4. A data network node has access to a single communications channel which can service individual data packets at a rate of one every 25mSecs. The packet arrival rate per source is 2 packets per second and the network manager must determine the maximum number of data devices which can be supported by the node. In order to do this, three performance criteria have been identified: 1. The channel must not saturate. 2. The average response time associated with each packet must not exceed 100 milliseconds. 3. At any one time, 95% of all packets must experience a delay less than 110 milliseconds. How many sources should be connected to the node? [Hint - a key question in tutorial. Essentially three mini-questions - treat each criteria as a question] [Hint - 1.) not saturate - a definition for utilisation being less than unity. ] [Hint-2.) average response time is mean delay.] Page 1 EE471/971 University of Strathclyde Department of Electronic and Electrical Engineering [Hint - 3.) a learning outcome. The statement above is really the statement of a PDF so need to find a formula for the pdf of the delay - think of an obvious one.]