Hi, I have 18 years of experience in VOIP and asterisk. I offer my services for your project. Please have a look at my profile to see all my experience details. I assure you of a high quality professional service. I am one of top voip developers available with freelancers. We can chat out details. This price is if you already have a running asterisk system and just need me to implement the dynamic caller id, else if I have to do from scratch it will be a higher price.