Internet application performance over wireless links is disappointing due to wireless impairments that adversely affect higher layers. This paper focuses on link layer enhancement mechanisms that hide wireless errors from the rest of the Internet. We simulated file transfer and WWW browsing over TCP and continuous media distribution over UDP, in conjunction with various link layer schemes. Our results reveal that WWW browsing has substantially different behavior than file transfer, that existing TCP enhancement schemes have limited applicability and that UDP applications are best served by schemes inappropriate for TCP. Therefore, multiple link layer solutions are needed to optimize the performance of diverse applications.