How to configure

I installed the elastix asterisk in our server and test the outgoing call but when I check in the flash operator panel in GUI of elastix asterisk the outbound call goes to zap21 . When I try to call from outside to the office, the call inbound goes to zap 13 or 14 or 15. how will I configure the outbound calls so that it will goes to zap 13 or 14 or 15.

[root@elastix ~]# cd /etc
[root@elastix etc]# cd asterisk
[root@elastix asterisk]# vi zapata-channels.conf
; Autogenerated by /usr/sbin/genzaptelconf – do not hand edit
; Zaptel Channels Configurations (zapata.conf)
;
; This is not intended to be a complete zapata.conf. Rather, it is intended
; to be #include-d by /etc/zapata.conf that will include the global settings
;

; Span 1: WCTDM/0 “Wildcard TDM2400P Board 1” (MASTER)
;;; line="1 WCTDM/0/0"
signalling=fxs_ks
callerid=asreceived
group=0
context=from-pstn
channel => 1
context=default

;;; line="2 WCTDM/0/1"
signalling=fxs_ks
callerid=asreceived
group=0
context=from-pstn
channel => 2
context=default