3Com S7906E - Switch, Configuration Manual

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1-3
Table 1-2 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
passive Ethernet OAM mode. Table 1-3 compares active Ethernet OAM mode with passive Ethernet
OAM mode.
Table 1-3 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