HP A5830 series Configuration Manual page 13

Ethernet OAM connection establishment
Ethernet OAM connection is the basis of all 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. You can establish an Ethernet OAM
connection between entities that have matching Loopback, link detecting, and link event settings. After
you establish an Ethernet OAM connection, 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
Initiating OAM Discovery
Responding to OAM Discovery
Transmitting Information
OAMPDUs
Transmitting Event Notification
OAMPDUs
Transmitting Information
OAMPDUs without any TLV
Transmitting Loopback Control
OAMPDUs
Responding to Loopback Control
OAMPDUs
NOTE:
Only OAM entities operating in active OAM mode can initiate OAM connections. OAM entities
•
operating in passive mode wait and respond to the connection requests sent by their peers.
No OAM connection can be established between OAM entities operating in passive OAM mode.
•
After you establish an Ethernet OAM connection, the Ethernet OAM entities on both sides exchange
Information OAMPDUs at a specified interval (handshake packet transmission interval) to check whether
the Ethernet OAM connection is normal. If an Ethernet OAM entity receives no Information OAMPDU
within the Ethernet OAM connection timeout time, the Ethernet OAM connection is considered
disconnected.
Link monitoring
Error detection in an Ethernet is difficult, especially when the physical connection in the network is not
disconnected but network performance is degrading gradually. Link monitoring is used to detect and
indicate link faults in various environments. Ethernet OAM implements link monitoring through the
exchange of Event Notification OAMPDUs. When detecting one of the link error events listed in
the local OAM entity sends an Event Notification OAMPDU to notify the remote OAM entity. With the
log information, network administrators can keep track of network status promptly.
Active Ethernet OAM mode
Available
Available
Available
Available
Available
Available
Available—if both sides operate
in active OAM mode
13
Passive Ethernet OAM mode
Unavailable
Available
Available
Available
Available
Unavailable
Available
7,
Table