P300H
P300 Series Modem Installation and Operating Handbook
Page 138
IDR o/h: [?] 1=Normal:96k 2=1xAudio:64k
3=No Audio:32k 4=16k ADPCM modes
Change, Tx/Rx, Service, Custom, IDR, Overhead Menu
If
ïêµ ßÜÐÝÓ ÓÑÜÛÍ
are selected the following further prompt appears
IDR o/h: [?] 1=96k:2x16k-Audio+32k-BER
2=64k:2x16k-Audio only
Change, Tx/Rx, Service, Custom, IDR, O/H 16k Menu
The modes selected by these two menu's are as follows:
ÒÑÎÓßÔæçêÕ
The normal IDR overhead is used
ïÈßËÜ×ÑæêìÕ
The overhead is reduced to 64kbps, the 32kbps defined for Audio ESC channel
2 is not transmitted. The 32kbps for [FAS + Back Alarms + 8K sync ESC
channel], and Audio ESC channel 1 are still transmitted.
ÒÑ ßËÜ×ÑæíîÕ
The overhead is reduced to 32kbps, both 32kbps channels defined for ESC
audio are not transmitted. The 32kbps for [FAS + Back 8K sync ESC
channel] alone is transmitted.
16k Modes
çêÕ
Both Audio ESC channels operate in 16kbps ADPCM mode allowing both
audio ESC's to fit into 32kbps. The 32kbps for [FAS + Back 8K sync
ESC channel] is transmitted first, followed by 32kbps defined for Audio ESC 1,
now containing both Audio ESCs 1 & 2 using 16kbps ADPCM
. These are
followed by the
32kbps for Audio ESC channel 2, which is unused
and may
be defined for use by the Aux port providing either a spare 32kbps for external
BER testing, or for the use of the internal BER Tester (in both cases for
possible traffic quality monitoring).
êìÕ
Both Audio ESC channels operate in 16kbps ADPCM mode allowing both
Audio ESC's to fit into the 32kbps allocated to audio ESC channel 1. The
overhead is 64kbps comprising 32kbps for [FAS + Back 8K sync ESC
channel] plus 32kbps containing the two 16kbps ADPCM audio channels. The
final 32kbps defined for Audio ESC channel 2 is not transmitted.