Outline Network Layer and Internetworking The TCP/IP protocol suit ATM MPLS

一、设计应掌握的基础资料 进行活性污泥系统的工艺计算和设计时，首先应比较充分地掌握与废水、污泥有关的原始资料并确定 设计的基础数据，主要有： ①废水的水量、水质及其变化规律； ②对处理后出水的水质要求； ③对处理中产生的污泥的处理要求； ⎯⎯以上属于设计所需要的原始资料

Routing Must choose routes for various origin destination pairs (O/D pairs) or for various sessions – Datagram routing: route chosen on a packet by packet basis Using datagram routing is an easy way to split paths – Virtual circuit routing: route chosen a session by session basis

Broadcast Routing Route a packet from a source to all nodes in the network Possible solutions: – Flooding: Each node sends packet on all outgoing links Discard packets received a second time – Spanning Tree Routing: Send packet along a tree that includes all of the nodes in the network

DestinationAddress Output port number or VC number A packet switch consists of a routing engine (table look-up), a switch scheduler, and a switch fabric

RESERVATION SYSTEMS Single channel shared by multiple users Only one user can use t he channel at a time

Multiple Access Shared Transmission Medium a receiver can hear multiple transmitters a transmitter can be heard by multiple receivers the major problem with multi-access is allocating the channel between the users; the nodes do not know when the other nodes

Responsible for reliable transmission of packets over a link – Framing: Determine t he star t and end of packets (sec 2.5) – Error Detection: Determine w hen a packet contains errors (sec 2.3) – Error recovery: Retransmissio n of packets containing errors (sec 2..4)

Fundamental aspects of network Design and Analysis: – Architecture Layering Topology design – Protocols Pt.-to-Pt. Multiple access End-to-end

4.1 网络信息管理简介 4.2 网络信息管理基本技术 4.3 网络信息的整理 4.4 个人网络信息查询系统的设计 4.5 个人数据库建立