Towards Variable Length Addressing for Scalable Internet Routing

The Internet is facing the accelerating growth of routing table size. Backbone routers' routing table has already reached 512k entries, which has a negative effect on the scalability of the Internet. Hierarchical addressing and locator/ID separation solutions have been proposed to address the scalability issue. However, there has been little focus on how to efficiently represent hierarchical location addresses for a large scale distributed network, such as today's Internet. In this paper, we present a variable-length address encoding method to represent hierarchical location addresses. Our analysis and evaluation results show that 1) it is difficult to use fixed-length encoding to represent hierarchical location addresses for a large scale network; and 2) the proposed variable-length addresses could guarantee the scalability property of hierarchical addressing, and alleviate the inefficiency of address space due to fixed-length addresses.