6.6.28Custom 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 Sync Channel) and the ESC port (if set to Custom). This option is only 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)

 

3=TS32b7&8=XXX 4=TS48=XXX

More/Help

 

 

 

 

 

 

 

 

 

 

 

9

 

Change, Tx/Rx, ESC/Aux/BA Define (IBS) ESC/Aux Custom 1

 

 

O/h use: 1=TS0b1=XXX 2=TS32b1=XXX

 

 

3=TS32b3=XXX 4=TS32b4=XXX

Back Help

 

TS16 and TS48 are both bytes of the overhead structure which 89are free when CAS is not in use, they are each equivalent to 8/32nd of the total overhead and can be allocated to ESC or Aux.

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 different uses by pressing the appropriate numbered key:

---

The overhead locations are unused

ESC

Defined for use by the ESC port

Aux

Defined for use by Aux port

CAS

In use for Channel Associated Signalling

B/A

In use for the Backward Alarm

MFW

In use for the TS32 Multi Frame Word.

TS32 bits 5 and 6 (allocated together) and bits 7 and 8 (allocated together) both correspond to 2/32nds 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 overhead, and are normally spare again see note 1. This bit can only be allocated to the ESC.

TS32 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 configured). Spare if the Aux port is not set to INTELSAT mode 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 selected, and the backward alarm facility has been disabled. This bit can only 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 if Custom IBS mode without a TS32 multiframe is selected. This bit can only be allocated to the ESC.

P300H

P300 Series Modem Installation and Operating Handbook

Page 80

Page 80
Image 80
Paradise P300 specifications Custom IBS Overhead Allocation, Use 1=TS16=XXX 2=TS32b5&6=XXX YES =TS32b7&8=XXX 4=TS48=XXX