McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Chapter 23 Congestion Control and Quality of Service

McGraw-Hill©The McGraw-Hill Companies, Inc., Data Traffic Traffic Descriptor Traffic Profiles

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.1 Traffic descriptors

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.2 Constant-bit-rate traffic

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.3 Variable-bit-rate traffic

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.4 Bursty traffic

McGraw-Hill©The McGraw-Hill Companies, Inc., Congestion Network Performance

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.5 Incoming packet

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.6 Packet delay and network load

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.7 Throughput versus network load

McGraw-Hill©The McGraw-Hill Companies, Inc., Congestion Control Open Loop Closed Loop

McGraw-Hill©The McGraw-Hill Companies, Inc., Two Examples Congestion Control in TCP Congestion Control in Frame Relay

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 TCP assumes that the cause of a lost segment is due to congestion in the network. Note:

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 If the cause of the lost segment is congestion, retransmission of the segment does not remove the cause—it aggravates it. Note:

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.8 Multiplicative decrease

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure 23.9 BECN

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure FECN

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Four cases of congestion

McGraw-Hill©The McGraw-Hill Companies, Inc., Quality of Service Flow Characteristics Flow Classes

McGraw-Hill©The McGraw-Hill Companies, Inc., Techniques to Improve QoS Scheduling Traffic Shaping Resource Reservation Admission Control

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Flow characteristics

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure FIFO queue

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Priority queuing

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Weighted fair queuing

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Leaky bucket

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Leaky bucket implementation

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 A leaky bucket algorithm shapes bursty traffic into fixed-rate traffic by averaging the data rate. It may drop the packets if the bucket is full. Note:

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Token bucket

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 The token bucket allows bursty traffic at a regulated maximum rate. Note:

McGraw-Hill©The McGraw-Hill Companies, Inc., Integrated Services Signaling Flow Specification Admission Service Classes RSVP

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Integrated Services is a flow-based QoS model designed for IP. Note:

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Path messages

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Resv messages

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Reservation merging

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Reservation styles

McGraw-Hill©The McGraw-Hill Companies, Inc., Differentiated Services An Alternative to Integrated Services

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Differentiated Services is a class-based QoS model designed for IP. Note:

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure DS field

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Traffic conditioner

McGraw-Hill©The McGraw-Hill Companies, Inc., QoS in Switched Networks QoS in Frame Relay QoS in ATM

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Relationship between traffic control attributes

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure User rate in relation to Bc and Bc + Be

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Service classes

McGraw-Hill©The McGraw-Hill Companies, Inc., 2004 Figure Relationship of service classes to the total capacity