CANOGA PERKINS 2461 E1 Modem - Manual (Page 47)

EdgeAccess Universal Chassis System
5.4 Loopback and Bit Error Rate Testing
The Diagnostics Screen, as shown in Figure 31, can be accessed from both the stand alone and
rack mount modems. Diagnostic testing can be performed on the local modem and its secondary
redundant partner. Remote modems show the status of the diagnostic performed.
Figure 33. The Diagnostics Screen provides access to BERT and Loopback testing
From the Modem Main Menu, type "2" to access the Diagnostic screen. The Modem Diagnostics
Screen reports BERT status (Sync Status, Error Rate, Count, Sync Count, and Up Time), as well
as Loopback tests.
Active options are accessed by typing 1 through 4.
1. Loopback:
Use the space bar to toggle through the following loopback options:
• Local Local electrical interface looped back, AIS sent on the Fiber Optic
towards the remote modem
• Remote Loopback at the remote unit on the fiber optic side. Remote unit is
also sending AIS out the electrical interface
• Remote BERT Loopback at the remote unit on the fiber optic side. Remote unit is
also sending AIS out the electrical interface. Local unit sends a
QRSS pattern towards the remote unit and monitors the received
pattern. This pattern is sent from the LIU chip and uses the full E1
or E1 bandwidth in unframed mode, AMI coding. The local unit is
also sending AIS out the electrical interface
• Local BI
Local electrical interface looped back. Local signals looped back on
the fiber side as well. In a Bi-Directional Loopback (Local BI and
Remote BI), data is looped back in both directions, assuring a stricter
standard of error checking.
2461 Modem User Manual 5-3