40-subcapa acceso al medio

8/14/2019 40-Subcapa Acceso Al Medio

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Asignacin Dinmica de Canalesen LANs y MANs

Asignacin Dinmica de Canalesen LANs y MANs

Modelo de Estacin.

Suposicin de canal nico.

Suposicin de colisiones

(a) Continuous Time.(b) Slotted Time.

(a) Carrier Sense.

(b) No Carrier Sense.


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Protocolos de Acceso MltipleProtocolos de Acceso Mltiple

ALOHA

Carrier Sense Multiple Access Protocols

Collision-Free Protocols

Limited-Contention Protocols

Wavelength Division Multiple AccessProtocols

Wireless LAN Protocols


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Pure ALOHAPure ALOHA

ALOHA puro, tramas transmitidas en tiempos arbitrarios.


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Pure ALOHA (2)Pure ALOHA (2)

Perodo de vulnerabilidad para la trama roja ( t0+ 2 t )


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Pure ALOHA (3)Pure ALOHA (3)


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CSMA Persistente yNopersistente

CSMA Persistente yNopersistente


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CSMA con Deteccin deColisiones

CSMA con Deteccin deColisiones

CSMA/CD puede estar en los estados:

contencin, transmisin, o libre.


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Collision-Free ProtocolsCollision-Free Protocols

bit-map protocol.


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Collision-Free Protocols (2)Collision-Free Protocols (2)

Binary countdown protocol.

- indica silencio.


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Limited-Contention ProtocolsLimited-Contention Protocols

Acquisition probability for a symmetriccontention channel.


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Adaptive Tree Walk ProtocolAdaptive Tree Walk Protocol

Arbol para 8 estaciones.


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Wavelength Division Multiple AccessProtocols (WDMA)

Wavelength Division Multiple AccessProtocols (WDMA)

Wavelength division multiple access.


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Wireless LAN ProtocolsWireless LAN Protocols

Wireless LAN.

(a) A transmitiendo. (b) B transmitiendo


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Wireless LAN Protocols (2)Wireless LAN Protocols (2)

MACA protocol.

(a) A enviando un RTS a B.

(b) B respondiendo con CTS to A.


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EthernetEthernet

Cableado Ethernet

Manchester Encoding

Ethernet MAC Sublayer Protocol

Algoritmo Binary Exponential Backoff

Ethernet Performance

Switched Ethernet

Fast Ethernet

Gigabit Ethernet

IEEE 802.2: Logical Link Control

Retrospectiva de Ethernet


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Cableado EthernetCableado Ethernet


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Ethernet Cableado (2)Ethernet Cableado (2)

Three kinds of Ethernet cabling.(a) 10Base5, (b) 10Base2, (c) 10Base-T.


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Ethernet Cableado (3)Ethernet Cableado (3)

Topologias. (a) Lineal, (b) Spine,

(c) Arbol, (d) Segmentado.


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3-19

Codificacin EthernetCodificacin Ethernet

(a) Binary (b) Manchester(c) Differential Manchester

C SEth t MAC S bl


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Ethernet MAC SublayerProtocol

Ethernet MAC SublayerProtocol

Formato de tramas.

(a) DIX Ethernet, (b) IEEE 802.3.


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Ethernet PerformanceEthernet Performance

Eficiencia de Ethernet a 10 Mbps con

512-bit slot times.


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Switched EthernetSwitched Ethernet


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Fast EthernetFast Ethernet

Cableado original Fast Ethernet


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Gigabit EthernetGigabit Ethernet

(a) 2 Usuarios.

(b) Mltiples usuarios.


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Gigabit Ethernet (2)Gigabit Ethernet (2)

IEEE 802 2IEEE 802 2


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IEEE 802.2:Logical Link Control

IEEE 802.2:Logical Link Control

(a) Lugar de LLC.

(b) Formatos


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Wireless LANsWireless LANs

802.11 Protocol Stack

802.11 Capa fsica

802.11 MAC Sublayer Protocol

Estructura de trama 802.11

Servicios


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Stack de Protocolos 802.11Stack de Protocolos 802.11

P t l d b MACP t l d b MAC


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(a) Problema de estacin oculta.

(b) Problema de estacin expuesta

Protocolo de subcapa MAC802.11

Protocolo de subcapa MAC802.11



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Virtual channel sensing usandoCSMA/CA.

Protocolo de subcapa MAC802.11 (2)




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Fragment burst.





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Espacio Intertrama en 802.11.


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Estructura de Trama 802.11Estructura de Trama 802.11

Trama 802.11


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Servicios 802.11Servicios 802.11

Association

Disassociation

Reassociation

Distribution

Integration


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802.11 Servicios Intracelda802.11 Servicios Intracelda

Authentication

Deauthentication

Privacy

Data Delivery


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Broadband WirelessBroadband Wireless

802.11 y 802.16

802.16 Stack de Protocolos 802.16 Capa fisica

802.16 Protocolos subcapa MAC

802.16 Estructura de Trama


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Stack de Protocolos 802.16Stack de Protocolos 802.16


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Capa Fisica 802.16Capa Fisica 802.16


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802.16 Capa Fisica (2)802.16 Capa Fisica (2)

Tramas y time slotsPara time division duplexing.


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Estructura de trama 802.16Estructura de trama 802.16

(a) Trama genrica. (b) Tramabandwidth request .


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BluetoothBluetooth

Arquitectura Bluetooth

Aplicaciones Bluetooth

Bluetooth Protocol Stack

Bluetooth Radio Layer

Bluetooth Baseband Layer

Bluetooth L2CAP Layer

Estructura de Trama Bluetooth


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Arquitectura BluetoothArquitectura Bluetooth

Two piconets can be connected toform a scatternet.


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Applicaciones BluetoothApplicaciones Bluetooth


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Estructura de Trama BluetoothEstructura de Trama Bluetooth


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Data Link Layer SwitchingData Link Layer Switching

Bridges 802.x a 802.y

Local Internetworking

Spanning Tree Bridges

Remote Bridges

Repeaters, Hubs, Bridges, Switches,Routers, Gateways

Virtual LANs


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Data Link Layer SwitchingData Link Layer Switching


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Bridges 802.x a 802.yBridges 802.x a 802.y


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Bridges 802.x a 802.y (2)Bridges 802.x a 802.y (2)


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Local InternetworkingLocal Internetworking


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Spanning Tree BridgesSpanning Tree Bridges


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Spanning Tree Bridges (2)Spanning Tree Bridges (2)


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Remote BridgesRemote Bridges

Repeaters Hubs BridgesRepeaters Hubs Bridges


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Repeaters, Hubs, Bridges,Switches, Routers y Gateways

Repeaters, Hubs, Bridges,Switches, Routers y Gateways

(a) Dispositivos y capas.

(b) Frames, packets, y headers.

Repeaters Hubs Bridges SwitchesRepeaters Hubs Bridges Switches


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Repeaters, Hubs, Bridges, Switches,Routers y Gateways (2)

Repeaters, Hubs, Bridges, Switches,Routers y Gateways (2)

(a) hub. (b) bridge. (c) switch.

Vi t l LANVi t l LAN


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Virtual LANsVirtual LANs

A building with centralized wiring using

hubs and a switch.

Vi t l LAN (2)Vi t l LAN (2)


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Virtual LANs (2)Virtual LANs (2)

(a) Cuatro LANs organizadas en 2 VLANs, gris yblanca por 2 bridges. (b) Las mismas 15 maquinasorganizadas en 2 VLANs por switches.

IEEE 802 1Q St d dIEEE 802 1Q St d d


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IEEE 802.1Q StandardIEEE 802.1Q Standard

Transition from legacy Ethernet to VLAN-aware Ethernet. The shaded symbols are

VLAN aware. The empty ones are not.

IEEE 802 1Q St d d (2)IEEE 802 1Q St d d (2)


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IEEE 802.1Q Standard (2)IEEE 802.1Q Standard (2)

RESUMENRESUMEN


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RESUMENRESUMEN

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