Change, Tx/Rx, Service, Closed Network - Paradise Datacom P300 Series Installation & Operating Handbook

to the data. In this mode the equipment is compatible with OEM modems used
with a P1300 framing unit, or other `IDR` equipment from other vendors. Refer
to section "IDR Service Features" in Appendix F on page 219 for a full
description of IDR features.
This allows the operator to select a framing format based on the standard
IBS/SMS or IDR definitions, but with non-standard or extra features such as
Minimum overhead framing, or Multidestinational IBS. A description of the
features and menus which follow this choice are in section 7 "Change, Tx/Rx,
Service, Custom Menu" on page 135.
6.6.2

Change, Tx/Rx, Service, CLOSED NETWORK

These screens are only shown if the Async ESC feature is available, standard on the P300-IBS and
above.
Note: Closed Net Plus ESC is available with the P400 series modems, refer to Closed Network Plus
ESC via the Custom Service menu in section 8.7.2 on page 150.
When Closed Net is selected the following screen is shown to allow the selection of normal
operation, or
Change, Tx/Rx, Service, Closed Net, ESC Menu
The modem operates without adding any overhead to the data, this is `normal`
Closed Network mode. Normal
and is compatible with other closed network equipment such as the Paradise
P200, and closed network equipment from other vendors.
The modem adds the minimum possible overhead to the satellite data (down to
<1%) to support the async ESC rate you set. The exact overhead used can
be viewed on the Info, View Config, Tx/Rx screens. It provides the following
facilities:
Note: As the overhead affects the final composite framed data rate, and the
ESC & backward alarm settings determine the required overhead, then for two
modems to interwork the following parameters must match on both pieces of
P300H P300 Series Modem Installation and Operating Handbook
:
Closed Network mode [?]:
1=No ESC (normal) 2: Plus ESC (min o/h)
A variable rate ESC channel (up to approx 70% of main channel rate)
An optional backward alarm facility.
At rates of 32kbps and above it provides a synchronous scrambler to
replace the error multiplying V.35 normally used on closed network
links.
If used with Drop/Insert (Yes, Closed Network with Drop/Insert), it
provides Timeslot ID maintenance across the link.
See the first few paragraphs of Appendix F where Backward Alarms,
Synchronous Scrambling, and Timeslot ID Maintenance are discussed (in
relation to an IBS/SMS carrier).
equipment:
Main data rate.
Async ESC Baud Rate, Character length and Parity.
Backward Alarm option (ie both enabled or both disabled).
adds no overhead to the data
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