TP-Link T2600G-28TS User Manual page 130

Information OAMPDU: Information OAMPDU is used for discovery. It transmits the state
information of an OAM entity (including local, remote, and organization-specific information)
to another OAM entity, and maintains OAM connection.
Event Notification OAMPDU: Event Notification OAMPDU is used for link monitoring. It is sent
as an alarm when a failure occurs to the link connecting the local OAM entity and a remote
OAM entity.
Loopback Control OAMPDU: Loopback Control OAMPDU is used to control the remote client's
OAM remote loopback state. Its Data field consists of a remote loopback command to enable
or disable the OAM remote loopback, so that the local client can enable/disable loopback on
the remote OAM entity.
OAM Functions

As defined by IEEE 802.3
Link Monitoring, Remote Failure Indication, and Remote Loopback.
Discovery
Discovery is the first phase of Ethernet OAM. During this phase, an OAM entity discovers other
OAM entities and establishes connections using Information OAMPDUs.
As for OAM connection, an OAM entity can operate in two modes: active and passive. Only the
active OAM entity can initiate an OAM connection process. The passive OAM entity waits and
responds to OAM connection establishment requests. Interconnected OAM entities notify the peer
of their OAM configuration information and the OAM capabilities of the local nodes to support
OAM by exchanging Information OAMPDUs, and then determine if OAM connections can be
established. Only when the settings concerning Loopback, link detecting, and link event of the
both side match can an OAM connection be established.
The difference between active OAM mode and passive OAM mode is shown as follows.
Item
Initiating OAM Discovery
Responding to OAM Discovery
Transmitting Information OAMPDUs
Transmitting
OAMPDUs
Transmitting Information OAMPDUs
with the Data/Pad field being empty
, Ethernet in the First Mile., OAM functions include Discovery,
Clause 57
Figure 8-2 OAM Discovery
Event Notification
Active OAM mode
Available
Available
Available
Available
Available
118
Passive OAM mode
Unavailable
Available
Available
Available
Available