[trunkgroups]

trunkgroup=>1,24
spanmap => 1,1,0
spanmap => 2,1,1
spanmap => 3,1,2
spanmap => 4,1,3

[channels]

switchtype=national
signalling=pri_cpe
pridialplan=unknown
prilocaldialplan=unknown
usecallerid=yes
callerid=asreceived
echocancel=yes
echocancelwhenbridged=yes
echotraining=yes
rxgain=0.0
txgain=0.0
musiconhold=native
language=en
context=CMG

group = 1
channel => 1-23,25-72