RAD Data comm HCD-E1

HCD-E1 Installation & Operation Manual Chapter 5 - Troubleshooting and Diagnostics

01/01/01 08:15 Performance Diagnostics Data 5-13

General HCD-E1 has two capabilities for collection of performance statistics: E1 and

HDSL performance monitoring capability.

This section first describes the principles and parameters of the E1 and

HDSL performance monitoring and then explains how to display

performance data from the HCD-E1 front panel. For information on

displaying the performance data from the control terminal, see Chapter 4.

Performance

Monitoring

This section describes the performance evaluation and monitoring functions

provided by HCD-E1 with respect to the user's traffic (on the E1 link

between the DTE and the user’s port). The functions actually available

depend on the use of the CRC-4 function: whether it is enabled or disabled.

Below are listed performance monitoring parameters with the CRC-4

function enabled and disabled, followed by a summary table (Table 5-2)

listing the displays of all these parameters on the HCD-E1 front panel in the

order of their appearance, accompanied by a short description and ranges

available.

E1 Performance Monitoring with CRC-4 Function Enabled

When the CRC-4 function is enabled, you are able to monitor the

end-to-end data transmission performance. HCD-E1 derives information

about errors from the E1 data payload by performing a cyclic redundancy

check (CRC), and transmits the resulting CRC checksum in addition to the

raw data bits.

The receiving end recalculates the checksum and compares the results with

the received checksum: any difference between the two checksums

indicates that the current data block being evaluated contains bit errors.

When the CRC-4 function is enabled, HCD-E1 stores E1 line statistics for the

E1 port. This permits real-time monitoring of E1 data transmission

performance.

The performance monitoring parameters are listed below:

• Current CRC-4 error events (ERROR CRC)

A CRC-4 error event is any multiframe containing a CRC error and/or

OOF event. The number of CRC events in the current second is collected

in a current CRC error events register.

• Current average CRC-4 errors (AV ERR CRC)

The average number of CRC events per second. The average is updated

every second.

Note

You can display the register contents at any time. When the CRC error events

are displayed on the front-panel LCD, you can reset the register by pressing

ENTER.