Extensions to DNS for supporting internationalized domain names

Abstract

As the Internet become popular around the globe, there have been several approaches to support internationalized domain names, that is, names consisting of non-ASCII characters. However, they require modification of existing applications or significant changes in the existing DNS protocol. In this paper, we propose an extension to the existing DNS protocol for supporting internationalized domain names while maintaining interoperability and compatibility with the DNS. For this, we exploit the reserved field of Opcode in the DNS query to support Internationalized Domain Names. The proposed scheme uses a UTF-8 encoding scheme as a wire format since it allows ASCII names to remain intact. We implement the proposed scheme using BIND 8.2.1 on Solaris, Sun Unix OS. The performance results show that the proposed scheme does not incur any significant overhead while it maintains the interoperability and compatibility with the existing DNS.