S100U as first zaptel device
/etc/zaptel.conf: fxoks=1
/etc/asterisk/zapata.conf context=home signalling=fxo_ks group = 1 channel => 1
cat /proc/zaptel/1 output: Span 1: WCUSB/0 "WCUSB/0 0" 1 WCUSB/0/0 FXOKS