Bridging
4-76 SONET Port Configuration
To set the operational mode of the SONET port via the SONET/SDH
ConÞguration window:
1. Click in the radio box adjacent to the appropriate selection, SONET or SDH,
to choose the data transmission standard to be used by the interface.
2. Click on Apply to set your change at the interface, or Cancel to exit the
SONET/SDH Configuration window without applying any changes.
SONET/SDH Statistics Window
SONET/SDH statistics are available for each FE100-Sx or APIM-2x port interface
module installed in your device. The same statistics apply whether you have
conÞgured the interface to operate according to SONET or SDH transmission
standards.
The FE100-Sx and the APIM-2x port interface modules are SONET
path-terminating equipment (PTE). They act as an endpoint of an end-to-end
connection between themselves and another similar port interface module. As
endpoints, they are capable of generating and receiving the Path Overhead
information contained within the SPE (Synchronous Payload Envelope) of the
base-level SONET or SDH signals. Simply put, overhead is the extra bits in the
digital stream that relay information besides trafÞc signals.
The Path Overhead provides for end-to-end performance monitoring of the link,
the signal label (the content of the SPE, including status of mapped payloads), the
pathÕs current status, and path trace capabilities.
The SONET/SDH Statistics window enables you to view some of the error
information contained within the Path Overhead that your FE100-Sx or APIM-2x
is receiving from the remote endpoint.
The window will inform you whether there have been speciÞc defects
experienced on the SONET link, and if the network has experienced any
signiÞcant unavailability time as a result.
With a SONET link, there are three levels of error conditionsÑanomalies, defects,
and failures.
¥ Anomalies are small discrepancies between a desired and actual characteristic
of an item, which when occurring singly will not interrupt the ability of the
SONET network elements to perform their required functions.
¥ Defects indicate that anomalies have reached a level where the ability of the
SONET network elements to perform their required functions has been
interrupted. Defects are used in performance monitoring and in determining
the faultÕs cause, and have impact on consequent actions on the network.
¥ Failures indicate that a network element has been unable to perform its
required functions beyond a maximum time allocated to a given error
condition.