The application layer is where network applications and their application layer protocols reside. The internet application layer includes many protocols such as the HTTP ( which provides for web document request and transfer) SMTP ( which provides for the transfer of e mail message) and FTP ( which provides for the transfer of tiles between two end systems. We ii se that certain network functions such as the translation of human friendly names for internet end systems like Gaia. Cs yahoo. Com to a 32 bits networks address are also done with the help of an applications layer protocol the domain name systems ( DNS).