3com S7906E 설치 설명서

 

1-4 

Responding to Loopback 
Control OAMPDUs 

Available (if both sides operate 
in active OAM mode)  

Available 

 

z 

OAM connections can be initiated only by OAM entities operating in active OAM mode, while those 

operating in passive mode wait and respond to the connection requests sent by their peers.  

z 

No OAM connection can be established between OAM entities operating in passive OAM mode.  

 

After an Ethernet OAM connection is established, the Ethernet OAM entities on both sides exchange 

Information OAMPDUs periodically to keep the Ethernet OAM connection valid. If an Ethernet OAM 

entity receives no Information OAMPDU for five seconds, the Ethernet OAM connection is 

disconnected.  

 

The interval to send Information OAMPDUs is determined by a timer. Up to ten Information OAMPDUs 

can be sent in a second. 

 

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. Upon detecting a link error event 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 in time. 

 describes the 

link events. 

Table 1-4 Ethernet OAM link error events 

Errored symbol event 

An errored symbol event occurs when the 
number of detected symbol errors over a specific 
detection interval exceeds the predefined 
threshold. 

Errored frame event 

An errored frame event occurs when the number 
of detected error frames over a specific interval 
exceeds the predefined threshold.  

Errored frame period event 

An errored frame period event occurs if the 
number of frame errors in specific number of 
received frames exceeds the predefined 
threshold.