Implementation of authentication and service selection based on user id and password with DHCP using CHAP and RADIUS

Other than its usage in the local area networks, Ethernet has also become widespread in the access and aggregation networks during the last few years. In addition to Internet access services, voice and video services are also started to be provided over DSL lines. These two major changes lead using DHCP in these area. To prevent additional infrastructural and operational costs, it?s also possible to use DHCP instead of PPP based access methods which are currently and commonly being used in DSL Internet access services. However it?s not possible to perform some operations like ?user authentication? and ?service selection? using the current capabilities of DHCP while these can easily be handled by using PPP. This situation causes hesitations in using DHCP instead of PPP. In this work, ?Implementation of authentication and service selection based on user id and password with DHCP using CHAP and RADIUS? has been studied. Firstly, some brief information has been given about the protocols related with the subject and compared with each other. Then, necessary criteria which should be met with a proper solution have been identified and related works done until today have been observed by comparing them with the identified criteria and by exposing their missing points. As a result of these research and observations, a solution has been proposed and designed to completely meet the identified criteria. In order to check whether it is possible to implement the proposed solution, sample applications which are representing DHCP client and server have been written by using C programming language. These applications have been tested in an environment including a RADIUS server and as a result of the tests it?s concluded that the proposed solution meets the identified criteria and is compliant with the current DHCP and RADIUS RFCs and can be put in practice. Keywords: DHCP, Authentication with DHCP, Service selection with DHCP, RADIUS, authentication, user authentication, DHCP and RADIUS.