Tema 1: Tecnologas de red. - PowerPoint PPT Presentation

Loading...

PPT – Tema 1: Tecnologas de red. PowerPoint presentation | free to download - id: 34f5e-NDBkO



Loading


The Adobe Flash plugin is needed to view this content

Get the plugin now

View by Category
About This Presentation
Title:

Tema 1: Tecnologas de red.

Description:

Transmisi n de Datos Multimedia - Master IC 2007/2008. 2 ... Documents cost SFr, but can get three freebies for each email address ... – PowerPoint PPT presentation

Number of Views:397
Avg rating:3.0/5.0
Slides: 97
Provided by: pman6
Learn more at: http://www.grc.upv.es
Category:

less

Write a Comment
User Comments (0)
Transcript and Presenter's Notes

Title: Tema 1: Tecnologas de red.


1
Tema 1 Tecnologías de red.
  • Estructura de Internet
  • Redes core
  • SONET
  • DWDM
  • Redes de acceso
  • Redes cableadas Ethernet et al.
  • Redes inalámbricas IEEE 802.11, UMTS et al.

2
Whats the Internet nuts and bolts view
  • End systems
  • Host computer
  • Network applications
  • Access networks
  • Local area networks
  • communication links
  • Network core
  • routers
  • network of networks

3
Internet structure network of networks
  • roughly hierarchical
  • at center tier-1 ISPs (e.g., MCI, Sprint,
    ATT, Cable and Wireless), national/international
    coverage
  • treat each other as equals

Tier 1 ISP
Tier 1 ISP
Tier 1 ISP
4
Tier-1 ISP e.g., Sprint
Sprint US backbone network
5
Internet structure network of networks
  • Tier-2 ISPs smaller (often regional) ISPs
  • Connect to one or more tier-1 ISPs, possibly
    other tier-2 ISPs

Tier 1 ISP
Tier 1 ISP
Tier 1 ISP
6
Internet structure network of networks
  • Tier-3 ISPs and local ISPs
  • last hop (access) network (closest to end
    systems)

Tier 1 ISP
Tier 1 ISP
Tier 1 ISP
7
Internet structure network of networks
  • a packet passes through many networks!

Tier 1 ISP
Tier 1 ISP
Tier 1 ISP
8
Network Access Points (NAPs)
Note Peers in this context are commercial
backbones..droh
Source Boardwatch.com
9
MCI/WorldCom/UUNET Global Backbone
Source www.lightreading.com
10
The situation in Europe
See http//www.geant2.net/server/show/nav.1368
11
Standards
  • Mandatory vs. voluntary
  • Allowed to use vs. likely to sell
  • Example health safety standards ?UL listing
    for electrical appliances, fire codes
  • Telecommunications and networking always focus of
    standardization
  • 1865 International Telegraph Union (ITU)
  • 1956 International Telephone and Telegraph
    Consultative Committee (CCITT)
  • Five major organizations
  • ITU for lower layers, multimedia collaboration
  • IEEE for LAN standards (802.x)
  • IETF for network, transport some applications
  • W3C for web-related technology (XML, SOAP)
  • ISO for media content (MPEG)

12
Who makes the rules? - ITU
  • ITU ITU-T (telecom standardization) ITU-R
    (radio) development
  • http//www.itu.int
  • 14 study groups
  • produce Recommendations
  • E overall network operation, telephone service
    (E.164)
  • G transmission system and media, digital systems
    and networks (G.711)
  • H audiovisual and multimedia systems (H.323)
  • I integrated services digital network (I.210)
    includes ATM
  • V data communications over the telephone network
    (V.24)
  • X Data networks and open system communications
  • Y Global information infrastructure and internet
    protocol aspects

13
ITU
  • Initially, national delegations
  • Members state, sector, associate
  • Membership fees (gt 10,500 SFr)
  • Now, mostly industry groups doing work
  • Initially, mostly (international) telephone
    services
  • Now, transition from circuit-switched to
    packet-switched universe lower network layers
    (optical)
  • Documents cost SFr, but can get three freebies
    for each email address

14
IETF
  • IETF (Internet Engineering Task Force)
  • see RFC 3233 (Defining the IETF)
  • Formed 1986, but earlier predecessor
    organizations (1979-)
  • RFCs date back to 1969
  • Initially, largely research organizations and
    universities, now mostly RD labs of equipment
    vendors and ISPs
  • International, but 2/3 United States
  • meetings every four months
  • about 300 companies participating in meetings
  • but Cisco, Ericsson, Lucent, Nokia, etc. send
    large delegations

15
IETF
  • Supposed to be engineering, i.e., translation of
    well-understood technology ? standards
  • make choices, ensure interoperability
  • reality often not so well defined
  • Most development work gets done in working groups
    (WGs)
  • specific task, then dissolved (but may last 10
    years)
  • typically, small clusters of authors, with large
    peanut gallery
  • open mailing list discussion for specific
    problems
  • interim meetings (1-2 days) and IETF meetings
    (few hours)
  • published as Internet Drafts (I-Ds)
  • anybody can publish draft-somebody-my-new-protocol
  • also official working group documents
    (draft-ietf-wg-)
  • versioned (e.g., draft-ietf-avt-rtp-10.txt)
  • automatically disappear (expire) after 6 months

16
IETF process
  • WG develops ? WG last call ? IETF last call ?
    approval (or not) by IESG ? publication as RFC
  • IESG (Internet Engineering Steering Group)
    consists of area directors they vote on
    proposals
  • areas applications, general, Internet,
    operations and management, routing, security,
    sub-IP, transport
  • Also, Internet Architecture Board (IAB)
  • provides architectural guidance
  • approves new working groups
  • process appeals

17
IETF activities
  • general (3) ipr, nomcom, problem
  • applications (25) crisp, geopriv, impp, ldapbis,
    lemonade, opes, provreg, simple, tn3270e, usefor,
    vpim, webdav, xmpp
  • internet (18) IPv4, IPv6, DNS, DHCP dhc,
    dnsext, ipoib, itrace, mip4, nemo, pana, zeroconf
  • oam (22) SNMP, RADIUS, DIAMETER aaa, v6ops,
    netconf,
  • routing (13) forces, ospf, ssm, udlr,
  • security (18) idwg, ipsec, openpgp, sasl, smime,
    syslog, tls, xmldsig,
  • subip (5) layer 2.5 ccamp, ipo, mpls, tewg
  • transport (26) avt (RTP), dccp, enum, ieprep,
    iptel, megaco, mmusic (RTSP), nsis, rohc, sip,
    sipping (SIP), spirits, tsvwg

18
RFCs
  • Originally, Request for Comment
  • now, mostly standards documents that are well
    settled
  • published RFCs never change
  • always ASCII (plain text), sometimes PostScript
  • anybody can submit RFC, but may be delayed by
    review (end run avoidance)
  • see April 1 RFCs (RFC 1149, 3251, 3252)
  • accessible at http//www.ietf.org/rfc/ and
    http//www.rfc-editor.org/

19
IETF process issues
  • Can take several years to publish a standard
  • see draft-ietf-problem-issue-statement
  • Relies on authors and editors to keep moving
  • often, busy people with day jobs ? spurts three
    times a year
  • Lots of opportunities for small groups to delay
    things
  • Original idea of RFC standards-track progression
  • Proposed Standard (PS) kind of works
  • Draft Standard (DS) solid, interoperability
    tested (2 interoperable implementations for each
    feature), but not necessarily widely used
  • Standard (S) well tested, widely deployed

20
IETF process issues
  • Reality very few protocols progress beyond PS
  • and some widely-used protocols are only I-Ds
  • In addition Informational, Best Current Practice
    (BCP), Experimental, Historic
  • Early IETF simple protocols, stand-alone
  • TCP, HTTP, DNS, BGP,
  • Now systems of protocols, with security,
    management, configuration and scaling
  • lots of dependencies ? wait for others to do
    their job

21
Other Internet standards organizations
  • ISOC (Internet Society)
  • legal umbrella for IETF, development work
  • IANA (Internet Assigned Numbers Authority)
  • assigns protocol constants
  • NANOG (North American Network Operators Group)
    (http//www.nanog.org)
  • operational issues
  • holds nice workshop with measurement and real
    world papers
  • RIPE, ARIN, APNIC
  • regional IP address registries ? dole out chunks
    of address space to ISPs
  • routing table management

22
ICANN
  • Internet Corporation for Assigned Names and
    Numbers
  • manages IP address space (at top level)
  • DNS top-level domains (TLD)
  • ccTLD country codes (.us, .uk, )
  • gTLDs (.com, .edu, .gov, .int, .mil, .net, and
    .org)
  • uTLD (unsponsored) .biz, .info, .name, and .pro
  • sTLD (sponsored) .aero, .coop, and .museum
  • actual domains handled by registrars

23
Tema 1 Tecnologías de red.
  • Estructura de Internet
  • Redes core
  • SONET
  • DWDM
  • Redes de acceso
  • Redes cableadas Ethernet et al.
  • Redes inalámbricas IEEE 802.11, UMTS et al.

24
IP and Traditional Transport
  • In the 80s, software based routers were
    interconnected via relatively slow links
  • 56K (early 80s),
  • to fractional T1, to full T1,
  • to T3
  • This was layered over core TDM infrastructure
  • Which was intended for voice and circuits
  • Generally, data folks ignored TDM folks, and vice
    versa

25
Time Division Multiplexing
TimeSlot1
TimeSlot2
TimeSlot4
TimeSlot3
TimeSlot6
TimeSlot1
TimeSlot5
TimeSlot2
SyncBit
SyncBit
MUX
Multiplexed Bit Stream
Sum of sources Total MUXd bit stream
26
SONET SDH
  • SONET - Synchronous Optical NETwork
  • ANSI/Bellcore standard
  • SDH - Synchronous Digital Hierarchy
  • ITU (European) standard
  • Both standards are practically identical
  • Standards for a synchronous digital transmission
    system of TDM traffic over fiber networks.
  • Standards based system for data rates above a T3.

27
SONET/SDH Hierarchy
  • STS - Synchronous Transport Signals
  • 51.84Mbps - base level of SONET hierarchy
  • STM - Synchronous Transport Module
  • 155.52Mbps - base level of SDH hierarchy
  • Exactly equal to STS-3

28
STS/OC/STM
  • STS-n and OC-n are identical -
  • OC-n names are used for optical interconnects
  • STS-n names are used for electrical interconnects
  • OC-n is exactly n times the rate of an OC-1
    signal.
  • STM-1 signal is exactly 3 times the rate of an
    STS-1 signal
  • STM-n is exactly n times the rate of an STM-1
    signal

29
ADM, Terminal, Repeater
  • SONET/SDH terminal - a mux/demux that creates a
    SONET signal and terminates paths.
  • SONET/SDH ADM (Add/Drop Multiplexer) - a
    mux/demux that can separate individual STS-n
    signals from a higher level signal.
  • SONET/SDH repeater- a physical level regenerator
    that also terminates section level overhead to
    allow section level management.

30
SONET/SDH - Path/Section/Line
  • In Sonet/SDH systems a strong designation of
    levels of overhead are kept.
  • Section is lowest level
  • Repeater to repeater
  • Line is middle layer
  • Path is top/longest layer
  • from entrance to SONET system to exit of SONET
    system

31
SONET/SDH - Section Line Overhead
  • The section overhead is the first 3 rows of the
    first 3 columns (9 bytes) per frame.
  • The line overhead is the lower 6 rows of the
    first 3 columns (18 bytes) per frame.
  • An STS-1 frame consists of 810 bytes (octets)
    sent in 125µs.
  • 810 8 8000 51.84Mbps
  • The 810 bytes are arranged as 90 columns x 9 rows
  • 3 columns are overhead
  • 87 columns are actual data

87 columns
A1
A2
C1
Section Overhead
B1
E1
F1
D1
D2
D3
STS-1 Payload
H1
H2
H3
B2
K1
K2
D4
D5
D6
Line Overhead
D7
D8
D9
D10
D11
D12
Z1
Z2
Z3
32
STS concatenated signals
  • Multiple STS-1s can be grouped together into a
    single higher bit rate facility.
  • Extra overhead bytes are ignored.
  • Technically, any number of STS-1s can be grouped,
    but the only groupings normally supported are
  • STS-3C, STS-12C, STS-48C
  • Generally a grouping must fall on a boundary of
    the same size inside of the OC-n carrier
  • A STS-3C must fall on a boundary of 3
  • STS-12C must fall on a boundary of 12
  • Typically used for situations where ATM or
    Packets are sent over a SONET network.

33
Traditional View of Routers and Links
34
Reality has always been more complex
Terminal Multiplexer
Terminal Multiplexer
SONET/SDH ADM
SONET/SDH ADM
SONET/SDH DCS
SONET/SDH ADM
SONET/SDH ADM
SONET/SDH DCS
SONET/SDH DCS
Terminal Multiplexer
Terminal Multiplexer
SONET/SDH ADM
SONET/SDH ADM
Terminal Multiplexer
Terminal Multiplexer
35
Optical Fiber Evolution
  • Fiber is better than copper wire
  • Purity low attenuation and distortion
  • Longer distances, lower bit error rates
  • Higher frequency signals massive bandwidth
  • Different wavelengths massive bandwidth
  • Immunity to noise
  • Security difficult to tap
  • Small size and weight
  • Easier installation
  • Bundles of fibers in same space as copper wire
  • Multimode fiber
  • Low cost LEDs, not lasers
  • Many wavelengths (modes)
  • Dispersion limits bandwidth and distance
  • Light pulses spread out
  • Intramodal different delay per mode
  • Typically 2 km maximum distance
  • Large diameter cores for multiple modes
  • Initially flat profile
  • Stepped end improves performance
  • Single-mode fiber
  • One wavelength small core
  • Less interference and loss
  • Greater distance (up to 100 km)
  • More expensive components lasers
  • Minimized dispersion point at 1310 nm
  • Not suitable for EDFA (Erbium Doped Fiber-optic
    Amplifier)
  • Non-zero dispersion shifted fiber
  • Optimized for longer distances
  • Optimized for higher bandwidth
  • Minimized dispersion point shifted to 1550 nm
  • Suitable for Erbium-based optical amplifiers
  • Silica-based fibers have lowest attenuation at
    1550 nm, not 1310

36
Wave Division Multiplexing
SONET/SDH ADM
Single Fiber
SONET/SDH ADM
SONET/SDH ADM
From One Wavelength Per Fiber to Many
ADM
ADM
WDM Node
WDM Node
ADM
ADM
OT
OT
ADM
ADM
Single Fiber
ADM
ADM
OT Optical Transponder
37
WDM System Elements
SONET/SDH ADM
SONET/SDH ADM
SONET/SDH ADM
SONET/SDH ADM
SONET/SDH ADM
SONET/SDH ADM
Regenerators
38
TDM and WDM Relationship
Laser Output
l1
l1 ln
OT
ln
WDM changes TDM bit stream into wavelengths
between 1532 nm and 1560 nm
TDM generates output from sum of inputs into a
single bit stream
39
Dense and Ultra Dense WDM
WDM 8 Lambdas
l1
l1
l2
l2
2.5 Gbps per lambda
l8
l8
EDFA Erbium Doped Fiber-optic Amplifier
EDFA Erbium Doped Fiber-optic Amplifier
40
Dense and Ultra Dense WDM
l1
l1
l2
l2
DWDM 40 Lambdas
10 Gbps per lambda
l39
l39
l40
l40
EDFA Erbium Doped Fiber-optic Amplifier
41
Dense and Ultra Dense WDM
l1
l1
l2
l2
UDWDM 192 Lambdas
l3
l3
40 Gbps per lambda
l190
l190
l191
l191
EDFA Erbium Doped Fiber-optic Amplifier
l192
l192
42
Tema 1 Tecnologías de red.
  • Estructura de Internet
  • Redes core
  • SONET
  • DWDM
  • Redes de acceso
  • Redes cableadas Ethernet et al.
  • Redes inalámbricas IEEE 802.11, UMTS et al.

43
Los estándares 802.3 de IEEE
44
IEEE 802 standard
45
Estándares de ethernet sobre optico
  • ITU-T G.7041 Generic Framing Procedure (GFP)
  • ITU-T X.86 Link Access Protocol (LAPS)
  • ITU-T H.707 Virtual Concatenation (VCAT)
  • ITU-T G.7042 Link Capacity Adjustment Scheme
    (LCAS)
  • Otros
  • IEEE 802.1X Port Based Network Access Control
  • IEEE 802.1D Ethernet switching
  • IEEE 802.1Q Virtual LAN (VLAN)
  • IEEE 802.1P Priorización de tráfico a nivel 2
  • IETF MPLS Multi-Protocol Label Switching
  • IEEE 802.17 Resilient Packet Ring (RPR)
  • Ver
  • http//grouper.ieee.org/groups/802/3/
  • http//grouper.ieee.org/groups/802/1/

46
Trama ethernet
  • Los datos trasmitidos se encapsulan en un
    contenedor, que se llama trama
  • Este formato de trama DEFINE Ethernet
  • Históricamente, existen dos tipos de tramas
  • 802.3 Framing usa en campo de longitud de trama
    (Length) despues del campo de Source Address
  • Ethernet II (DIX) Framing usa(ba) el campo de
    tipo de trama (type) despues del campo Source
    Address
  • Ambos tipos de tramas están definidos y
    soportados dentro de IEEE 802.3

47
Trama ethernet
  • El tamaño de trama varía desde 64 a 1518 Bytes,
    excepto cuando se usa el identificador (tag) de
    VLAN

48
802.1Q/P
  • User Priority- Defines user priority, giving
    eight (23) priority levels. IEEE 802.1P defines
    the operation for these 3 user priority bits.
  • CFI- Canonical Format Indicator is always set to
    zero for Ethernet switches. CFI is used for
    compatibility reason between Ethernet type
    network and Token Ring type network. If a frame
    received at an Ethernet port has a CFI set to 1,
    then that frame should not be forwarded as it is
    to an untagged port.
  • VID- VLAN ID is the identification of the VLAN,
    which is basically used by the standard 802.1Q.
    It has 12 bits and allow the identification of
    4096 (212) VLANs. Of the 4096 possible VIDs, a
    VID of 0 is used to identify priority frames and
    value 4095 (FFF) is reserved, so the maximum
    possible VLAN configurations are 4,094.
  • Length/Type- 2 bytes. This field indicates either
    the number of MAC-client data bytes that are
    contained in the data field of the frame, or the
    frame type ID if the frame is assembled using an
    optional format.
  • Data- Is a sequence of nbytes (48lt n lt1500) of
    any value. The total frame minimum is 64bytes.
  • Frame check sequence (FCS)- 4 bytes. This
    sequence contains a 32-bit cyclic redundancy
    check (CRC) value, which is created by the
    sending MAC and is recalculated by the receiving
    MAC to check for damaged frames.

49
Servicios Metropolitanos
  • Algunos servicios son
  • Conectividad Internet
  • Transparent LAN service (punto a punto LAN to
    LAN)
  • L2VPN (punto a punto o multipunto a multipunto
    LAN to LAN)
  • Extranet
  • LAN a Frame Relay/ATM VPN
  • Conectividad a centro de backup
  • Storage area networks (SANs)
  • Metro transport (backhaul)
  • VoIP
  • Algunos se están ofreciendo desde hace años. La
    diferencia está en que ahora se ofrecen usando
    conectividad Ethernet !!

50
Evolución de Ethernet
Acceso
Distribución Metro
Metro Core
Casa
Residencial
MDU
ATM SONET/SDH
ATM SONET/SDH
ATM ADSL T1/E1 FR ATM
Global Internet
STU
Empresa
MTU
Optical Ethernet EoMPLS VPLS EoRPR NG-SONET(EoS) M
etro DWDM
Optical Ethernet EoMPLS VPLS RPR NG-SONET(EoS) Met
ro DWDM
IP ADSL IP VDSL EPON EFM Optical
Ethernet EoRPR NG-SONET(EoS)
Global Internet
51
Servicio Ethernet Modelo de referencia
  • Customer Equipment (CE) se conecta a través de
    UNI
  • CE puede ser un
  • router
  • Bridge IEEE 802.1Q (switch)
  • UNI (User Network Interface)
  • Standard IEEE 802.3 Ethernet PHY and MAC
  • 10Mbps, 100Mbps, 1Gbps or 10Gbps
  • Soporte de varias clases de servicio (QoS)
  • Metro Ethernet Network (MEN)
  • Puede usar distintas tecnologías de transporte y
    de provisión de servicio
  • SONET/SDH, WDM, PON, RPR, MAC-in-MAC, QiQ (VLAN
    stack), MPLS

CE
UNI
Metro Ethernet Network (MEN)
CE
UNI
CE
52
Servicio Ethernet Modelo (2)
  • Sobre el anterior modelo, se añade un cuarto
    ingrediente una Ethernet Virtual Connection
    (EVC)
  • EVC es una asociación entre dos o más UNI
  • Es creada por el proveedor del servicio para un
    cliente
  • Una trama enviada en un EVC puede ser enviada a
    uno o más UNIs del EVC
  • Nunca será enviada de vuelta al UNI de entrada.
  • Nunca será enviada a un UNI que no pertenezca al
    EVC.
  • Las EVCs pueden ser
  • Punto a punto (E-Line)
  • Multipunto a multipunto (E-LAN)
  • Cada tipo de servicio ethernet tiene un conjunto
    de atributos de servicio y sus correspondientes
    parámetros que definen las capacidades del
    servicio.

53
Atributos de un servicio en particular Ethernet
  • Multiplexación de servicios
  • Asocia una UNI con varias EVC. Puede ser
  • Hay varios clientes en una sóla puerta (ej. En un
    POP UNI)
  • Hay varias conexiones de servicios distintos para
    un solo cliente
  • Transparencia de VLAN
  • Significa que proveedor del servico no cambia el
    identificador de la VLAN ( el MEN aparece como un
    gran switch)
  • En el servicio de acceso a Internet tiene poco
    importancia
  • Bundling
  • Más de una VLAN de cliente está asociada al EVC
    en una UNI
  • Etc.

54
Atributos
  • Atributos de UNI
  • identificador, tipo de medio, velocidad, duplex,
    etc
  • Atributo de soporte de VLAN tag
  • Atributo de multiplexación de servicio
  • Bundling attribute
  • Security filters attribute
  • etc
  • Atributos de EVC
  • Parámetros de tráfico (CIR, PIR, in, out, etc)
  • Parámetros de prestaciones (delay, jitter, etc)
  • Parámetros de Clase de Servicio (VLAN-ID, valor
    de .1p, etc)
  • Atributo de Service frame delivery
  • Unicast frame delivery
  • Multicast frame delivery
  • etc

55
Servicio Ethernet Line (E-Line)
Point-to-Point Ethernet Virtual Circuits (EVC)
Servers
IP Voice
UNI
IP PBX
Metro Ethernet Network
CE
Data
CE
1 or more UNIs
Video
IP Voice
UNI
CE
Data
56
Servicio Ethernet Line (E-Line)
  • Una E-Line puede operar con ancho de banda
    dedicado ó con un ancho de banda compartido.
  • EPL Ethernet Private Line
  • Es un servicio EVC punto a punto con un ancho de
    banda dedicado
  • El cliente siempre dispone del CIR
  • Normalmente en canales SDH (en NGN) ó en redes
    MPLS
  • Es como una línea en TDM, pero con una interfaz
    ethernet
  • EVPLEthernet Virtual Private Line
  • En este caso hay un CIR y un EIR y una métrica
    para el soporte de SLAs
  • Es similar al FR
  • Se suele implementar con canales TDM compartidos
    ó con redes de conmutación de paquetes usando
    SWs y/o routers

57
Servicio Ethernet LAN (E-LAN)
58
Servicio Ethernet LAN (E-LAN)
  • Una E-LAN puede operar con ancho de banda
    dedicado ó con un ancho de banda compartido.
  • EPLan Ethernet Private LAN
  • Suministra una conectividad multipunto entre dos
    o más UNIs, con un ancho de banda dedicado.
  • EVPLan Ethernet Virtual Private LAN
  • Otros nombres
  • VPLS Virtual Private Lan Service
  • TLS Transparent Lan Service
  • VPSN Virtual Private Switched Network
  • La separación de clientes vía encapsulación las
    etiquetas de VLANs del proveedor no son
    suficientes (4096)
  • Es el servicio más rentable desde el punto de
    vista del proveedor.

59
Metro tecnologías...
  • Los servicios Metro Ethernet services no
    necesitan que toda la red de nivel 2 sea
    ethernet tambien puede ser
  • Ethernet over SONET/SDH (EOS)
  • Resilient Packet Ring (RPR)
  • Ethernet Transport
  • Ethernet sobre MPLS

60
Implementaciones de los EVC (Ethernet Virtual
Conn.)
  • Virtual Private LAN Services (VPLS)
  • Es un tipo de VPN de nivel 2
  • La red del proveedor emula la función de un
    conmutador de LAN ó bridge, para conectar todos
    los UNI del cliente, para formar una única VLAN
  • Los requerimientos en el CE son distintos a los
    de antes
  • Cada PE debe actuar como un bridge de ethernet
  • Se puede implementar poniendo ethernet en MPLS ó
    bien, haciendo stack de VLAN usando Q-in-Q
  • Ver http//vpls.org

61
Tema 1 Tecnologías de red.
  • Estructura de Internet
  • Redes core
  • SONET
  • DWDM
  • Redes de acceso
  • Redes cableadas Ethernet et al.
  • Redes inalámbricas IEEE 802.11, UMTS et al.

62
Taxonomy
Wireless Networking
Multi-hop
Single Hop
Infrastructure-less (ad-hoc)
Infrastructure-based (Hybrid)
Infrastructure-less (MANET)
Infrastructure-based (hubspoke)
802.11
802.16
Bluetooth
802.11
Cellular Networks
Car-to-car Networks (VANETs)
Wireless Sensor Networks
Wireless Mesh Networks
63
WLANs, El estándar IEEE 802.11
  • En el 1997 nace el
  • IEEE Working Group for WLAN Standards
  • http//grouper.ieee.org/groups/802/11/index.html
  • Se define el MAC y tres diferentes niveles
    físicos, que operan a 1Mbps y 2Mbps
  • Infrarrojos (IR) en banda base
  • Frequency hopping spread spectrum (FHSS), banda
    de 2,4 GHz
  • Direct sequence spread spectrum (DSSS), banda de
    2,4 GHz
  • IEEE Std 802.11a (diciembre 1999)
  • Otro estándar de nivel físico Orthogonal
    frequency domain multiplexing (OFDM)
  • Hasta 54 Mbps
  • IEEE Std 802.11b (enero 2000)
  • Extensión de DSSS hasta 11 Mbps
  • IEEE Std 802.11g (Junio 2003)
  • Etc.

http//standards.ieee.org/getieee802/802.11.html
64
Arquitectura 802.11
65
El MAC entrega de datos fiable
  • CSMA/CA con binary exponential backoff
  • El protocolo mínimo consiste de dos tramas
    DATOSACK
  • El standard propone RTS-CTS-DATOS-ACK
  • Los 5 valores de timing
  • Slot time
  • SIFS short interframe space
  • PIFS PCF interframe space (SIFS1slot)
  • DIFS DCF interframe space (SIFS2slots)
  • EIFS extended interframe space

66
Mecanismo de detección de portadora
  • Se basa en el network allocation vector (NAV)

DIFS
data
RTS
fuente
ACK
CTS
destino
DIFS
NAV (RTS)
ventana de contienda
otro STA
NAV (CTS)
defer access
67
QoS 802.11e and WMM
  • QoS needed for audio, voice, video
  • Original Wi-Fi didnt have QoS
  • IEEE 802.11e is new QoS standard
  • Still in process after more than 4 years
  • Both prioritized and guaranteed QoS
  • WMM (Wi-Fi Multimedia)
  • Prioritized QoS subset of 802.11e draft
  • Widely accepted by 802.11e members
  • Added to Wi-Fi certification in September 2004
  • Already included in some products

68
WMM for Video
Source Wi-Fi Alliance
69
Bluetooth Specifications
  • Bluetooth is a system solution comprising
    hardware, software and interoperability
    requirements. The Bluetooth specifications
    specify the complete system.
  • De facto standard - open specifications.
  • Two part document - Volume 1Core and Volume
    2Profiles.
  • Bluetooth specs developed by Bluetooth SIG.
  • February 1998 The Bluetooth SIG is formed
  • promoter company group Ericsson, IBM, Intel,
    Nokia, Toshiba
  • May 1998 The Bluetooth SIG goes public
  • July 1999 1.0A spec (gt1,500 pages) is published
  • December 1999 ver. 1.0B is released
  • December 1999 The promoter group increases to 9
  • 3Com, Lucent, Microsoft, Motorola
  • February 2000 There are 1,500 adopters
  • 0.7 ---gt 0.9 ---gt 1.0A ---gt 1.0B ---gt 1.1 --gt
  • November 2003 release 1.2
  • Currently (November 2004), release 2.0
  • (aka EDR or Extended Data Rate) triples the data
    rate up to about 2 Mb/s

70
release 2.0 the new partitioning
71
Bluetooth usage
  • Low-cost, low-power, short range radio ? a cable
    replacement technology
  • Common (File transfer, synchronisation, internet
    bridge, conference table)
  • Hidden computing (background synchronisation,
    audio/video player)
  • Future (PC login, remote control)
  • Why not use Wireless LANs?
  • power
  • cost

72
Bluetooth RF
  • 1 Mb/s symbol rate
  • Normal range 10m (0dBm)
  • Optional range 100m (20dBm)
  • Normal transmission power 0dBm (1mW)
  • Optional transmission power -30 to 20dBm (100mW)
  • Receiver sensitivity -70dBm
  • Frequency band 2.4Ghz ISM band
  • Gross data rate 1Mbit/s
  • Max data transfer 72156kbps/3 voice channels
  • Power consumption 30uA(max), 300uA(standby),
    50uA(hold/park)
  • Packet switching protocol based on frequency hop
    scheme with 1600 hops/s

73
Bluetooth Power Class Table
74
Bluetooth Network Topology
  • Bluetooth devices have the ability to work as a
    slave or a master in an ad hoc network. The types
    of network configurations for Bluetooth devices
    can be three.
  • Single point-to-point (Piconet) In this topology
    the network consists of one master and one slave
    device.
  • Multipoint (Piconet) Such a topology combines
    one master device and up to seven slave devices
    in an ad hoc network.
  • Scatternet A Scatternet is a group of Piconets
    linked via a slave device in one Piconet which
    plays master role in other Piconet.

The Bluetooth standard does not describe any
routing protocol for scatternets and most of the
hardware available today has no capability of
forming scatternets. Some even lack the ability
to communicate between slaves of one piconet or
to be a member of two piconets at the same time.
75
Bluetooth stack short version
Applications
SDP
RFCOMM
L2CAP
HCI
Link Manager
Baseband
RF
76
Transport Protocol Group (contd.)
  • Radio Frequency (RF)
  • Sending and receiving modulated bit streams
  • Baseband
  • Defines the timing, framing
  • Flow control on the link.
  • Link Manager
  • Managing the connection states.
  • Enforcing Fairness among slaves.
  • Power Management
  • Logical Link Control Adaptation Protocol
  • Handles multiplexing of higher level protocols
  • Segmentation reassembly of large packets
  • Device discovery QoS
  • The Radio, Baseband and Link Manager are on
    firmware.
  • The higher layers could be in software.
  • The interface is then through the Host Controller
    (firmware and driver).
  • The HCI interfaces defined for Bluetooth are
    UART, RS232 and USB.

Source Farinaz Edalat, Ganesh Gopal, Saswat
Misra, Deepti Rao
77
Physical Link Definition
  • Synchronous Connection-Oriented (SCO) Link
  • circuit switching
  • symmetric, synchronous services
  • slot reservation at fixed intervals
  • Asynchronous Connection-Less (ACL) Link
  • packet switching
  • (a)symmetric,
  • asynchronous services
  • polling access scheme


78
ACL data rates
79
Multi-slot packets
Single slot
Three slot
Five slot
80
Symmetric single slot
fn fn1 fn2 fn3 fn4
fn5 fn6 fn7 fn8 fn9
fn10 fn11 fn12
Master
Slave
81
Mixed Link Example
MASTER
SLAVE 1
SLAVE 2
SLAVE 3
82
Bluetooth Connection States
  • There are four Connection states on Bluetooth
    Radio
  • Active Both master and slave participate
    actively on the channel by transmitting or
    receiving the packets (A,B,E,F,H)
  • Sniff In this mode slave rather than listening
    on every slot for master's message for that
    slave, sniffs on specified time slots for its
    messages. Hence the slave can go to sleep in the
    free slots thus saving power (C)
  • Hold In this mode, a device can temporarily not
    support ACL packets and go to low power sleep
    mode to make the channel available for things
    like paging, scanning etc (G)
  • Park Slave stays synchronized but not
    participating in the Piconet, then the device is
    given a Parking Member Address (PMA) and it loses
    its Active Member Address (AMA) (D,I)

Bluetooth Connection States
83
Bluetooth Forming a Piconet
  • Inquiry Inquiry is used to find the identity of
    the Bluetooth devices in the close range.
  • Inquiry Scan In this state, devices are
    listening for inquiries from other devices.
  • Inquiry Response The slave responds with a
    packet that contains the slave's device access
    code, native clock and some other slave
    information.
  • Page Master sends page messages by transmitting
    slave's device access code (DAC) in different hop
    channels.
  • Page Scan The slave listens at a single hop
    frequency (derived from its page hopping
    sequence) in this scan window.
  • Slave Response Slave responds to master's page
    message
  • Master Response Master reaches this substate
    after it receives slave's response to its page
    message for it.

Forming a Piconet Procedures
84
Tema 1 Tecnologías de red.
  • Estructura de Internet
  • Redes core
  • SONET
  • DWDM
  • Redes de acceso
  • Redes cableadas Ethernet et al.
  • Redes inalámbricas IEEE 802.11, UMTS et al.

85
2G Technology Summary
  • TDMA Time Division Multiple Access
  • Standardized in 1990 as IS-54
  • Provides 3-6 times capacity increase over AMPS
    (1G)
  • Peak data rate of 14.4kpbs (can bundle up to 8
    channels)
  • Introduced authentication and encryption for
    security
  • GSM Global System of Mobile communications
  • Standardized in 1992, based on TMDA technology
  • Improved battery life over TDMA
  • GPRS peak data rates of 140 kbps EDGE data rates
    of 180kbps
  • CDMA Code Division Multiple Access
  • Standardized in 1993 as IS-95
  • Provides 1.5-2 times capacity increase over TDMA
  • Peak data rate of 14.4kpbs (can bundle up to 8
    channels)

86
2G Winners Losers
  • TDMA
  • Marginally better capacity than GSM, marginally
    worse battery life
  • No evolution path beyond 2G DEAD END !!
  • CDMA
  • Lots of hype on capacity, delivered on upwards of
    2x capacity improvement over TDMA/GSM
  • Clear evolution to 3G
  • GSM
  • International Roaming and Compatibility
  • Clear evolution to 3G
  • Defacto Global Standard

87
Evolution to 3GDrivers Capacity, Data Speed,
Cost
Expected market share
90
TDMA
EDGE
EDGE Evolution
3GPP Core Network
GSM
GPRS
WCDMA
HSDPA/HSUPA
PDC
cdmaOne
10
CDMA2000 1x
CDMA2000 1x EV/DO
CDMA2000 EV/DO Rev A
2G
First Step into 3G
3G phase 1
Evolved 3G
88
Mobile Networks Evolution
4G
HSDPA
UMTS
3G
2G
EDGE
GPRS
2015
1995
2005
89
3G new network
Packet switched Core network
GSM/GPRS Radio network
2G SGSN
GGSN
PCU
External IP
network
BSC
GSM
GPRS
HLR
UMTS/ HSDPA
2G MSC
GMSC
External
voice
network
Circuit switched Core network
90
3G Network The Future
  • New network
  • No voice overload
  • Increased capacity by Spectrum efficiency
  • Better performances
  • Higher throughput ? Faster download (Max 384kbps)
  • Lower latency ? Faster browsing
  • Better Services
  • Seamless hand-over to GPRS (service continuity)
  • New way to design applications
  • Video
  • Future proof technology HSDPA

91
3G/HSDPA for business innovation
text ? picture ? video
High speed internet access High speed LAN access
Video Telephony Mobile TV Full track
music Enhanced email
Push email Photo Picture Messaging Customized in
fotainment
Text messaging Voice
3G / HSDPA
2G/EDGE
SPEED
92
and Beyond
  • Technology Convergence on OFDM (Orthogonal
    Frequency Division Multiple Access)
  • WIMAX
  • Standardized by IEEE 802.16, evolution of 802.11
    (Wi-Fi)
  • Improved bandwidth, encryption and coverage over
    WiFi
  • Theoretical peak data rates of 70Mbps (practical
    peak 2Mbps)
  • Improved QoS better enables applications such as
    VoIP or IPTV
  • Ideal application is for last mile connectivity
    to the home or business
  • Intel plans to embed WiMAX chips as part of
    Intel Inside
  • L3GTE/HSOPA
  • Early standardization work starts in 3GPP R8
  • Improved bandwidth, latency over UMTS/HSxPA
  • Radio technology based on MIMO-OFDM, peak data
    rates of up to 70Mbps
  • Network simplification

93
Market Segments
Voice
Broadband
Mobile
WiMAX 16e HSDPA to OFDM EV-DO to OFDM
Cellular
2.5G
Local
802.11a/b/g 802.11n MIMO Mesh
WiFi
Cordless
Fixed
WiMAX 16d DSL / Cable
POTS
Dialup
94
Network Convergence - IMS
Unlicensed Mobile Access (UMA) and the IP
Multimedia Subsystem (IMS) -- two standard
architectures under the 3GPP umbrella -- both
support fixed-mobile convergence (FMC). But their
approaches to FMC have little in common. UMA is a
highly constrained approach to a single service
-- dual-mode access to GSM networks -- while IMS
is an open platform for all types of services and
all types of networks. UMA offers mobile network
operators (MNOs) a quick fix, but IMS promises
profitable new services and sustainable growth
for all service providers.
Applications
Media Resources
Access Network
Audio/ Video
Multimedia Services
Messaging Services
Web / WAP Services
Streaming Services
WLAN
Service Control
GPRS UMTS
TDM Packet Interworking
Presence / GLMS
R4 CDMAPSTN
WiMAX
ASN
HSOPA OFDM/MIMO
ASG
IP/MPLS Core
Peer IPNetwork
BRAS
95
Market Trends
  • Media Convergence Multiple Play
  • Dual Play High-Speed Internet Fixed Line
  • Triple Play Dual Play TV
  • Quadruple Play Triple Play Wireless
  • Challenge Consolidated Invoice and Price Points
  • Fixed Mobile Convergence
  • Dual Mode connectivity
  • Cellular / Cordless (DECT, ADSL/Bluetooth)
  • WLAN / WWAN
  • Challenge Technology standardization
  • MVNO Mobile Virtual Network Operator
  • Wireless Service Reseller, wholesales access from
    wireless operators
  • Discount Lifestyle MVNOs
  • Segment, Product, Utilization Driven
  • Challenge Market Saturation Service
    Differentiation

96
Market Trends (continued)
  • Multimedia use of several media types to convey
    information
  • Effective information delivery across many
    disciplines art, education, telecommunications,
    medicine
  • IMS enables multimedia services for mobile users
  • VoIP
  • Challenge User Interface, Form Factor, lack of
    killer app
  • Presence Always on, always connected
  • Combine Mobility Reachability
  • Effectively bring Popularity of IM to mobile
    phones (AOL, Yahoo!, MSN, Skype)
  • Opportunity for standardization interworking
    based on SIP/SIMPLE
  • Challenge Standardization always on
    connectivity
About PowerShow.com