P-870HN-51D User’s Guide
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CHAPTER 23
Diagnostic
23.1 Overview
The Diagnostic screens display information to help you identify problems with the
P-870HN-51D.
The route between a CO VDSL switch and one of its CPE may go through switches
owned by independent organizations. A connectivity fault point generally takes
time to discover and impacts subscriber’s network access. In order to eliminate
the management and maintenance efforts, IEEE 802.1ag is a Connectivity Fault
Management (CFM) specification which allows network administrators to identify
and manage connection faults. Through discovery and verification of the path,
CFM can detect, analyze and isolate connectivity faults in bridged LANs.
23.1.1 What You Can Do in this Chapter
•The General screen lets you ping an IP address or trace the route packets take
to a host (Section 23.3 on page 236).
•The 802.1ag screen lets you perform CFM actions (Section 23.4 on page 237).
23.2 What You Need to Know
The following terms and concepts may help as you read through this chapter.
How CFM Works
A Maintenance Association (MA) defines a VLAN and associated Maintenance End
Point (MEP) ports on the device under a Maintenance Domain (MD) level. An MEP
port has the ability to send Connectivity Check Messages (CCMs) and get other
MEP ports information from neighbor devices’ CCMs within an MA.
CFM provides two tests to discover connectivity faults.
