Zhone Technologies IMACS Network Device - Manual (Page 111)

Zhone Technologies, Inc. IMACS Product Book, Version 4
March 2001 Page 107
Toward WAN 2
Voice
Without
Singaling
Voice
With
Singaling
Single Data
DS0
(64Kbps)
Super-rate
Data
(Nx64Kbp
s)
Set Transmit ABCD Signaling Bits N/A Yes N/A N/A
Monitor Status of Transmit ABCD
Signaling Bits N/A Yes N/A N/A
Monitor Status of Receive ABCD
Signaling Bits N/A Yes N/A N/A
Benefits of Built-In Diagnostics
The real power of the integral diagnostics of the IMACS can be fully appreciated when the individual diagnostic
tools are applied to everyday troubleshooting such as the one illustrated in the following example.
The environment shown in Figure 44 consists of two IMACS’ connected by a T1 line. These are referred to as the
Local IMACS and the Remote IMACS respectively. At the local IMACS, the DTE equipment is a co-located
device providing a 56 Kbps V.35 interface that is connected to a V.35 HSU port. At the Remote IMACS, an OCU-
DP card that interfaces to the 4-wire DDS tail-circuit extends the 56 Kbps to a third location. Consequently, the
Remote IMACS is equipped with an OCU-DP card that interfaces to the 4-wire DDS tail-circuit. At the third
location, the DDS circuit terminates in a generic, third party DSU/CSU that in turn provides a 56 Kbps V.35
interface to the remote DTE device.
The system operator can use the diagnostic tool kit to systematically troubleshoot the problem on an end-to-end
basis and to identify the faulty sub-system, even if it is external to the IMACS. One way to systematically
troubleshoot the problem is illustrated in Figure 44. While there are many other approaches, in general, the
procedure to follow is to combine loop backs that are generated either through software commands or via industry-
standard loop-up codes with Bit Error Rate Tests (BERTs) for data circuits, or test tones for voice circuits. In the
IMACS, all of those tools are available as integral features of the system and of the various cards. Each test
determines if a specific sub-system is operating properly. In our example, after each test, the sub-systems that are
shown to be functioning properly are shaded in gray.
In Figure 44, the local HSU card is put in Local loop back and a BERT test is run from the DTE. If successful, in
Figure 44, diagnostics-figure 3, the loop back sequence is advanced by putting the T1 link of the Local IMACS in
Local loop back and running BERT test again. This also tests the cross-connect element of the local IMACS if there
is one present. In Figure 44XX, diagnostics-figure 4, the T1 link of the remote IMACS is configured in Line Loop
back. Alternatively, a loop up code can be sent from the local IMACS to put the T1 link of the remote IMACS in
Line loop back. This process is repeated until the remote DTE is put in network loop back and tested as shown
Figure 44, diagnostics-figure 8.