zaptel.conf details

This is the original /etc/zaptel.conf file used to configure your zap channels:
Note: Settings/Parameters irrelevant to Sangoma TDM Cards have been removed
This file is parsed by the Zaptel Configurator, ztcfg

First come the span definitions, in the format
span=<span num>,<timing source>,<line build out (LBO)>,<framing>,<coding>[,yellow]

All T1/E1 spans generate a clock signal on their transmit side. The  <timing source> parameter determines whether the clock signal from the far  end of the T1/E1 is used as the master source of clock timing. If it is, our own clock will synchronise to it. T1/E1's connected directly or indirectly to a PSTN provider (telco) should generally be the first choice to sync to. The PSTN will never be a slave to you. You must be a slave to it.

Choose 1 to make the equipment at the far end of the E1/T1 link the preferred source of the master clock. Choose 2 to make it the second choice for the master clock, if the first choice port fails (the far end dies, a cable breaks, or whatever). Choose 3 to make a port the third choice, and so on. If you have, say,  2 ports connected to the PSTN, mark those as 1 and 2. The number used for each port should be different.

If you choose 0, the port will never be used as a source of timing. This is appropriate when you know the far end should always be a slave to you. If the port is connected to a channel bank, for example, you should always be its master. Any number of ports can be marked as 0.

Incorrect timing sync may cause clicks/noise in the audio, poor quality or failed faxes, unreliable modem operation, and is a general all round bad thing.

The line build-out (or LBO) is an integer, from the following table:

0: 0 db (CSU) / 0-133 feet (DSX-1)
1: 133-266 feet (DSX-1)
2: 266-399 feet (DSX-1)
3: 399-533 feet (DSX-1)
4: 533-655 feet (DSX-1)
5: -7.5db (CSU)
6: -15db (CSU)
7: -22.5db (CSU)

The framing is one of "d4" or "esf" for T1 or "cas" or "ccs" for E1

Note: "d4" could be referred to as "sf" or "superframe"

 The coding is one of "ami" or "b8zs" for T1 or "ami" or "hdb3" for E1

 E1's may have the additional keyword "crc4" to enable CRC4 checking

 If the keyword "yellow" follows, yellow alarm is transmitted when no channels are open.

span=1,0,0,esf,b8zs
span=2,1,0,esf,b8zs
span=3,0,0,ccs,hdb3,crc4

 Next come the definitions for using the channels.  The format is:
 <device>=<channel list>

 Valid devices are:
"e&m"     : Channel(s) are signalled using E&M signalling (specific implementation, such as Immediate, Wink, or Feature Group D are handled by the userspace library).
"fxsls"   : Channel(s) are signalled using FXS Loopstart protocol.
"fxsgs"   : Channel(s) are signalled using FXS Groundstart protocol.
"fxsks"   : Channel(s) are signalled using FXS Koolstart protocol.
"fxols"   : Channel(s) are signalled using FXO Loopstart protocol.
"fxogs"   : Channel(s) are signalled using FXO Groundstart protocol.
"fxoks"   : Channel(s) are signalled using FXO Koolstart protocol.
"unused"  : No signalling is performed, each channel in the list remains idle

 The channel list is a comma-separated list of channels or ranges, for example:

1,3,5 (channels one, three, and five)
16-23, 29 (channels 16 through 23, as well as channel 29

So, some complete examples are:
e&m=1-12
fxsls=25,26,27,28
fxols=29-32

Finally, you can preload some tone zones, to prevent them from getting overwritten by other users (if you allow non-root users to open /dev/zap/*  interfaces anyway.  Also this means they won't have to be loaded at runtime.

The format is "loadzone=<zone>" where the zone is a two letter country code.

You may also specify a default zone with "defaultzone=<zone>" where zone is a two letter country code.

An up-to-date list of the zones can be found in the file zaptel/zonedata.c

loadzone = us
loadzone = us-old
loadzone=gr
loadzone=it
loadzone=fr
loadzone=de
loadzone=uk
loadzone=fi
loadzone=jp
loadzone=sp
loadzone=no
loadzone=hu
loadzone=lt
loadzone=pl
defaultzone=us