Network information technologies Мережні інформаційні технології 1

Network information technologies (Мережні інформаційні технології) 1

Course outline n n n n Corporate network: structure & design Router components & configuration Routing protocols. Static routing. Dynamic routing protocols Access control lists Conserving free IP-addresses WAN technologies. 2

Introduction: early means of communication 3

Modern communications 4

Corporate network: structure & design n Corporate network is a complex system that includes thousands of different components: computers of various types, firmware and software, end user’s workstations and intermediate network devices, cable system etc. 5

n Strategic network planning is to find a compromise between the needs of companies in the automated processing of information, its financial resources and capabilities of information technologies today and in the near future. 6

Structure of corporate network 7

Corporate network: upside down n 1. Computers: centers of information storage and processing n 2. Transport subsystem: data exchange and traffic circulation. LAN&WAN n 3. Network operation systems: Microsoft Windows Server 2003, Microsoft Windows Server 2008, UNIX, Linux, Mac OS X, Novell Net. Ware, and BSD, Cisco IOS n 4. Database management systems (DBMS): My. SQL, Oracle, Microsoft SQL Server, Postgre. SQL n 5. System services: www (HTTP, HTTPs), e-mail (SMTP, POP 3), file transfer (FTP, TFTP), remote access (Telnet) etc. n 6. Specialized software systems: 1 C, Auto. CAD, Protel, client Bank, remote control. 8

New information technologies are focused on: • Increased productivity through the use of new technologies, efficient network devices, rational network structuring • Integration of data, voice and video • High-speed remote access • Bandwidth allocation • Security. 9

Traditional networks n n carry traffic of the traditional computer services (file services, databases, e-mail, web-pages) fluctuation of traffic bandwidth ranging from 10 to 100 kbps distinct channels and different technologies to carry signals 10

Converged networks n n n The flow of voice, video, and data traveling over the same network Distinct networks are consolidated onto one platform High level quality of traffic service 11

Traditional vs. Multimedia applications n n the average bandwidth large short-term traffic activity highly sensitive to packet loss considerable delays are not critical. n n stable average throughput (maybe not very high) large traffic fluctuations loss of packets is possible low delays and their variation 12

13

Congestion (bottleneck) 14

Quality of Service (Qo. S) manages the delay and packet loss parameters on a network, ensuring a successful end-toend application operation. n traffic classification n packet prioritization n bandwidth allocation n congestion avoidance n delays and packet loss management n appropriate level of service defined for each application 15

Examples of priority decisions for an organization: n n Time-sensitive communication - increase (high) priority for services like telephony or video distribution. Non time-sensitive communication - decrease (low) priority for web page retrieval or e-mail. High importance to organization - increase priority for production control or business transaction data. Undesirable communication - decrease priority or block unwanted activity, like peer-to-peer file sharing or live entertainment. 16

Using queues to prioritize communication 17

18

Bandwidth requirements n n n traffic of different applications is combined in one channel; support of continuous growth of the network; high-speed (1 -10 Gbps) trunk links; BW Politics: network resources are distributed differentially to users and applications; congestion avoidance. 19

Security tasks n n to stop unwanted traffic passing to the whole network or its part; to perform packet filtering in order to prevent network overloading; to deliver needed information to authenticated users; to protect information on its way through the public network (e. g. Internet). 20

Hierarchal Network Model n n network is easier to manage and expand, and problems are solved more quickly. involves dividing the network into discrete layers each layer provides specific functions that define its role within the overall network. the network design becomes modular, which facilitates scalability and performance. the typical hierarchical design model is broken up into three layers: access, distribution, and core. 21

Three-layer hierarchical network design 22

Access layer 23

Access Layer - interfaces with end devices, such as PCs, printers, and IP phones; provides access to the rest of the network; needs 10 -100 Mbps throughput (Fast Ethernet); is managed by the protocols of Layer 2 (Data Link); controls collision domains; creates and supports virtual LANs (VLANs); enables port security. The main purpose of the access layer is to provide a means of connecting devices to the network and controlling which devices are allowed to communicate on the network. 24

Distribution layer 25

Distribution layer n n n aggregates the data received from the access layer; controls the flow of network traffic using Qo. S policies and broadcast domains by performing routing functions between LANs or VLANs defined at the access layer; filters data received by means of access control lists (ACL) in order to cut off unwanted or dangerous traffic; needs 1 -10 Gbps (Gigabit Ethernet); is managed by the protocols of Layer 3 (Network); ensures availability of network resources by redundant connections. 26

Core layer 27

Core layer n n n the high-speed backbone of the internetwork; critical for interconnectivity between all distribution layer devices; highly available and redundant; connection to the Internet resources; capable of forwarding large amounts of data quickly. 28

LAN vs. WAN n n n The small geographic area (room, laboratory, department, floor, campus) Full-time access to the network resources without any connection settings Devices used: switch, hub, NIC, wireless access point Bandwidth : 10 Mbps – 10 Gbps Standards: Ethernet, Token Ring, FDDI Services: access to the LAN resourses (files, DB), document printing, common work etc. n n n The large geographical area (cities, countries, continents, remote offices) Full-time and part-time access with connection settings needed Devices used: modems, switches, routers Bandwidth up to 40 MBps Standards: HDLC, PPP, DSL, Frame Relay, X. 25, ISDN Services: www, e-mail, file transfer, IP telephony, videoconferencing, chats, social networks, e-commerce, games, on-line videos etc. 29

Questions ? ? ? 30