Telos ZephyrExpress User Manual
Page 150
9-8 TROUBLESHOOTING
Near Loopback for codec testing
When the
Codec: Loopback
menu item is set to
Near
, incoming audio gets coded in the
usual manner, sent into the ISDN interface but then looped directly back to the decoder.
This checks over 90% of ZephyrExpress’ functionality with no ISDN line present.
w
IMPORTANT NOTE!
If you are using the European ISDN TA and aren’t connected to an active ISDN
line, you will hear dropouts in the audio signal during Near Loopback. This is not
a problem with the equipment.
c
COMPATIBILITY NOTE!
Near Loopback requires both the transmit and receive coding methods to be
compatible.
?
CURIOSITY NOTE!
Near Loopback is great for trying ZephyrExpress’ audio coding algorithms with-
out an ISDN line, and getting used to what the different settings sound like. It’s
also great for impressing people with the quality that ISDN can yield over a
good system.