DASS II Voice I (EMEAAP only) Programming

Program DASS II Local Exchange Lines

Because the Universal NSU with E1 card can be used with both DASS II local exchange lines and DPNSS private networks, the customer data must specify which protocol the circuits are being used with.

To program DASS II local exchange lines, you must complete the following forms:

1. System Options
   Define Route Optimisation, Maximum Conference parameters, and Last Number Redial.

2. NSU Configuration form
   Define the programmed type

3. Trunk Attributes

4. Digital Link Descriptors

5. MSDN-DPNSS-DASSII Trunk Circuit Descriptors

6. ARS Routes

7. ARS Route Lists

8. ARS Route Plans

9. Digital Links

10. Trunk Circuits Descriptors

11. Digital Trunks

12. Trunk Groups

13. Network Synchronization

14. Interconnect Restriction Table.

Maintenance and Fault-finding

Directed and background diagnostics are an integral part of the DASS II feature. The diagnostics, along with the reports and logs they produce, allow the maintenance engineer to isolate faults on the CEPT Formatter card and its associated software.

Network Synchronization

Network Synchronization Source

A network synchronization source is a clock that is available to all nodes in a network as a common timing source. The nodes in the network can be synchronized with each other only if they have this common timing source. Serious losses of data can occur if the nodes involved in a call are not synchronized.

In the case of a DASS II system, the network is the Integrated Services Digital Network and the nodes are the systems attached to the network via a digital local exchange line. Each node can be a stand-alone system or it can be the "gateway" system between ISDN and a private DPNSS network.

For a private network connected to the local exchange via a DASS II link, the first source should always be the timing signals transmitted by the local exchange. This ensures that the network is always synchronized to the local exchange and ISDN.

To select a synchronization source, type Netsync setsource <source>, where <source> can be the number of one of the sources listed on the Network Synchronization form. Refer to Customer Data Entry for details of this form.
FREERUN, that is, the active Clock/Tone Generator on the node; AUTO, that is, the best source available in the system, as defined by the order of the entries on the Network Synchronization form.

The system response to the Netsync setsource command consists of a message on the maintenance terminal and an appropriate system action.

Network Synchronization State

Type Netsync stat to check the synchronization status of a system connected to a DASS II network.

The system response to this command is either:

NETSYNC FAILED: No response from NETSYNC process

or a table of synchronization sources in the form:

In this table:

No. Is the source number from the Network Synchronization Data Entry form.

Source Location is the location of the CEPT hybrid which is providing the synchronization signal. The numbers shown in the table refer to the cabinet, shelf, slot and hybrid in that order.

Source Status for CTG shows the status of each synchronization source from the point of view of the Clock/Tone Generator at the specified location.

The status can be:

SYNC SOURCE if the active Plane Clock/Tone Generator is its own synchronization source.

AVAILABLE if there is an incoming signal at the CEPT hybrid and the clock can be extracted from this signal. AVAILABLE is not an indication that the source is stable or that the system will choose this source if set to AUTO. An unstable source continues to be AVAILABLE.

NOT AVAILABLE if the CEPT hybrid is not available as a synchronizing source, possibly because of loopback testing.

UNKNOWN if the Clock/Tone Generator did not reply to the request for status information, or if the hybrid did not reply to the NETSYNC SETSOURCE commands. The node that is providing the source may be out of service if the status is UNKNOWN.

• Note: The NETSYNC SETSOURCE (NET SET) command is meaningless on a system which is not part of a network or which has no synchronizing sources listed on the Network Synchronization form.

Obtaining a Summary of Synchronizing Source Activity

You can obtain a report of the active planes synchronizing source for any number of hours during the past 24 hours. The report contains statistics about the behavior of the active Clock/Tone generator for the period under consideration. To obtain the summary report, type netsync summary <shelf number> last <number of hours>, where <number of hours> is between 0 and 24 inclusive.

Type 0 hours if you want a report for the period from the start of the last hour. For example, if you request a LAST 0 report at 16:25, the report will include statistics for the 25 minute period from 16:00.
You can omit the "LAST number of hours" parameter, in which case the system produces a report for the current hour.

The system response to the request is either the message: NETSYNC FAILED: No response from NETSYNC process

or a report in the following format:

In this report:

Time Start and End define the time interval during which the information on a line applies. Each line covers the events for a complete hour unless:

• The system has switched on during the hour;

• An activity switch has taken place during the hour. ACT CLK indicates the activity state of the Clock/Tone Generator specified in the command. ACT in this column indicates that the Clock/Tone Generator was active for the whole of the monitored period; a blank in this column indicates that the Clock/Tone Generator was inactive for the whole of the period.

The Single Hits column indicates the number of times that the phase of the synchronizing source has shifted away from the normal and returned to normal within 100 ms.

The Phase Shifts column indicates the number of times that the phase of the synchronizing source has shifted away from the normal and stayed at the new value for longer than a byte, that is eight bits.

Control Range % shows the accuracy with which the Clock/Tone Generator has synchronized to the synchronizing source. A reading of 100% indicates that the Clock/Tone Generator has maintained synchronization with the source; a low reading (of the order of 40%) indicates that either the synchronizing source or the Clock/Tone Generator is unstable.

Sync Sources Used lists the synchronization sources used during the period covered by the line of the report. If the line is for the current hour and includes more than one entry, the most recently used source is on the left. For example, the entry for the period 16:00 to 16:33 lists four sources, the most recent source is FREERUN, followed by source 1, source 2 and source 3 in that order. If the line is not for the current hour, the synchronization sources used are listed in a preset order, not necessarily the order in which they were used.

The entry in the column can be:

• LOCKACT if the inactive Clock/Tone Generator is locked to the active Clock/Tone Generator. This happens when:

• The synchronizing source is MASTER or FREERUN, that is, the active Clock/Tone Generator.

• The source used by the active Clock/Tone Generator is not available to the inactive Clock/Tone Generator.

• The inactive Clock/Tone Generator cannot synchronize to the sourced used by the active Clock/Tone Generator.

• FREERUN if the active Clock/Tone Generator is not using any of the synchronizing sources specified on the Network Synchronization Data Entry form.

• A number in the range 1 to 8 to indicate one of the sources, First, Second, Third and so on, from the Network Synchronization Data Entry form.

Network Synchronization Alarms

The system raises a minor alarm if the active Clock/Tone Generator is not synchronized with the first synchronizing source listed on the Network Synchronization Data Entry form.

The SHOW STATUS report includes a category NETWORK SYNC SOURCE for network synchronization. The report refers to the operational status of the system Clock/Tone Generators and shows Total in System values of 1 for a non-redundant system and 2 for a redundant system. The system raises a minor alarm in this category if the active Clock/Tone Generator cannot communicate with the inactive Clock/Tone Generator to verify its status.

Network Synchronization Maintenance Logs

The system adds an entry to the maintenance log whenever the synchronization source for either the active or inactive Clock/Tone Generator changes.

Network Synchronization Reports

The network synchronization report consists of three lines of information which the system inserts in the maintenance log when the synchronization source changes. The report is in the form:

<date and time> MAINTENANCE <plane>/Active <alarm type> # <report number>
Change in synchronization source from <source x> to <source y>

OR

Change in synchronization selection mode to auto
Justification: <justification>

In the report:

• DASS II Voice I (EMEAAP only) Conditions

• DASS II Voice I (EMEAAP only) Description

• DASS II Voice I (EMEAAP only) Installation