[trunkgroups] [channels] switchtype=euroisdn signalling=pri_cpe usecallerid=yes callwaiting=yes usecallingpres=yes callwaitingcallerid=yes threewaycalling=yes transfer=yes canpark=yes cancallforward=yes callreturn=yes echocancel=no echocancelwhenbridged=no group=1 callgroup=1 pickupgroup=1 channel => 1-15 channel => 17-31