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HP OMNIBER 718 HP 37718A User Manual

Page 35

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25

Selecting Test Features

Using Receive Overhead Monitor

If BYTE NAMES is chosen, the labels for the

overhead

bytes are displayed.

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,

(GR-

253) or

(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

display of

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.

STS-1# 1,2,3

LINEAR

RING

RECEIVE

TEST FUNCTION

OVERHEAD CAPTURE