2-3
Table 2-2
Functions of different types of OAMPDUs
OAMPDU type
Function
Information
OAMPDU
Used for transmitting state information of an Ethernet OAM entity (including the
information about the local device and remote devices, and customized information) to
the remote Ethernet OAM entity and maintaining OAM connections
Event Notification
OAMPDU
Used by link monitoring to notify the remote OAM entity when it detects problems on the
link in between.
Loopback Control
OAMPDU
Used for remote loopback control. By inserting the information used to enable/disable
loopback to a loopback control OAMPDU, you can enable/disable loopback on a remote
OAM entity.
How Ethernet OAM Works
This section describes the working procedures of Ethernet OAM.
Ethernet OAM connection establishment
Ethernet OAM connection is the base of all the other Ethernet OAM functions. OAM connection
establishment is also known as the Discovery phase, where an Ethernet OAM entity discovers remote
OAM entities and establishes sessions with them.
In this phase, interconnected OAM entities notify the peer of their OAM configuration information and
the OAM capabilities of the local nodes by exchanging Information OAMPDUs and determine whether
Ethernet OAM connections can be established. An Ethernet OAM connection can be established only
when the settings concerning Loopback, link detecting, and link event of the both sides match. After an
Ethernet OAM connection is established, Ethernet OAM takes effect on it.
As for Ethernet OAM connection establishment, a device can operate in active Ethernet OAM mode or
compares active Ethernet OAM mode with passive Ethernet
OAM mode.
Table 2-3
Active Ethernet OAM mode and passive Ethernet OAM mode
Item
Active Ethernet OAM mode
Passive Ethernet OAM
mode
Initiating OAM Discovery
Available
Unavailable
Responding to OAM Discovery
Available
Available
Transmitting Information OAMPDUs
Available
Available
Transmitting Event Notification OAMPDUs
Available
Available
Transmitting Information OAMPDUs with the
Data/Pad field being empty
Available Available
Transmitting Loopback Control OAMPDUs
Available
Unavailable