| The Open Shortest Path First (OSPF) routing protocol for IP networks performs inefficiently when operated over multihop, broadcast-based radio channels such as IEEE 802.11. These types of networks are instances of networks known more generally as mobile ad-hoc networks (MANET). The Internet Engineering Task Force (IETF) OSPF working group has been considering proposed extensions to OSPF to enable better performance over such channels. Two proposals for OSPF MANET extensions have been actively developed and discussed; the proposals bear many similarities but differ in the manner in which flooding and topology control are performed. In this paper, we summarize the results of a simulation-based analysis of OSPF MANET design tradeoffs by comparing the design, operation, and performance of the two IETF proposals. Using this data, we explain why we consider an approach known as MANET Designated Routers to be a more natural extension to OSPF in such environments. |