TAILIEUCHUNG - Giới thiệu về IP và ATM - Thiết kế và hiệu suất P16

FIRST-IN FIRST-OUT BUFFERING In the chapters on packet queueing, we have so far only considered queues with first-in-first-out (FIFO) scheduling. This approach gives all packets the same treatment: packets arriving to a buffer are placed at the back of the queue, and have to wait their turn for service, . after all the other packets already in the queue have been served. If there is insufficient space in the buffer to hold an arriving packet, then it is discarded. In Chapter 13, we considered priority control in ATM buffers, in terms of space priority (access to the waiting space) and time. | Introduction to IP and ATM Design Performance With Applications Analysis Software Second Edition. J M Pitts J A Schormans Copyright 2000 John Wiley Sons Ltd ISBNs 0-471-49187-X Hardback 0-470-84166-4 Electronic 16 IP Buffer Management packets in the space - time continuum FIRST-IN FIRST-OUT BUFFERING In the chapters on packet queueing we have so far only considered queues with first-in-first-out FIFO scheduling. This approach gives all packets the same treatment packets arriving to a buffer are placed at the back of the queue and have to wait their turn for service . after all the other packets already in the queue have been served. If there is insufficient space in the buffer to hold an arriving packet then it is discarded. In Chapter 13 we considered priority control in ATM buffers in terms of space priority access to the waiting space and time priority access to the server . These mechanisms enable end-to-end quality-of-service guarantees to be provided to different types of traffic in an integrated way. For IP buffer management similar mechanisms have been proposed to provide QoS guarantees improved end-to-end behaviour and better use of resources. RANDOM EARLY DETECTION - PROBABILISTIC PACKET DISCARD One particular challenge of forwarding best-effort packet traffic is that the transport-layer protocols especially TCP can introduce unwelcome behaviour when the network or part of it is congested. When a TCP connection loses a packet in transit . because of buffer overflow it responds by entering the slow-start phase which reduces the load on the network and hence alleviates the congestion. The unwelcome behaviour arises when many TCP connections do this at around the same time. If a buffer is full and has to discard arriving packets from many TCP connections they will all enter the slow-start phase. This significantly reduces the load through the buffer leading to a period 268 IP BUFFER MANAGEMENT of under-utilization. Then all those TCP connections will .

• Kĩ thuật Viễn thông
• Thiết kế IP
• hiệu suất IP
• thiết kế ATM
• hiệu suất ATM
• công nghệ Mode
• lưu lượng IP WDM
• thiết kế
• lưu lượng IP
• tín hiệu
• kết nối IP
• dung lượng băng thông
• viễn thông
• mạng máy tính
• mạng IP WDM