PROGRAMMING OF VMux
GENERAL
Operating VMUX requires two distinct steps of setting up and
programming Mux for the desired environment and of monitoring its operation for
status of trunks, user lines and other network parameters. The latter may also
involve reacting to certain alarm conditions by activating alternate
configurations etc.
VMUX comes with a Non-Volatile RAM (NVRAM) which holds at all
times the running configuration or programming of VMUX. This NVRAM comes
pre-programmed from the factory to a default typical configuration. This
default programming can be viewed by the operator on the NMT/ NMS and can be
altered by him to meet installation specific requirements.
The following major parameters are programmable in VMUX and may
be modified from NMT / NMS.
(i) Parameters
related to PCM Trunks
·
Framing format CRC 4/Standard
·
Enable / Disable trunk
·
Time slot cross connection
·
75 / 120 Ohm Line Impedance
(ii) Parameters
related to VF
·
VF Port type : E&M 4W / E&M 2W /Loop IC /Loop
OG/ FXS / FXO / Hotline
·
Trans gain
·
Receive gain
·
Time slot mapping
(iii) Parameters related to Data
(I)
When data card is G703
·
Time slot mapping
(II)
When Data Card is UDT
·
Baud Rate
·
Sync/Async
·
Point to Point / Multidrop
·
Handshaking
·
Time slot mapping
·
Interface selection
(III)
When Data Card is N64
·
Time slot mapping
·
Value of ‘N’
(IV)
When Data Card is UIF
·
Time Slot Mapping
·
Value of ‘N’ (1-2)
·
Interface Selection
(V)
When Data Card is FE1
·
Time Slot Mapping
·
Interface Enable / Disable
·
NMS Enable / Disable
(iv) Parameters related to Network Clocks
·
Programming of network clocks
sources in order of priority
(v) Miscellaneous
parameters
·
Defining all alarms in Mux as
Major/Minor/None
·
Setting up omnibus Conferencing
channels
·
Defining conditions for
activating Mux bypass
·
Defining alarm thresholds for
BER, CRC errors, slip counts
·
Setting up and defining
alternate route configurations in case of major network failures.
PROGRAMMING OF
VMUX
The user interacts with the system from Network Management Terminal
/ NMS connected to 2MB Card. Well
designed user friendly menus display to user the existing parameters as already
programmed and allow user to edit and modify them. The system also checks the new
values entered for consistency and flash any errors encountered.
The Mux configuration can be viewed for display and/or modified at
any time of the Mux operation.
PRINCIPLE OF OPERATION OF VMUX
VMUX does not require constant attendance on NMT or otherwise
for its normal operation. The configuration and features once programmed and
saved in NVRAM guide its operation during normal as well as during alarm
conditions, by automatically activating alternate configurations and/or taking
other actions as programmed by the user. Several indicators on the VMUX are
available however to indicate the status of the Mux and of its various
interfaces to the operator. In addition, the NMT can be used to display the
network and line status in detail, as well as to initiate local and remote diagnostics
to isolate the network problem.
Among the diagnostic aids that can be activated from NMT include
local or remote loop back of an entire trunk or of an individual VF/Data time
slot.
All alarms in the VMUX are categorised by the system (redefinable
by user) as either MAJOR or MINOR or NONE. All major alarms light a alarm LEDs
on the 2MB card and also close major alarm audio and visual dry loops. All such
major alarm dry loops are connected in parallel and brought to the top of the
bay where a major alarm indicator and audio annunciator for the bay is
installed. A similar audio/visual annunciator for minor alarm is also
available. The major & minor alarm annunciators are reset upon operator
acknowledgement.
REMOTE PROGRAMMING OF VMUX
NMS can be used to implement the remote programming of other
VMUX in a network from a single Mux.
