[asterisk@iml-v20z-11 asterisk]$ cat zapata.conf
[channels]
context=pri
switchtype=national
overlapdial=yes
signalling=pri_cpe
group=1
accountcode=pbx
channel => 1-23
channel => 25-47
channel => 49-71
channel => 73-95
resetinterval = never


$ cat /etc/zaptel.conf
[snip]
defaultzone=us
loadzone=us
span=1,1,0,esf,b8zs,yellow
bchan=1-23
dchan=24
span=2,1,0,esf,b8zs,yellow
bchan=25-47
dchan=48
span=3,1,0,esf,b8zs,yellow
bchan=49-71
dchan=72
span=4,1,0,esf,b8zs,yellow
bchan=73-95
dchan=96