Zhone Technologies IMACS-200 manual Benefits of Built-In Diagnostics

System Testing and Diagnostics Benefits of Built-In Diagnostics

	Voice	Voice with	Single Data	Super-rate
	without		DS0	Data
		Signaling
	Signaling		(64 Kbps)	(N x 64 Kbps)
Signaling Manipulation
Toward WAN 1
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
Toward WAN 2
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

14.5 Benefits of Built-In Diagnostics

The real power of the integral diagnostics of the Integrated Access System 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 14-1consists of two integrated access devices connected by a T1 line. These are referred to as the Local IAD and the Remote IAD respectively. At the local IAD, the DTE equipment is a co-located device providing a 56 Kpbs V.35 interface that is connected to a V.35 HSU port. At the Remote IAD, an OCU-DP port that interfaces to the 4-wire DDS tail-circuit extends the 56 Kbps to a third location. Consequently, the Remote IAD is equipped with an OCU-DP port that interfaces to the 4-wire DDS tail-circuit. At the third location, the DDS circuit terminates in a generic, third-party DSU/CSU which 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 Integrated Access System. One way to systematically troubleshoot the problem is illustrated in Figure 14-1.While there are many other approaches, in general, the procedure to follow is to combine loopbacks 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 Integrated Access System, all of those tools are available as integral features of the system and of the various ports. 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 14-1,the local HSU port is put in Local loopback and a BERT test is run from the DTE. If successful, in Figure 14-1,diagnostics-3 the loopback sequence is advanced by putting the T1 link of the Local Integrated Access System in Local loopback and running BERT test again. This also tests the cross-connect element of the local Integrated Access System if there is one present.

Diagnostics 14-5