Return-Path: william@bourbon.usc.edu Delivery-Date: Sat Oct 18 14:51:00 2008 X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on merlot.usc.edu X-Spam-Level: X-Spam-Status: No, score=-2.3 required=5.0 tests=AWL,BAYES_00 autolearn=ham version=3.2.3 Received: from bourbon.usc.edu (bourbon.usc.edu [128.125.9.75]) by merlot.usc.edu (8.14.1/8.14.1) with ESMTP id m9ILp0NU018119 for ; Sat, 18 Oct 2008 14:51:00 -0700 Received: from bourbon.usc.edu (localhost.localdomain [127.0.0.1]) by bourbon.usc.edu (8.14.2/8.14.1) with ESMTP id m9ILxkcd024835 for ; Sat, 18 Oct 2008 14:59:46 -0700 Message-Id: <200810182159.m9ILxkcd024835@bourbon.usc.edu> To: cs551@merlot.usc.edu Subject: Re: Landmark routing Date: Sat, 18 Oct 2008 14:59:46 -0700 From: Bill Cheng Someone wrote: > I had a question about slide 9 of lecture 8. During the lecture after node 8 > was promoted to LM2 we verified the red rule. Yes. You need to verify the red rule for i=1, i.e., "every LM1 router is seen by at least one LM2 router". > Was this necessary since we > already verified that Node 3 was an LM1 router than could see everyone (you > could route downward to everyone with this information). Wouldn't we only > need to recheck the red rule if we had needed multiple level 1 routers > (which were potential "far" away from each other) to satisfy the red rule in > the previous iteration. May be for the particular network it works out. But in general, we must check after every round. -- Bill Cheng // bill.cheng@usc.edu