NTP
NTP 297-1001-107 PAGE 6
PREL., ISSUE 01D01
June 22, 1978
4. INTERNAL MAINTENANCE FACILITIES
MAINTENANCE AND ADMINISTRATIVE POSITION (MAP)
4.01 The Maintenance and Administrative Position (MAP) is the
primary interface between the Telco personnel and the DMS system.
System tests, data interrogation and modification, and trouble
analysis functions are provided. The MAP is designed to operate
as a single entity for small office applications as well as a
large system interface where several units can operate
concurrently. It can be used in any of the maintenance and
administrative environments in DMS. These include:
- General maintenance;
- Network Management;
- Operational Measurements;
- Service Analysis;
- Trunk Test;
- Data Modification;
- Line Test.
The MAP has three basic components, namely: the visual
display unit (VDU), the communications module, and the position
furniture.
4.02 The VDU is composed of a cathode ray tube display device
and a typewriter-type keyboard for information entry. Using the
VDU, and a telescoping process, Telco personnel can examine the
system on several levels of detail. At each level of detail a
menu of commands is displayed from which action requests can be
selected. The result of a request is then displayed on the VDU.
A printer associated with the VDU can be operated in parallel
with it to provide a permanent copy of the display. Other
printers or teletypes (TTY) can also be used for data entry and
retrieval.
4.03 The communications module is based on a LOGIC 10 (Local
use) or LOGIC 20 (Toll use) key telephone set. It provides the
maintenance personnel with telephone links both within and out of
the office and access to the office talk line. An automatic
dialer, a hands-free unit and a headset may also be provided. A
jack field on the position furniture is part of the trunk test
facility. One jack can be used for Telco determined purposes
such as connecting to a VF patch bay. The others connect to jack
DMS 100 FAMILY
MAINTENANCE AND ADMINISTRATION TOOLS DESCRIPTION
(c) NORTHERN TELECOM LIMITED, 1978
NTP 297-1001-107 PAGE 7
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ended trunks through which access can be gained to any line or
trunk in the office. Portable test equipment can be plugged into
the jacks to perform various tests such as Echo Return Loss or
Singing Point measurements.
4.04 The position furniture consists of table and shelf units
which can be assembled in various configurations to provide work
space and document storage for administrative or maintenance
functions, and to mount the VDU and communications module
components.
4.05 For more information on the MAP and it's use, refer to NTP
297-1001-110 DMS 100 Family Maintenance and Administration
Position (MAP). The format, content, and classification of
output messages available to the MAP user are described in NTP
297-1001-510 DMS 100 Family Output Commands Description. Input
commands are dependant on the Maintenance Subsystem entered.
They are described in the series of NTP's 297-1001-511 to
297-1001-518 inclusive, entitled (Maintenance Subsystem Name) Man
Machine Interface Description.
PERFORMANCE ORIENTED PRACTICE (POP)
4.06 The Performance Oriented Practice (POP) is a system of
documentation designed to support the Telco in the operation and
maintenance of the DMS 100 Family. The information it contains
is of sufficient depth to support the inexperienced user but
structured to permit the experienced user to bypass detailed
instructions if the task can be performed from memory.
4.07 POP is task oriented rather than hardware or software
oriented. It is accessed when a stimulus such as an alarm or
trouble report is received. The instructions in POP then guide
the user in performing the activities required to achieve the
objective, i.e. retiring the alarm or clearing the trouble.
Crossing hardware or software boundaries within or between
subsystems does not generate a new task as long as the stimulus
and objective remain the same.
4.08 The POP is packaged as an NTP. The Order procedures are
separate from the Maintenance procedures. The maintenance POP is
packaged as NTP 297-1001-500. For a detailed description of POP
and it's use, refer to NTP 297-1001-040.
DMS 100 FAMILY
MAINTENANCE AND ADMINISTRATION TOOLS DESCRIPTION
(c) NORTHERN TELECOM LIMITED, 1978
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FAULT ISOLATION AND RECOVERY
4.09 Fault isolation and recovery functions are performed by
the maintenance system. Faults are detected by hardware such as
parity check circuitry or by software checks such as checksums on
messages. Isolation and recovery software locates the source of
the fault, alerts office personnel and configures suspected
equipment out of service to reduce the chance of affecting call
processing. Diagnostics determine the cause of the fault.
4.10 The maintenance system is divided into ten subsystems.
Each subsystem can diagnose faults only within it's range of
responsibility. A diagnostic within a subsystem can be initiated
by the same or another subsystem, the alarm system, or by
maintenance personnel on a scheduled, system demand, or manual
request basis.
4.11 In response to a diagnostic action the maintenance system
sends a report to the maintenance terminal. There are four types
of report, namely: error, diagnostic result, action taken, and
status.
4.12 With the MAP facilities office personnel can use
telescoping techniques to obtain ever-increasing detail about
system operation until a fault is isolated to one or more
replacable components. Defective components are identified in a
list, and in order of most probably defective component,
displayed on the VDU or teleprinter.
4.13 Details of the DMS Maintenance System can be found in NTP
297-1001-106 DMS 100 Family Maintenance System Description.
SOFTWARE MAINTENANCE
4.14 The correct operation of the DMS 100 family switching
systems is dependent upon the integrity of the software system.
To ensure this integrity, hardware and software mechanisms are
provided to continually verify its sanity. They include data
table indexing range checks, audits of software structures, and a
sanity timer which guards against software or micro-program loop
errors not otherwise detectable.
DMS 100 FAMILY
MAINTENANCE AND ADMINISTRATION TOOLS DESCRIPTION
(c) NORTHERN TELECOM LIMITED, 1978
NTP 297-1001-107 PAGE 9
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BOOTSTRAP LOADER
4.15 Bootstrapping is the process of a Central Control
autonomously loading it's Program Store (PS) and Data Store (DS)
from a bootstrap input device, eg. a Magnetic Tape Unit (MTU).
The bootstrap loader is implemented in microcode (firmware)
permanently located in the Read Only Memory (ROM) card of the
CPU. Bootstrapping a DMS office can occur in one of three modes
as follows:
a) Dead Office mode
b) Active Controlled mode
c) Autoload mode
All 3 modes share the same set of firmware.
4.16 Dead Office mode is used to load a nonfunctioning office.
Telco personnel activate the loader by means of manual control
switches located on the CPU, eg. the thumbwheel, DACT, and RESET.
Progress reports identifying stages of initialization, error
codes, load completion, etc. are made via the 2-digit display
also located on the CPU.
4.17 The Active Controlled mode is used in a normally
functioning office. The Active Central Control (CC) can process
calls and, at the same time, control the bootstrap loader in the
offline CC. The controlling and reporting procedures are
implemented in the DMS high level language PROTEL, and are
resident in PS. Manual controls by Telco personnel and loader
activity reports are via the normal office I/O facilities, eg. a
designated MAP or teleprinter. One use of this mode is to load a
new generic program into the offline CC while the Active CC
continues to run the office with the old generic.
4.18 The Autoload mode is similar to the Dead Office mode
except that it is activated automatically when the system
determines that the number of office re-initializations in a
specified period of time have exceeded a threshold. When
activated, the Autoloader proceeds to load the contents of an
office image tape into PS and DS without manual intervention.
This mode is particularly useful when an office is unattended.
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(c) NORTHERN TELECOM LIMITED, 1978
NTP 297-1001-107 PAGE 10
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4.19 For detailed bootstrapping procedures, refer to the POP,
NTP 297-1001-500.
CALL TRACING
4.20 The call tracing facility can determine the
characteristics of any connection set up through the office. It
indicates where the specified circuit is connected in the office
if a connection exists. If possible the path through the office
will also be indicated. If no connection exists, the state of
the circuit is determined.
4.21 Call trace requests are originated manually by Telco
personnel or automatically by the system. Manual requests are
initiated in the course of various maintenance procedures such as
line or trunk testing. Automatic traces are initiated as a
result of system detected troubles in the call connection or
Telco initiated camp-on trace requests.
4.22 In both Local and Toll environments, trunks and service
circuits can be traced. Local offices also provide Line Trace
and Calling Line Identification facilities. These allow Telco
personnel to camp-on a specified customer line by requesting an
automatic trace of all calls originating on or terminating to
that line every time it is involved in a call. This provides a
powerful nuisance-call tracing function.
4.23 Manual requests and system outputs are made via a
designated MAP or other I/O device. More details on call tracing
can be found in NTP 297-1001-116 Manual Trunk Testing Description
and NTP 297-YYYY-XXX Manual Line Testing Description. Call
tracing procedures are detailed in POP NTP 297-1001-500.
EQUIPMENT MANUAL MAKE BUSY
4.24 Equipment which is being routined or which has a service
affecting fault can be made unavailable to call processing by the
Manual-Make Busy facility (MMB). Using MMB, office personnel can
isolate faults, perform routine maintenance on equipment, or
extend an existing office without disrupting the system. All
major equipment elements such as CMC, IOC, NM and PM as well as
smaller equipment divisions such as communications busses (i.e.
DMS 100 FAMILY
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the data port), network ports or channels, line circuits, and
trunk circuits can be MMB.
4.25 Requests to make equipment MMB and system reports as to
equipment status are made via the designated MAP or other I/O
device. A request to make equipment MMB when it is already
system made busy results in the system made busy status being
overridden by the MMB request and a report issued to reflect the
new busy status. If the equipment is traffic busy, the MMB
request will 'camp-on' and become effective only when the
equipment is idled. When the equipment does become MMB, a report
is issued to that effect.