Allied Telesis AT-S70 - Manual (Page 89)

AT-S70 Management Software User’s Guide
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Table 3 lists the OAM Active and OAM Passive mode behaviors.
OAMPDU Types
Two Ethernet ports use OAMPDU to exchange the OAM protocol. The
OAMPDUs use a specific multicast destination address and EtherType.
Most of the OAMPDU types are used to define a set of standard type-
length-value (TLV) encoding of attributes within the type. The OAMPDU
types are described below:
ˆ Information OAMPDUs – Information OAMPDUs are used for
discovery; they are variable-length OAMPDUs. There are three TLVs
for Information PDUs: Local Information, Remote Information, and
Organizational Specific. Local and Remote Information is used in the
discovery process. The Organizational Specific Information TLV is
used for vendor extensions.
ˆ Event OAMPDUs – Event OAMPDUs are used for link monitoring,
they are variable-length OAMPDUs. The data field in this event
OAMPDU contains a data field of one or more link event TLVs.
ˆ Loopback Control OAMPDUs – Loopback Control OAMPDUs are
used to provide the loopback command.
ˆ Variable Request/Response OAMPDUs – The Variable Request/
Response OAMPDUs accessible through OAM must be in the
Ethernet branch of the management information based (MIB) tree. For
more information, refer to “MIB Variable Retrieval and Extensions” on
page 90.
Table 3. OAM Active and Passive Mode Behaviors
Capability Active Passive
Initiates OAM Discovery process Yes No
Reacts to OAM Discovery process initiation Yes Yes
Required to send Information OAMPDUs Yes Yes
Permitted to send Event Notification OAMPDUs Yes Yes
Permitted to send Variable Request OAMPDUs Yes No
Permitted to send Variable Response OAMPDUs Yes* Yes
Permitted to send Loopback Control OAMPDUs Yes No
Reacts to Loopback Control OAMPDUs Yes* Yes
Permitted to send Organization Specific
OAMPDUs Yes Yes
* Requires the peer station to be in Active mode.