Protocols And Standards - HP 5900 Series Configuration Manual

Ethernet OAM link events
Errored frame event
Errored frame period event
Errored frame seconds event
Remote fault detection
Information OAMPDUs are exchanged periodically among Ethernet OAM entities across established
OAM connections. In a network where traffic is interrupted due to device failures or unavailability, the
flag field defined in Information OAMPDUs allows an Ethernet OAM entity to send error information (any
critical link event type shown in
status and troubleshoot problems promptly.
Table 4 Critical link events
Type
Link Fault
Dying Gasp
Critical Event
The switch is able to receive Information OAMPDUs carrying the critical link events listed in
The switch is able to send Information OAMPDUs carrying Link Fault events.
The switch is able to send Information OAMPDUs carrying Dying Gasp events when the switch is
rebooted or relevant ports are manually shut down. Physical IRF ports, however, are unable to send this
type of OAMPDUs.
The switch is unable to send Information OAMPDUs carrying Critical Events.
Remote loopback
Remote loopback is available only after the Ethernet OAM connection is established. With remote
loopback enabled, the Ethernet OAM entity in active mode sends non-OAMPDUs to its peer. After
receiving these frames, the peer does not forward them according to their destination addresses. Instead,
it returns them to the sender along the original path.
Remote loopback enables you to check the link status and locate link failures. Performing remote
loopback periodically helps to detect network faults promptly. Furthermore, performing remote loopback
by network segments helps to locate network faults.

Protocols and standards

IEEE 802.3ah, Carrier Sense Multiple Access with Collision Detection (CSMA/CD) Access Method and
Physical Layer Specifications
Description
An errored frame event occurs when the number of detected error frames in
the detection window (specified detection interval) exceeds the predefined
threshold.
An errored frame period event occurs when the number of frame errors in
the detection window (specified number of received frames) exceeds the
predefined threshold.
An errored frame seconds event occurs when the number of errored frame
seconds (the second in which an errored frame appears is called an
"errored frame second") detected on a port in the detection window
(specified detection interval) reaches the predefined threshold.
Table 4) to its peer. You can use the log information to track ongoing link
Description
Peer link signal is lost.
An unexpected fault, such as power failure,
occurred.
An undetermined critical event happened.
OAMPDU transmission frequencies
Once per second.
Non-stop.
Non-stop.
3
Table 4.