In case your customer wants the ability to randomize callerID you can provide him with this, of course, we cannot support this on our end they will need to set this up themself.
There are 2 ways to get this done.
The simple way which is the one we used is by having a range of DDI's and randomizing on that range.
You do this by editing the conf files as per the below and changing the following.
[t-600] include => t-custom include => t-default
To the following
[t-600]
include => t-custom
exten => _[+*0-9].,1,Set(RANDID=${RAND(1000,1010)})
exten => _[+*0-9].,2,Set(CALLERID(num)=2711100${RANDID})
exten => _[+*0-9].,3,Agi(agi://127.0.0.1)Obviously, you would change the numbers we used to relevant ones for the customer.
The second way we did not try but should follow a similar process and is discussed in the below blog.
https://striker24x7.blogspot.com/2012/03/how-to-set-random-callerid-in-asterisk.html