H3C S5120-EI Series - How Ethernet OAM Works

5
Field Descri
p
tion
Subtype
The specific protocol being encapsulated in the Ethernet OAMPDU
The value is 0x03.
Flags Status information of an Ethernet OAM entity
Code Type of the Ethernet OAMPDU
NOTE:
Throughout this document, a port with Ethernet OAM enabled is an Ethernet OAM entity or an OAM
entity.
Table 5 Functions of different types of OAMPDUs
OAMPDU t
yp
e 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 basis 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 determine whether Ethernet OAM connections can be
established, by exchanging Information OAMPDUs to notify the peer of their OAM configuration
information and the OAM capabilities of the local nodes. An Ethernet OAM connection can be
established between entities that have matching Loopback, link detecting, and link event settings. After
an Ethernet OAM connection is established, Ethernet OAM takes effect on both sides.
For Ethernet OAM connection establishment, a device can operate in active Ethernet OAM mode or
passive Ethernet OAM mode, but a switch role will be somewhat different depending on the mode.
Table 6 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