Network Design. Yiannos Mylonas

Transcription

1 Network Design Yiannos Mylonas

2 Physical Topologies There are two parts to the topology definition: the physical topology, which is the actual layout of the wire (media), and the logical topology, which defines how data flows through the network.

3 Media Cable length Cost Ease of installation

4 Copper Media

5 UTP (Unshielded Twisted Pair)

6 STP (Shielded twisted Pair)

7 UTP vs. STP UTP Does not include shielding around its conductors. Typically contains four pairs of stranded or solid conductors. Inexpensive and reliable. Supports distances of up to 100 meters. Supports data transfer rates up to 1Gbps. STP Includes shielding, typically a foil wrapper, around its conductors to improve the cable s resistance to interference and noise. Typically contains four pairs of stranded or solid conductors. Supports up to 100 meters. More expensive than UTP.

8 UTP Categories Category Network Type and Maximum speed 1 Voice grade; not suitable for networking. 2 Digital telephone and low speed networks. Maximum speed:4 Mbps 3 Ethernet. Maximum speed: 10 Mbps with possible bandwidth of 16MHz. CAT 3 is currently used for telephone wiring. 4 IBM Token Ring. Maximum speed: 16 Mbps; may also be used for 10 Mbps Ethernet. 5 & 5e Category 5: Fast Ethernet. Supports a signaling rate of 100Mbps. Category 5e: Gigabit Ethernet. Supports a signaling rate of 350Mbps. 6 Gigabit Ethernet. Maximum speed: 1 Gbps. Supports a signaling rate of 250 MHz. 7 Gigabit Ethernet. Maximum speed: 1 Gbps+. Supports a signaling rate of 1 GHz.

9 Coaxial Connectors

10 Twisted Pair Connectors RJ 45 jack Front View

11 Fiber Optic

12 Fiber Optic Cable Mode Types Mode Type Single mode fiber Step index multimode fiber Graded index multimode fiber Description Carries a single optical signal. Has a small core, which allows only a single beam of light to pass. A laser, usually operating in the infrared portion of the spectrum, is modulated in amplitude to transmit the signal though the fiber. Contains a core surrounded by cladding, each with its own uniform index of refraction. When light from the core enters the cladding, a step down occurs due to the difference in the refractive indices. Step index fiber uses total internal reflection to trap light. Possesses variations in the core glass to compensate for the mode path length difference. Provided up to 2GHz of bandwidth, which is significantly more than step index fiber.

13 Fiber connectors

14 Cable Type Properties Cable Type Coaxial Fiber Optic Properties Transmission speed: 10 Mbps Distance: Star topology, 6000 meters. Bus topology 3000 meters. Duplex: Supports both half duplex and full duplex transmissions. Noise Immunity: High Frequency: 1GHz to 10 GHz Transmission speed: Mbps Distance: Multimode fiber is typically used for shorter runs of up to about 500 meters, and single mode for longer runs. The ultra high quality of some fiber cables allows runs of 100 km or more between repeaters. Duplex: Consist of two fibers found in a side by side zip cord used for simultaneous, bi directional data transfer. Noise Immunity: Superior Frequency: Very High Twisted Pair Transmission speed: CAT 3: UTP at 10 Mbps CAT 5: up to 100 Mbps CAT 6: up to 155 Mbps Distance: 540 meters Duplex: full Capacity Noise Immunity: 30 MHz Frequency: Up to 600 MHz.

15 Repeater

16 HUBs A hub is a networking device used to connect the nodes in a physical star topology network into a logical bus topology. Two common types of hubs are passive and active. A passive hub simply receives data transmitted from a device to one port and broadcasts it out to the devices connected on all other ports. An active hub performs the same receive then broadcast action as a passive hub, and also regenerates or boosts the signal much like a repeater. Hubs are generally inexpensive and easy to manage; however, they have a high degree of contention due to all ports being in the same contention domain and therefore do not provide the best performance in high traffic or latency sensitive situations.

17 Switch A switch is a networking device used to connect the drops in a physical star topology network into a logical bus topology. Switches work with pairs of ports, connecting two segments into an isolated contention domain as needed. Most switches can work with multiple pairs of ports simultaneously to improve performance. While the exact mechanisms switches use to perform their duty varies, the ultimate purpose of a switch is always to transport data from point A to point B in the fastest manner possible.

18 Bridge Reduce Traffic Improves Performance A bridge is a network device that divides a logical bus network into segments. Bridges examine the MAC address of each packet. If the packet is destined for a node connected to a different port, the bridge forwards the packet. If the packet is addressed to a node on its own segment, the bridge does not forward the packet. This arrangement reduces traffic between segments and improves overall network performance.

19 A router is a networking device that connects multiple networks that use the same protocol. Routers send data between networks by examining the network addresses contained in the packets they process. Router

20 Gateway Server A gateway is a device, software, or a system that converts data between incompatible systems. Gateways can translate data between different operating systems, between different formats, or between totally different networks.

21 Structure Cabling The Telecommunications Industry Association (TIA) and the Electronic Industries Association (EIA) developed the 568 Commercial Building Telecommunication Cabling standard. This standard defines the regulations on designing, building, and managing a cabling system that utilizes structured cabling according to specified performance characteristics to create a system of unified communications.

22 Wiring Distributions Components Subsystem Entrance facilities Backbone wiring Equipment room Telecommunication closet Horizontal wiring Work area Description Contains the telecommunication service entrance to the building. The demarcation point is usually 12 inches. Provides connections between equipment rooms and telecommunication closets. Provides the main connection point for an entire facility. Houses the connection equipment for cross connection to an equipment room along with workstations in the surrounding area. It contains horizontal wiring connections, and entrance facility connections. Runs from each workstation outlet to the telecommunication closet. The maximum allowed distance from the outlet to the closet is 295 feet. Four pair 100 ohm UTP cable Two fiber 62.5/125 mm fiber optic cable Multimode 50/125 mm multimode fiber optic cable. Consists of wallboxes and faceplates, connectors, and wiring used to connect work area equipment to the telecommunication closet.

23 Premise Wiring

24 TIA/EIA 568 A Horizontal Cabling Component

25 Horizontal Cabling System Structure

28 Premise Wiring Components Premise Wiring Component Drop Cable Patch panel Patch cable Cross connects Main distribution Frame (MDF) Intermediate distribution frame (IDF) Wiring closet Description The wire that runs to a PC, printer, or other device to the network. A connection point for drop and patch cables. Typically, a patch panel has one or more rows of RJ45 or other connectors. Drop cables are connected to the connectors. A cable that is plugged into the patch panel to connect two drops. A patch cable might or might not be a crossover cable, one in which the transmit conductor at one end is connected to the receive conductor at the other. Individual wires that connect two drops at a patch panel. Cross connects are rarely used in modern networks. A cable rack that interconnects the telecommunication wiring between itself and any number of IDFs. A cable rack that interconnects the telecommunication wiring between an MDF and any workstation devices. A small room in which patch panels are installed. Drop cables radiate out from the wiring closet to the components on the network.

29 Patch Panel

30 Wiring Crimpers

31 Punch Down Blocks A punch down block can be used to connect one group of telephone and network wires with another group in utility or telecommunication closets. They typically support lowbandwidth Ethernet and token ring networks.

32 Demarc Point

33 Sizing for Wiring Closets

34 Wiring Closets

35 Wiring Closets

36 Star Topology

37 Star Topology

38 Ethernet Star Topology

39 Network Topology

40

41 Floor Plan

42 Multi Story Building

43 Multi Building Campus

44 Network Documentation Network diagrams Device Information Configuration for each device and list of all devices. Utilization statistics Measure network performance Policies and Procedures

45 Physical Network diagram

46 Logical Network Diagram The logical network diagram documents the protocols and applications that control the flow of network traffic from one device to another. Items illustrated on a logical network diagram often include: The IP addresses of each network device. The FQDN of a device. The application type of each server (for example, mail server, file server, and so on). Any trust relationships that exist between nodes. The routing topology.

47 Plan for Disaster Recovery Network live Network recovery Network failures

48 Disaster Categories Natural Disaster Fires, floods Data destruction Data loss: virus attack, accidental deletion, natural disaster Equipment Failure Hardware failure

49 Disaster Recovery plan A disaster recovery plan is a policy and set of procedures that document how people and resources will be protected in case of disaster, and how the organization will recover from the disaster and restore normal functioning. The plan should be developed and implemented cooperatively among and between different functional groups.

50 Disaster Recovery Plan

51 The Network Reconstruction Plan

54 Hot, Warm, and Cold Sites

55 Maintain the Plan

56 Fault Tolerance Methods

57 Uninterruptible Power Supplies (UPS)

58 Partitions

59 Redundant Array of Independent disks (RAID)

60 RAID Level 0

61 RAID Level 1 Mirroring Duplexing

62 RAID Level 5

63 Link redundancy