Zhone Technologies 900 - Manual (Page 96)

3-8 IMACS System Release 5.1.6 Data Cards
Model No. Running Head OCU-DP Card User Screens and Settings OCU-DP Card
LB
The OCU-DP card supports three Loopback options that test on the card itself. The dte option
loops the 4-wire analog interface of the OCU-DP port towards the attached CSU/DSU. It is
used to test the local cabling and the analog drivers in the OCU-DP card (see Figure 3-3).
The net-a (Network A) option loops the 4-wire OCU-DP interface towards the network. Use
it to test all of the OCU-DP card circuitry, the system common equipment, the WAN link card,
the remote equipment and the WAN line between the two sites (see Figure 3-4).
Note: There are various types of test sets that can be used to generate loopbacks in the field.
When a test set is initiated for an OCU-DP card an “l” status should be present on
the port of the OCU-DP to indicate a loopback. If not, simply perform a “refresh”
operation to update the screen.
The net-d (Network D) option puts a loopback towards the network at the point where the
OCU-DP card interfaces with the system bus. It separates the OCU-DP card circuitry from the
system common equipment, WAN card, remote equipment, and WAN line between the two
sites (see Figure 3-5).
Figure 3-3. OCU Local Loopback (dte option)
OCU-DP Card OCU-DP Card
CSU/DSU CSU/DSU Local
DTE
Remote
DTE
Carrier's DDS
Network
Local System
Local Site Remote Site
Remote System