[solved]Zap group always get busy for a certain phone number

I have outbound routes use a pri line. It’s configured as group 1. Most outbound routes can dial correctly but I have 1 phone number that usually get the busy signal. Here’s some examples of the dialing plan.

exten => s,1,Answer()
exten => s,n,Dial(ZAP/20/THE_PHONE_NUMBER)
exten => s,n,Hangup()

exten => s,1,Answer()
exten => s,n,Dial(ZAP/g1/THE_PHONE_NUMBER)
exten => s,n,Hangup()

I also have an outbound route set up with FreePBX 2.3 on Asterisk 1.2.24 which dials group 1 as well but that one never works. The issue isn’t a provider issue since the call can be completed and I have verified with the provider that it’s not the provider.

Here’s /etc/asterisk/zapata.conf:
;pri span with bchan 1-23 and dchan 24
channel => 1-23

My second question is if I can break up the channels into multiple groups. For example, group 1 will be the first 15 channels and group 2 will be the rest.

The key to this problem was having my caller id set to “1800xxxxxxx”. By removing the leading “1”, I was able to solve the problem. It could be the other end rejecting the call since they don’t like the 1-areacode-phonenumber format.