet line interface and the secondary Ethernet interface.
A 9600 Series IP Telephone initiates LLDP after receiving an LLDPDU message from an appropriate system. Once initiated, the telephones send an LLDPDU every 30 seconds with the following contents:
Table 13: LLDPDU Transmitted by 9600 Series SIP IP Telephones
Category | TLV Name (Type) | TLV Info String (Value) |
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|
|
Basic Mandatory | Chassis ID | IPADD of telephone, IANA Address Family |
|
| Numbers enumeration value for IPv4, or |
|
| subtype 5:Network address. |
|
| MAC address of the telephone. |
Basic Mandatory | Port ID | |
|
| 120 seconds. |
Basic Mandatory | ||
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| 1 of 3 |
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Issue 2 December 2007 101
