Manual

99

There are dozens of factors that can aect the success or failure of a POTS codec call, some within the user’s control and
some not. Here’s a short list of rules to follow for POTS codec connecons:
1 Use the POTS codec on a direct telephone company line and avoid in-house phone systems. A line
used by a fax machine usually provides this direct access. (Be sure to disconnect the fax machine
before connecng the codec!)
2 Check to see that there are no extensions or modems on the line you are using—or at least arrange
that no one uses these during your broadcast.
3 If there is call-waing on your line, disable it by entering “*70” in front of the number you are
dialing.
4 If possible, try the POTS codec out at the remote site before your actual broadcast at about the
same me of day that you plan to use it. This will give you a good idea of expected connect rates
and possible line problems.
5 At minimum, connect a few minutes before airme to assess the connecon quality. Seng a
MaxRate on the POTS codec, based on your ndings, is highly recommended. MaxRate usually
should be set at a level or two below the maximum unrestricted rate. This will provide a “guard
band” of sorts against noise and corrupon which may cause errors on the line.
6 If operaon starts to degrade aer a long period of connecon, it may be that the phone line
parameters have changed. These parameters are aected by factors such as me of day, weather
and geographic locaon. The modems should be given the opportunity to renegoate for these
new parameters.
7 If you experience low connecon rates or errors, try redialing. If that does not help, dial from the
other end. If the call is long distance, try forcing the call to another carrier. If a good connecon is
found, keep that line up.