Networking

1. Networking Chapter 12

2. Areas of Discussion OSI Model IP Addressing Local Area Networks Wide Area Networks Remote Access Network Management Voice and Data Convergence Additional Resources

3. OSI Model Application Layer Presentation Layer Session Layer Transport Layer Network Layer Data Link (MAC) Layer Physical Layer

4. Internet Protocol Suite What is a protocol? Set of rules and standards that ease the interconnectivity of devices of different platforms and from different vendors. TCP/IP: Transmission control protocol/Internet protocol Application Layer (session, presentation, and application) Transport Layer (transport) Inter-network (network) Link (physical and data link)

5. IP Addressing IP addressing: 32-bit string 4 eight-bit numbers Each eight-bit number is an octet Can be value of 0 to 255 Network address and host address Subnet masks Class A 1-126 Class B 128-191 Class C 192-223

6. A Shortage of Addresses American Registry for Internet Numbers (ARIN) 1997 registers and administers IP numbers for North America. Other global regions are managed by RIPE NCC, LACNIC, and APNIC. Running out of numbers Solutions: Network Address Translation IPv6

7. Network Address Translation Translates your internal network addresses into the public address assigned to your Internet connection. However, there are agreed upon standards for private internal networks: 10.0.0.0 � 10.255.255.255 (1 class � A range) 172.16.0.0. � 172.31.255.255 (16 class � B ranges) 192.168.0.0. � 192.168.255.255 (256 class � C ranges)

8. IPv6: IP next generation or IPng IPv4 allows for approximately 4 billion addresses IPv6 allows for 340 undicillion (340 followed by 36 zeroes) addresses. Changes from a 32-bit address to a 128-bit address

9. DNS: Domain Name Server: translates alphanumeric names to IP addresses A DNS allows you to name your servers and devices and translates those names to IP addresses The DNS environment of the Internet allows you and your users to use meaningful names (like browser URLs), as opposed to IP addresses.

10. DHCP Dynamic Host Configuration Protocol (DHCP): automatically assigns IP addresses. Some devices need to have static addresses such as printers, which recognize MAC addresses Greatly eases the burden of IP administration

11. Local Area Networks Network that connects the devices in one geographic location. As a general rule, a LAN�s boundary is telecommunication facilities and a router. LAN is dependent on needs, plans for future growth, and changes of use. Ethernet is the de facto standard.

12. LAN Design Goals of a good LAN design Maximizing the efficiency of network traffic Reliability Manageability: growth and traffic patterns, bottlenecks, and problem areas Flexibility Location of devices Traffic volume

13. The Core Network Single device or multiple devices Features of Switches Number and types of connections required Total throughput Redundancies Forwarding methods: store and forward, cut-through forward, fragment free Layer 2 and Layer 3 Chassis or Stackable

14. Wireless LANs WiFi (wireless fidelity) up to 300 feet Eliminates need for running cabling Wireless security Wired equivalent privacy (WEP): the first method developed for securing wireless LANs. �Key� (either 40 or 128 bits in length). Easy to hack. WiFi protected access (WPA): Temporal Key Integrity Protocol (TKIP), developed overcome weakness of WEP. Changes the key with each data frame. Built-in authentication

15. Wireless security Hidden SSID: Service Set Identifier: Environment with multiple wireless networks, SSID identifies which network is which. MAC Filtering: allow only predetermined devices to connect to it by specifying the MAC address of authorized devices. Internet Access only: connects to Internet only. Must use other remote access solutions to connect to private internet.

16. Bluetooth: shorter range of typically 30 feet Is considered a wireless alternative for USB-type connections while WiFi is considered a wireless alternative for Ethernet connections.

17. Wide Area Networks Connects the remote locations via telecommunication facilities (T-1 lines, ISDN, etc.) Span large distances Design based upon geography, traffic flow, and volumes.

18. Difference between LANs and WANs Majority of LAN costs are up-front capital expenditures of cable installation and hardware. Majority of WAN costs are recurring operating costs of lines.

19. Considerations for a WAN Need for high-speed transmissions Need for 24/7 operations User needs: locations, travel Backup/fail-over capabilities and facilities: most critical connections need to be most reliable Installation delays: the more sophisticated the line, the more time your telecommunications vendor will need to install it.

20. Routers: key devices for WANs Forwards data to another network Occurs at Layer 3 of OSI model Acts as transfer point between two networks to pass data packets between them Routing table is used by the routers to determine the best path to use for each data packet

21. Key WAN Technologies Connectivity Options Point-to-point circuits: leased, dedicated, and private lines T-1 line: 24 channels of 64 Kbps, for an aggregate throughput of 1.544 Mbps T-3 line: (often referred to as DS3) transmission speeds of 44,736 Mbps, via 672 circuits, each of 64 Kbps transmission Fractional T-1 or fractional T-3. See page 329.

22. continued Connectivity Options Dial-up Plain Old Telephone System (POTS) line Based on analog technology 56 Kbps

23. continued ISDN: Integrated Services Digital Network Digital transmission over standard copper telephone wire Basics Rate Interface (BRI): homes and small businesses Two 64Kbps B channels and one 16 Kbps D channel B channel carries the data and D channel carries signaling Throughput total of 128 Kbps Primary Rate Interface (PRI) larger sites 23 B channels and one 64 Kbps D channel Throughput total of 1.4 Mbps Dial their calls similar to the way POTS lines do Often used for back up of T1-lines

24. continued Broadband (cable modems and DSL) past definition: connection type that can carry more than one signal at a time Today: high-speed connection to the Internet Offer faster downstream rate than upstream rate Always on DSL: digital subscriber line. Phone company offering to bring high-speed Internet to homes and small businesses over standard copper phone lines. Always on High-speed downstream Must be within few miles of telephone company central office

25. Continued Broadband (cable modems and DSL) Cable TV companies deliver high-speed Internet access. Speed is often 384 Kbps upstream and 2 Mbps downstream

26. Continued Packet switching (ATM and frame relay) Breaks up data transmission into small packets Asynchronous Transfer Mode (ATM) and Frame Relay: Frame relay speeds between 56 Kbps and 45 Mbps ATM speeds between 25 to 622 Mbps Used for delay-sensitive applications like voice and video plus data Frame relay and ATM provided by telecom carriers ATM : Sustained Information Rate (SIR) Frame Relay: Committed Information Rate (CIR) Data below this level will be guaranteed delivery; if dropped, will be retransmitted

27. Continued High-speed Internet Connection to the Internet Point-to-point circuits Broadband Fees for line to your office Fees for Internet access Virtual Private Networks (VPNs): using security and tunneling techniques, establish a VPN via the Internet to connect sites Split tunneling: remote offices connect to the Internet and establish a VPN back to headquarters while local Internet access goes directly to Internet

28. Remote Access Companies are now available 24/7 The Choices Your connection path Internet access Direct access Handheld device What you Connect to Web-based applications Remote control Remote node Handheld device applications Replication (synchronization)

29. Questions What are the needs of your customers? Based upon the answer, select your options

30. The Connection Path Three options for connection Through the Internet Through a direct connection Through the air waves using a handheld device

31. Continued What You Connect To Web-based applications Microsoft�s outlook Web Access (OWA) or iNotes from Lotus Notes Remote control Establish a connection Establish a remote control session Centralized Remote control Terminal servers Remote node Handheld device applications Replication (Synchronization): use applications and items are saved, when connected, can transmit to main headquarters.

32. Advantages: reduces time needed for connection Users can work regardless of whether or not they have connectivity Disadvantages: Applications must be same for best results: XP vs. Vista

33. Continued Security for Remote Access Firewalls VPNs: used for connections that come via the Internet to encrypt the data. Point-to-point Tunneling Protocol: losing popularity L2TP: combines two secure communication protocols: Cisco Systems� Layer Two Forwarding (L2F) and Microsoft�s PPTP. IPSec: algorithms and a public key to encrypt the data at Layer 3. Also uses Internet Key Exchange (IKE) protocol to authenticate the two end nodes in the communication session. Two modes: transport mode, only the data portion of the packet is encrypted, but not the header In tunnel mode: both the header and the data are encrypted

34. Continued Radius: Remote Authentication Dial-In User Service (RADIUS) User attempts to dial in to a remove access device, device authenticates, user is routed to network; otherwise; disconnected.

35. Network Management Finding problems Vendors generally offer management functionality that allows you to collect data about the network Can purchase management tools Management Tools SNMP: Simple Network Management Protocol: works by sending messaged, called protocol data units (PDUs), to various devices on the network. SNMP-compliant devices, called agents, store data about themselves in Management Information Bases (MIBs) and return this data to the SNMP requesters.

36. Management Tools RMON: remote monitoring takes SNMP to the next level. While SNMP manages devices, RMON can monitor the actual network traffic, collect statistics, and record history.

37. Quality of Service (QoS) and Bandwidth Management QoS allow you to prioritize types of traffic or applications Gives priority to time-sensitive applications Built into a variety of hardware and software products such as Cisco and Microsoft

38. Continued You can Classify different types of traffic (video, audio, data) Prioritize mission-critical and time-sensitive traffic Load balance across multiple resources for redundancy and performance.

39. Voice and Data Convergence Voice Over Internet Protocol (VoIP) Pros Administer and manage one infrastructure Handsets in any location Not really occurring any additional costs Telecommunters use laptops for telephone service Data integration

40. Cons VoIP relatively new technology Audio-quality problems Interruption of service with network Software upgrades for handheld devices Service in the event of power outage Latency Voice people need to learn about network

41. Summary Slide OSI Model Internet Protocol Suite IP Addressing Local Area Networks Wide Area Networks Remote Access Network Management Voice and Data Convergence