In this paper, we introduce the concept of an additional layer between the Session and Transport layer in the OSI Model, acting as a mediator for all the network communication performed by the application protocols. This network service layer will have to be incorporated in the OS level replacing the default OS' network libraries. Further in the paper we have discussed the benefits offered by implementing this layer in terms of network speed, security, reliability, and application portability. Major security threats like Port Scanning, OS Finger Printing, and TCP Session Hijacking are handled by the layer. In the current Operating Systems design the OS has not much control over the activities performed by the Application Protocol, the OS simply provides an API to create sockets and communicate using them to a remote host via the standard protocols. The HOCS Library will enable the OS to moderate and control the application protocols, this will specifically help in detecting and blocking a Worm attack in the Host system, which is undetectable in the transport layer. Apart from these benefits, the HOCS library will be uniform for different Operating Systems providing transparency and uniformity in the application protocols. Applications developed using the HOCS library will be able to perform the same networking functions on different operating systems. An implementation of HOCS for a server computer is also discussed apart from the conventional client host implementation. © IAEME Publication.