CAD = Cash against documentation
if payment terms are written in documentation CAD via bank the it is DP & considered as very safe in done in proper way....
See this link : http://exportimport.guru/discussionforum/single/is-100-dp-safe-payment-terms-for-export-business-what-precautions-we-must-take-in-a-deal
but if only CAD done without bank, i.e documentation are sent directly to importer then it is most unsafe way to do business because after receiving the documentation, the importer might not release the payment and he will get delivery of goods once he has original BL.