Custom Ibs Overhead Allocation - Paradise Datacom P300 Series Installation & Operating Handbook

6.6.28 Custom IBS Overhead Allocation

Several of the above paths lead to the following screen where the available overhead can be allocated
between the Aux port (if set to
available of the `Custom Features` feature is available (standard P300-TCM).
This sophisticated facility allows the operator for example to:
On high rate links specify a low proportion of the overhead to be assigned to the ESC channel
(still enough to provide the require async Baud rate) but then allocate the remaining overhead to
the Aux port configured for a Sync Channel, allowing external access to the rest of the overhead
for example other data or BER testing (internal or external).
When using Custom, IBS, Min overhead, allocate the overhead between ESC & Aux ports. The
overhead will scale to provide the set ESC Baud rate however much of the overhead is
assigned to it, and increase / reduce the total overhead as appropriate. The remainder of the
overhead can be allocated to the Aux channel, again for extra data of BER testing (internal or
external). This effectively allows the sync channel rate to be varied (by changing the ESC rate
& overhead ESC assignment, which the overhead then adjusts to provide).
The screens are as follows:
O/h use: 1=TS16=XXX 2=TS32b5&6=XXX (YES)
Change, Tx/Rx, ESC/Aux/BA Define (IBS) ESC/Aux Custom 1
Change, Tx/Rx, ESC/Aux/BA Define (IBS) ESC/Aux Custom 2
Each of the `XXX` fields can display the following uses for that part of the overhead, and be toggled
between the differen t uses by pre
TS1 6 and TS48 are both bytes of the overhead structure which are free when CAS is not i
are each equivalent to 8/32nd of the total overhead and can be allocated to ESC or Aux.
TS3 2 bits 5 and 6 (allocated together) and bits 7 and 8 (allocated together) both correspond to 2
of the overhead. These are normally spare, see note 1, and can be allocated to ESC or Aux.
TS0 bit 1 is 1/32nd of the
allocated to the ESC.
TS3 2 bit 1 is 1/32nd of the overhead, and is the bit allocated by INTELSAT for the low rate oversampled
ESC (available on the Aux port if so configu
or Note 1, can be allocated to ESC or Aux.
TS32 bit 3 is 1/32nd of the overhead and is normally used for the backward alarm, but is spare if
Custom IBS mode is sele
be allocated to the ESC.
TS32 bit 4 is 1/32nd of the overhead and is normally used for the Satellite TS32 Multiframe but is spare
P300H P300 Series Modem Installation and Operating Handbook
) and the ESC port (if set to
3=TS32b7&8=XXX 4=TS48=XXX More/Help
O/h use: 1=TS0b1=XXX 2=TS32b1=XXX
3=TS32b3=XXX 4=TS32b4=XXX Back Help
ssing the appropriate numbered key:
The overhead locations are unus
Defined for use by the ESC p
Defined for use by Aux port
In use for Channel Associated S
In use for the Backward Alarm
In use for the TS32 Multi Frame Word.
overhead, and are normally spare again see note 1. This bit can only be
red). Spare if the Aux port is not set to INTELSAT mode
cted, and the backward alarm facility has been disabled. This bit can only
). This option is only
ed
ort
ignalling
n use, they
/32nds
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