When we deal with bulk outbound calls sometime there is a chance to miss calls if you are using call file as a mechanism for auto dial out. This is called asterisk choking. when too many files are moved simultaneously into the outgoing directory. Therefore it may be advisable to move them step-by-step with a slight delay.
Solutions to overcome this Asterisk choking
1) Using Manager API is a solution
2) Feed the outgoing folder with less number of calls simultaneously.
3) Find the cause and fix it in the source code.
4) Find out apt time delay between copying of call files.