Selecting Test Features

Using Receive Overhead Monitor

If BYTE NAMES is chosen, the labels for the bytes are displayed.

STS-1# 1,2,3

overhead

4 If POH (Path Overhead) is chosen, choose the source of the overhead, SPE or VTSPE.

J1 and J2 bytes can be monitored under Path Overhead or Trace Messages

5 If TRACE MESSAGES is chosen, you can monitor a data message to verify portions of the network.

If the 16 byte CRC7 message structure is detected, the 15 characters within the message are displayed.

If the CRC7 structure is not detected in J1, the 64 byte message format is assumed and displayed.

If the CRC7 structure is not detected for J0 or J2, all 16 bytes are displayed.

6

If LABELS is chosen, the S1 sync status, STS path label (C2) and the

 

VT Path label (V5) are monitored.

7

If APS MESSAGES is chosen, choose the TOPOLOGY, LINEAR (GR-

 

253) or RING (GR-1230). The K1 and K2 bits are monitored.

TIP:

If any abnormal behavior is observed on a particular path or section

 

overhead byte, or an associated group of bytes (3XA1,3XA2; D1 - D3), the

 

RECEIVE

TEST FUNCTION

display of OVERHEAD CAPTURE can be

 

used to "Zoom" in on the suspect byte or bytes on a frame by frame basis.

 

See "Using Receive Overhead Capture " page 29.

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Image 35
HP BER 718 37718A manual Display of Overhead Capture can be