Módulo:

Fundamentos de Redes

Maestría en Seguridad

Telemática

Facilitador Diego Avila Pesántez Estudios:

Ingeniero en Sistemas Informáticos ( UC 1997)

Maestría en Internetworking (U. de Chile 2002)

Diplomado en Docencia Universitaria (2000)

Maestría en Informática Aplicada (ESPOCH

2003)

Estudiante del Doctorado en Ingeniería en

Sistemas e Informática. UMNSM

Certificaciones Internacionales:

CCNA (Cisco Certified Netwok Associete)

CCNP(Cisco Certified Network Proffesional)

Motivación

http://www.youtube.com/watch?v=itIy8jlVF6o

Evaluación del Módulo

• Tareas/Labs 50%

• Caso de estudio 50%

Horario de jornadas:

Viernes 17h00 - 22h00

Sábado 08h00 - 17h00

Agenda

• Conceptos Generales, modelo OSI

& TCP/IP

• Conectividad en función de

capas: Física, Enlace de datos, Red

• Tecnologías de Redes LAN

•Direccionamiento IPv4, IPv6.

Objetivos del Módulo •Revisar la tecnología actual del entorno de

redes que permita a los asistentes recordar

definiciones y conceptos importantes como

punto de partida a los laboratorios

experimentales.

• Analizar los principios del Modelo de

referencia OSI, TCP/IP, switching Ethernet,

protocolos capa 3 que permitan comparar con

las diferentes aplicaciones y su funcionamiento

estratificado en capas.

Bibliografía · Isaacs, M. Internet User's Guide to Network Resource Tools:

http://www.terena.nl/gnrt/. Estupenda guía sobre las herramientas y servicios de

Internet. Imprescindible para cualquier usuario habitual u ocasional.

· McKeon, B. An Introduction to the OSI Reference Model:

http://ntrg.cs.tcd.ie/undergrad/4ba2/ . Muy buen resumen del modelo OSI y de los

protocolos OSI. También habla de TCP/IP y ATM.

· Networking Essentials: http://www.labmice.net/networking/networkbasics.htm

· Technology Guides for Communications & Networking:

http://www.techguide.com/. Interesante recopilación de guías técnicas. Hay que

registrarse para conseguirlas, pero es gratis.

· Home Page de Raj Jain: http://www.cis.ohio-state.edu/~jain/. Impresionante

colección de materiales docentes sobre redes (presentaciones, ejercicios, etc.)

· Tutoriales de Network Magazine:

http://www.networkmagazine.com/static/tutorial/index.html. Interesante

recopilación de artículos educativos sobre diversos temas relacionados con redes

de computadores.

Bibliografía Howe, D. Free On-Line Dictionary Of Computing: http://wombat.doc.ic.ac.uk/.

Recopilación exhaustiva de términos informáticos.

· Malkin, G. (RFC1983). Internet Users' Glossary. Completo diccionario de

términos y abreviaturas del mundo Internet

· Tech Encyclopedia: http://www.techweb.com/encyclopedia/

· Webopedia: http://webopedia.internet.com/

· Whatis: http://whatis.com/

ANSI (American National Standards Institute): http://www.ansi.org/

· ATM Forum: http://www.atmforum.com

· Frame Relay Forum: http://www.frforum.com

· IEEE (Institute of Electrical and Electronic Engineers): http://www.ieee.org

· IETF (Internet Engineering Task Force): http://www.ietf.org

9

Local Area Network (LAN)

Local Area Network (LAN)

An individual network usually spans a single

geographical area, providing services and applications

to people within a common organizational structure,

such as a single business, campus or region.

10

Wide Area Network (WAN)

Wide Area Networks (WANs)

Leased connections through a telecommunications

service provider network.

Networks that connect LANs in geographically

separated locations

Telecommunications service provider (Carrier)

interconnect the LANs at the different locations.

Voice and data on separate networks or converged

networks

T1, DS3, OC3

PPP, HDLC

Frame Relay, ATM

ISDN, POTS

11

End devices

End devices or hosts:

The source or destination of a message.

12

Components of the Network

Devices (hardware)

End devices, switch, router, firewall

Media (wired, wireless)

Cables, wireless mediums

Services (software)

Network applications, routing protocols, processes, algorithms

13

Servers and Clients

A host

Client, Server, or both.

Software determines the role.

Servers provide information and services to clients

e-mail or web pages

Clients request information from the server.

Server

Client

14

Network

Media

Network media: The medium over which the message

travels.

Cooper wires - electrical impulses.

Fiber optics – pulses of light

Wireless – electromagnetic waves.

15

Network

Media

Different media considerations (4):

Distance it will carry signal

Environment it works in

Bandwidth (speed)

Cost

Components of a Network

Topology Diagrams

New Network Trends

Some of the top trends include:

Bring Your Own Device (BYOD)

Online collaboration

Video

Cloud computing

Network Trends

Bring Your Own Device (BYOD)

The concept of any device, to any content, in anyway is a major

global trend that requires significant changes to the way devices

are used. This trend is known as Bring Your Own Device (BYOD).

Online Collaboration

Video Communication

Cloud Computing

Cloud computing offers the following potential

benefits:

Organizational flexibility

Agility and rapid deployment

Reduced cost of infrastructure

Refocus of IT resources

Creation of new business

models

Data Centers A data center is a facility used to house computer

systems and associated components including:

Redundant data communications connections

High-speed virtual servers (sometimes referred to as

server farms or server clusters)

Redundant storage systems (typically uses SAN

technology)

Redundant or backup power supplies

Environmental controls (e.g., air conditioning, fire

suppression)

Security devices

Networking Technologies for the Home

Technology Trends in the Home

Networking Technologies for the Home

Powerline Networking

Networking Technologies for the Home

Wireless Broadband

Network Security

Network Security

Security Threats

The most common external threats to networks

include:

Viruses, worms, and Trojan horses

Spyware and adware

Zero-day attacks, also called zero-hour attacks

Hacker attacks

Denial of service (DoS) attacks

Data interception and theft

Identity theft

Security Solutions Network security components often include:

Antivirus and antispyware

Firewall filtering

Dedicated firewall systems

Access control lists (ACL)

Intrusion prevention systems (IPS)

Virtual Private Networks (VPNs)

29

Early days – proprietary network equipment and protocols.

Now – Industry standards

Institute of Electrical and Electronics Engineers (IEEE)

Examples: 802.3 (Ethernet), 802.11 (WLAN)

Internet Engineering Task Force (IETF)

Internet standards

RFCs (Request for Comments)

Example: TCP, IP, HTTP, FTP

Protocol Suites and Standards

30

Example: RFC 791 IPv4

31

Protocols

Protocol – Rules that govern communications.

Protocol suite - A group of inter-related protocols

Example: TCP/IP

HTTP

Header Data

Frame Header IP Header TCP Header App

Header Frame Trailer

Protocols

32

Protocol and Reference Models

The Open Systems Interconnection (OSI) model is the most widely known internetwork reference model.

The International Organization for Standardization (ISO) released the OSI reference model in 1984, was the descriptive scheme they created.

33

TCP/IP Model

TCP/IP Model and Protocol Suite is an open standard.

34

Multiple protocols (encapsulated)

Encapsulation – Process of adding a header to the data

or any previous set of headers.

Decapsulation – Process of removing a header.

HTTP

Header Data

Frame Header IP Header TCP Header App

Header Frame Trailer

Data

Protocols

35

The Communication Process - Encapsulation

Server

Data HTTP

Header

TCP

Header

IP

Header

Data Link

Header

Data Link

Trailer

HTTP Data

Encapsulation – Process of adding control information as

it passes down through the layered model.

36

The Communication Process - Decapsulation

Data HTTP

Header

TCP

Header

IP

Header

Data Link

Header

Data Link

Trailer

Client

HTTP Data

Decapsulation – Process of removing control information

as it passes upwards through the layered model.

37

The

Communication

Process

Protocol Data Unit (PDU) - The form that a piece of data takes at any layer.

PDUs are named according to the protocols of the TCP/IP suite.

Data - Application layer PDU

Segment - Transport Layer PDU

Packet - Internetwork Layer PDU

Frame - Network Access Layer PDU

Bits - A PDU used when physically transmitting data over the medium

TAREA EN CLASE: ENCAPSULAMIENTO

Organizarse en equipos de 4 personas.

Determinar la manera como pueden

describir el proceso de encapsulamiento

de datos.

10 min. para planificar la presentación.

39

Warriors of the Net

To get an idea of many of the things we will be learning about…

TCP-IP Protocol

TCP-IP Protocol

42

HTTP

(WWW)

FTP

SMTP

(email)

Telnet

(file transfer)

(remote login)

DHCP

(IP address

resolution)

DNS

(file sharing)

P2P

(domain name

resolution)

(file sharing)

SMB

We will examine

HTTP in detail.

Aplication Layer

43

HTTP (HyperText Transfer Protocol)

Implemented in:

Client program

Server program

Web page (also called a html document)

Web page consists of objects

HTML file

JPEG image

JAVA applet

Audio file

HTTP

Server

HTTP

Client

HTTP HTTP

44

HTTPS

HTTPS (Hypertext Transfer Protocol over Secure Socket Layer) is a URL

scheme used to indicate a secure HTTP connection.

HTTPS is not a separate protocol

combination of a normal HTTP interaction over an encrypted:

Secure Sockets Layer (SSL) or

Transport Layer Security (TLS) connection

45

FTP (File Transfer Protocol)

FTP was developed to allow for file transfers between a client and a server.

Used to push and pull files from a server running the FTP daemon (FTPd).

RFC 959

FTP

Client FTP

Server

46

Internet mail involves:

User agents

Allows users to read, reply, compose, forward, save, etc., mail messages

GUI user agents: Outlook, Eudora, Messenger

Text user agents: mail, pine, elm

Mail servers

Stores user mail boxes, communicates with local user agents and other

mail servers.

SMTP

Principle application layer protocol for Internet mail

Sent over TCP

Mail access protocols: POP3, IMAP4, HTTP

SMTP SMTP

POP3

IMAP

User agent User agent Mail server Mail server

SMTP – Simple Mail Transfer Protocol

47

Telnet

Allows a user to remotely access another device (host, router,

switch).

Connection called a Virtual Terminal (VTY) session.

Telnet clients:

Putty

Teraterm

Hyperterm

Server

Telnet Telnet

48

Telnet

Supports user authentication,

Does not encrypt data.

Secure Shell (SSH) protocol offers an alternate and secure method for

server access.

Stronger authentication

Encrypts data

49

DHCP – Dynamic Host Configuration Protocol

IP addresses and other information can be obtained:

Statically

Dynamically (DHCP)

50

DNS – Domain Name System

DNS allows users (software) to use domain names instead of IP addresses

Transport Layer Protocols

52

0 15 16 31

16-bit Source Port Number

16-bit Destination Port Number

32-bit Sequence Number

32 bit Acknowledgement Number

4-bit Header

Length

6-bit

(Reserved)

U

R

G

A

C

K

P

S

H

R

S

T

S

Y

N

F

I

N

16-bit Window Size

16-bit TCP Checksum

16-bit Urgent Pointer

Options (if any)

Data (if any)

UDP and TCP TCP

TCP provides:

Reliable delivery

Error checking

Flow control

Congestion control

Ordered delivery

(Connection establishment)

UDP provides:

Unreliable delivery

No error checking

No flow control

No congestion control

No ordered delivery

(No connection establishment)

UDP

53

TCP Header

TCP provides reliable delivery on top of unreliable IP

0 15 16 31

16-bit Source Port Number

16-bit Destination Port Number

32-bit Sequence Number

32 bit Acknowledgement Number

4-bit Header

Length

6-bit

(Reserved)

U

R

G

A

C

K

P

S

H

R

S

T

S

Y

N

F

I

N

16-bit Window Size

16-bit TCP Checksum

16-bit Urgent Pointer

Options (if any)

Data (if any)

54

TCP Header

source port -- the number of the calling port

destination port -- the number of the called port

sequence number -- the number used to ensure correct sequencing of the arriving data

acknowledgment number -- the next expected TCP octet

HLEN -- the number of 32-bit words in the header

reserved -- set to 0

code bits -- the control functions (e.g. setup and termination of a session)

window -- the number of octets that the sender is willing to accept

checksum -- the calculated checksum of the header and data fields

urgent pointer -- indicates the end of the urgent data

option -- one currently defined: maximum TCP segment size

data -- upper-layer protocol data

55

TCP: Connection Establishment 0 15 16 31

16-bit Source Port Number

16-bit Destination Port Number

32-bit Sequence Number

32 bit Acknowledgement Number

4-bit Header

Length

6-bit

(Reserved)

U

R

G

A

C

K

P

S

H

R

S

T

S

Y

N

F

I

N

16-bit Window Size

16-bit TCP Checksum

16-bit Urgent Pointer

Options (if any)

Data (if any)

Three-way

Handshake

56

TCP: Connection Termination

1. When the client has no more data to send in the stream, it sends a segment

with the FIN flag set.

2. The server sends an ACK to acknowledge the receipt of the FIN to terminate

the session from client to server.

3. The server sends a FIN to the client, to terminate the server to client session.

4. The client responds with an ACK to acknowledge the FIN from the server.

57

UDP

source port -- the number of the calling port

destination port -- the number of the called port

UDP length -- the length of the UDP header

checksum -- the calculated checksum of the header and data fields

data -- upper-layer protocol data

0 15 16 31

16-bit Source Port Number

16-bit Destination Port Number

16-bit UDP Length

16-bit UDP Checksum

Data (if any)

58

UDP

Why would an application developer choose UDP rather than TCP?

Finer application-layer control

TCP will continue to resend segments that are not acknowledged.

Applications that use UDP can tolerate some data loss:

Streaming video

VoIP (Voice over IP)

Application decides whether or not to resend entire file: TFTP

0 15 16 31

16-bit Source Port Number

16-bit Destination Port Number

16-bit UDP Length

16-bit UDP Checksum

Data (if any)

Time

Client Server

59

Network Layer

IPv4

IPv6

60

Network Layer

Layer 3 uses four basic processes:

Addressing

Encapsulation

Routing

Decapsulation

0 15 16 31

4-bit

Version

4-bit

Header

Length

8-bit Type Of

Service

(TOS)

16-bit Total Length (in bytes)

16-bit Identification

3-bit

Flags

13-bit Fragment Offset

8 bit Time To Live

TTL

8-bit Protocol

16-bit Header Checksum

32-bit Source IP Address

32-bit Destination IP Address

Options (if any)

Data

Assignment of IP Addresses

Regional Internet Registries (RIRs)

62

IP Header IPv4

IP Destination Address

32-bit binary value that represents the packet destination

Network layer host address.

IP Source Address

32-bit binary value that represents the packet source Network

layer host address.

Where I am

going.

Where I came

from.

63

Sending hosts generates the value for TTL.

Common operating system TTL values are:

UNIX: 255

Linux: 64 or 255 depending upon vendor and version

Microsoft Windows 95: 32

Microsoft Vista: 128

Protocol field enables the Network layer to pass the data to the

appropriate upper-layer protocol.

Example values are:

01 ICMP, 06 TCP, 17 UDP

Type-of-Service is used to determine the priority of each packet.

Enables Quality-of-Service (QoS) mechanism for high priority traffic.

What types of traffic might a network administrator need to give priority

to? Traffic that cannot accept any delays.

VoIP, Streaming video

IP Header IPv4

Special Use IPv4 Addresses

Network and Broadcast addresses – within each

network the first and last addresses cannot be assigned

to hosts

Loopback address – 127.0.0.1 a special address that

hosts use to direct traffic to themselves (addresses

127.0.0.0 to 127.255.255.255 are reserved)

Link-Local address – 169.254.0.0 to 169.254.255.255

(169.254.0.0/16) addresses can be automatically

assigned to the local host

Experimental addresses – 240.0.0.0 to

255.255.255.254 are listed as reserved

Public and Private IPv4 Addresses

Private address blocks are:

Hosts that do not require access to the Internet can use private

addresses

10.0.0.0 to 10.255.255.255 (10.0.0.0/8)

172.16.0.0 to 172.31.255.255 (172.16.0.0/12)

192.168.0.0 to 192.168.255.255 (192.168.0.0/16)

Shared address space addresses:

Not globally routable

Intended only for use in service provider networks

Address block is 100.64.0.0/10

Public and Private IPv4 Addresses

Private address blocks are:

Hosts that do not require access to the Internet can use

private addresses

10.0.0.0 to 10.255.255.255 (10.0.0.0/8)

172.16.0.0 to 172.31.255.255 (172.16.0.0/12)

192.168.0.0 to 192.168.255.255 (192.168.0.0/16)

Shared address space addresses:

Not globally routable

Intended only for use in service provider networks

67

Network/Subnets Address

Networks can be subdivided into subnets.

This provides for several benefits which we will discuss later.

Networks can be grouped based on factors that include:

Geographic location, Purpose, Ownership

172.16.10.100/24

172.16.10.55/24

172.16.10.3/24

172.16.20.77/24

172.16.20.96/24

172.16.20.103/24

172.16.30.39/24

172.16.30.10/24

172.16.30.111/24

172.16.40.123/24

172.16.40.51/24

172.16.40.29/24 172.16.1.1/24

172.16.10.1/24 172.16.20.1/24 172.16.30.1/24 172.16.40.1/24

172.16.10.0/24 172.16.20.0/24 172.16.30.0/24 172.16.40.0/24

68

Static routes

Manually entered by the administrator

Dynamic Routing protocols

Routers automatically learn about remote networks

Ex: RIP, EIGRP, OSPF, IS-IS, BGP

192.168.1.254/24

C 192.168.2.0/24 is direction connected, FastEthernet0/1

Network 192.168.2.0/24

Network 192.168.1.0/24

Routing

IPv6 Addressing

128-bit hexadecimal format (0-9, A-F)

Uses 16-bit hexadecimal number fields separated by

colons (:)

Every 4-hexadecimal digits are equivalent to 16-bits.

Consists of 8 hextets/quartets which is the equivalent to 16-

bits per-hextet.

2001:0DB8:0001:5270:0127:00AB:CAFE:0E1F /64

- 2001 in hexadecimal is 0010 0000 0000 0001 in

binary

IPv6 Addressing Structure

The Site Prefix or Global Routing Prefix is the first 3

hextets or 48-bits of the address. It is assigned by the

service provider.

The Site Topology or Subnet ID Is the 4th hextet of the

address.

The Interface ID is the last 4 hextets or 64-bits of the

address. It can be manually or dynamically assigned using

the EUI-64 command. (Extended Unique Identifier)

IPv6 Addressing Structure

First 3 bits are fixed at 001 or 200::/12 (IANA Global

Routing Number)

Bits 16-24 identifies the Regional Registry:

- AfriNIC, APNIC, LACNIC, RIPE NCC and ARIN

2001:0000::/23 – IANA

2001:0200::/23 – APNIC (Asia/Pacific Region)

2001:0400::/23 – ARIN (North America Region)

2001:0600::/23 – RIPE (Europe, Middle East and Central Asia)

IPv6 Addressing Structure

Remaining 8-bits up to /32 identifies the ISP.

The 3rd hextet represents the Site/Customer Identifier.

The 4th hextet represent the Site Topology/Subnet ID.

- Allows 65,536 subnets with 18,446,744,073,709,551,616 (18

quintillion) for each subnet.

- Not part of the host address field.

IPv6 Addressing Scheme and Subnets

The Interface ID are the remaining 64-bits of the address.

Can be manually configured or dynamically by using the EUI-64

(Extended Unique Identifier).

The EUI-64 command uses the device 48-bits MAC Address and

convert it into 64-bits by adding FF:FE in the middle of the address.

The first (network) and last (broadcast) address may be assigned to an

interface. An interface may contain more than one IPv6 address.

There are no broadcast addresses, multicast is used instead.

IPv6 Addressing Scheme and Subnets

IPv6 uses the same method as IPv4 to subnet their

addresses.

/127 gives you 2 addresses.

/124 gives you 16 addresses

/120 gives you 256 addresses

The first address in a network consists of all 0's and the last

address consists of all F's.

It’s recommended for simplicity and design purposes to use

/64 everywhere. Using anything less than /64 could

potentially break IPv6 features and cause increased design

complexity.

Leading Zeroes and Double Colons (::)

Leading 0s (zeroes) in any 16-bit section can be omitted.

Address before omission:

2001:0DB8:0001:5270:0127:00AB:CAFE:0E1F /64

Address after omission:

2001:DB8:1:5270:127:AB:CAFE:E1F /64

This rule applies only to leading 0s; if trailing 0s are omitted, the

address would be vague.

Leading Zeroes and Double Colons (::)

A Double Colons or Compressing Zeroes can be used to shorten an

IPv6 address when one or more hextets consist of all 0s.

Double Colons can only be used to compress a single contiguous 16-

bits blocks. You cannot use double colons to include part of a block.

Double Colons can only be used once in an address, if it's used more

than once the address could be ambiguous

77

Data Link Layer

Data Link layer

Connects the Network Layer with the Physical Layer

Network Layer and above is software (IP, TCP, HTTP, etc.)

Physical layer is implemented in hardware (converting bits to a transmission signal)

Data Link layer is implemented in both:

Software

Hardware

Data Link Layer prepares Network Layer packets for transmission across some form of media, be it copper, fiber, or the atmosphere.

78

Data Link Sublayers

Data Link layer has two sublayers (sometimes):

Logical Link Control (LLC) – Software processes that provide

services to the Network layer protocols.

Frame information that identifies the Network layer protocol.

Multiple Layer 3 protocols, (IP and IPX) can use the same

network interface and media.

Media Access Control (MAC) - Media access processes

performed by the hardware.

Provides Data Link layer addressing and framing of the data

according to the protocol in use.

79

Media Access Control

The media access control methods used by logical

multi-access topologies are typically:

CSMA/CD - Hubs

CSMA/CA - Wireless

Token passing – Token Ring

Physical Layer Protocols & Services

Describe the purpose of the Physical layer in the network and

identify the basic elements that enable this layer to fulfill its

function

Physical Layer Protocols & Services

Describe the role of bits in representing a frame as it is

transported across the local media

Physical Layer Protocols & Services

Describe the role of signaling in the physical media

Physical Layer Protocols & Services

Identify hardware components associated with the Physical layer

that are governed by standards

Characteristics & Uses of Network Media

Coaxial Cable

Coaxial Cable

Advantages:

Less expensive than fiber

It has been used for many years for many types of data communication, including cable television

Disadvantages:

More expensive and more difficult to install than twisted pair

Needs more room in wiring ducts than twisted pair

Shielded Twisted Pair (STP and ScTP)

Shielded twisted-pair cable (STP) combines the techniques of shielding, cancellation, and twisting of wires.

Each pair of wires is wrapped in metallic foil.

The four pairs of wires are wrapped in an overall metallic braid or foil.

A new hybrid of UTP with traditional STP is Screened UTP (ScTP), also known as Foil Twisted Pair (FTP).

ScTP is essentially UTP wrapped in a metallic foil shield, or screen.

STP – Shielded Twisted Pair ScTP – Screened Twisted Pair

Shielded Twisted Pair (STP and ScTP)

Greater protection from all types of external and internal interference than UTP.

Reduces electrical noise within the cable such as pair to pair coupling and crosstalk.

Reduces electronic noise from outside the cable, for example electromagnetic interference (EMI) and radio frequency interference (RFI).

More expensive and difficult to install than UTP.

Needs to be grounded at both ends

Characteristics & Uses of Network Media

Unshielded twisted-pair cable (UTP) is a four-pair wire medium used in

a variety of networks.

TIA/EIA-568-B contains specifications governing cable performance.

RJ-45 connector

When communication occurs, the signal that is transmitted by the

source needs to be understood by the destination.

Characteristics & Uses of Network Media

ST and SC Connectors

The type of connector most commonly used with multimode

fiber is the Subscriber Connector (SC connector).

On single-mode fiber, the Straight Tip (ST) connector is

frequently used.

LC (Little conector).

Fiber versus Copper

Implementation Issues Copper Media Fibre Optic

Bandwidth Supported 10 Mbps – 10 Gbps 10 Mbps – 100 Gbps

Distance Relatively short

(1 – 100 meters)

Relatively High

(1 – 100,000 meters)

Immunity To EMI And RFI Low High

(Completely immune)

Immunity To Electrical Hazards Low High

(Completely immune)

Media And Connector Costs Lowest Highest

Installation Skills Required Lowest Highest

Safety Precautions Lowest Highest

Properties of Wireless Media

Wireless does have some areas of concern including:

Coverage area

Interference

Security

• IEEE 802.11 standards

• Commonly referred to as Wi-Fi.

• Uses CSMA/CA

• Variations include:

• 802.11a: 54 Mbps, 5 GHz

• 802.11b: 11 Mbps, 2.4 GHz

• 802.11g: 54 Mbps, 2.4 GHz

• 802.11n: 600 Mbps, 2.4 and 5 GHz

• 802.11ac: 1 Gbps, 5 GHz

• 802.11ad: 7 Gbps, 2.4 GHz, 5 GHz, and 60 GHz

• IEEE 802.15 standard

• Supports speeds up to 3 Mb/s

• Provides device pairing over distances from 1 to 100

meters.

• IEEE 802.16 standard

• Provides speeds up to 1 Gbps

• Uses a point-to-multipoint topology to provide

wireless broadband access.

Wireless Media

Types of Wireless Media

Wireless Media

Wireless LAN

Cisco Linksys EA6500 802.11ac Wireless Router

Wireless Media

802.11 Wi-Fi Standards

Standard Maximum

Speed Frequency

Backwards

Compatible

802.11a 54 Mbps 5 GHz No

802.11b 11 Mbps 2.4 GHz No

802.11g 54 Mbps 2.4 GHz 802.11b

802.11n 600 Mbps 2.4 GHz or 5 GHz 802.11b/g

802.11ac 1.3 Gbps

(1300 Mbps)

2.4 GHz and 5.5

GHz 802.11b/g/n

802.11ad 7 Gbps

(7000 Mbps)

2.4 GHz, 5 GHz and

60 GHz 802.11b/g/n/ac

How wireless LANs communicate

Since radio frequency (RF) is a

shared medium, collisions can

occur just as they do on wired

shared medium.

The major difference is that there is

no method by which the source

node is able to detect that a

collision occurred.

For that reason WLANs use Carrier

Sense Multiple Access/Collision

Avoidance (CSMA/CA).

This is somewhat like Ethernet

CSMA/CD.

Tarea Extraclase:

Realizar un mapa mental sobre características de cables: UTP/STP Cat 5e, Cat 6, Cat 6A, Cat 7, Fibra óptica multimodo, Fibra óptica monomodo.

Stack de protocolos que utiliza la aplicación VoIP utilizando Wireshark.

Simulación de la red de Campus utilizando el Packet Tracer de Cisco.