Return-Path: william@bourbon.usc.edu Delivery-Date: Thu Dec 11 13:40:38 2008 X-Spam-Checker-Version: SpamAssassin 3.2.3 (2007-08-08) on merlot.usc.edu X-Spam-Level: X-Spam-Status: No, score=-2.4 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 mBBLecAR030238 for ; Thu, 11 Dec 2008 13:40:38 -0800 Received: from bourbon.usc.edu (localhost.localdomain [127.0.0.1]) by bourbon.usc.edu (8.14.2/8.14.1) with ESMTP id mBBLhBpr032084 for ; Thu, 11 Dec 2008 13:43:11 -0800 Message-Id: <200812112143.mBBLhBpr032084@bourbon.usc.edu> To: cs551@merlot.usc.edu Subject: Re: Regarding Extra homework problem 4 Date: Thu, 11 Dec 2008 13:43:11 -0800 From: Bill Cheng Someone wrote: > I mean: > If question says to assume the bucket is full initially, why are we starting > with empty bucket in the solution? > Shouldn't we start with full bucket while solving the problem? How? What value should you use? The problem is asking you to find the bucket depth! -- Bill Cheng // bill.cheng@usc.edu On Thu, Dec 11, 2008 at 12:22 PM, Bill Cheng wrote: > Someone wrote: > > > Extra homework problem# 4 says" > > > > (1) * Assuming that the bucket is initially full*, what bucket > depth > > does the flow need for a token rate of 2 packets per second? > > > > (2) Assuming that the bucket is initially full, what bucket depth > > does the flow need for a token rate of 4 packets per second? > > > > But the solution says: > > Let's pretend the bucket volume can be negative. We will have the > > following situation *if we start with an empty bucket (bucket volume = > 0): * > > > > It creates a confusion about what should be the initial bucket > condition. > > It's just a trick to solve the problem! > > I'm not sure what you are asking. > -- > Bill Cheng // bill.cheng@usc.edu