T2_tecnologias LANx - GRC - UPV

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27 Οκτ 2013 (πριν από 3 χρόνια και 7 μήνες)

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TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010


http://www.grc.upv.es/docencia/tra/

Tema
2:

Tecnologías
LAN.



Evolución de Ethernet.



Ethernet para
MANs


VPLS



EtherChannel



Resilient

Ethernet: HSRP

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Overview


Ethernet is the dominant LAN technology.


Easy to implement; flexible.


10BASE5, 10BASE2, & 10BASE
-
T Ethernet


Manchester encoding


Ethernet timing limits


10BASE
-
T wiring parameters


100
-
Mbps Ethernet (Fast Ethernet)


Gigabit Ethernet


MAC, frame formats, & transmission process


media and encoding


pinouts and wiring


Gigabit and 10
-
Gigabit Ethernet

2

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

10 Mbps Ethernet


4 common features of Legacy Ethernet:


timing parameters, frame format, transmission processes, &
basic design rule.


Asynchronous


Uses Preamble and SFD for synchronization


Slot Time


For speeds ≤1000 Mbps, minimum transmission time


3

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

10BaseT


Introduced in 1990


UTP cheaper & easier to install than co
-
ax.


Star or extended star topology.


Supports half
-

& full
-
duplex.


10 Mbps at half
-
duplex; 20 Mbps at full
-
duplex.


Manchester encoding


Max unrepeated distance 100m


UTP Categories:


3
-

16 Mhz, 100 ohms


4


20 Mhz, 100 ohms


5


100 Mhz , 100 ohms


5e


350 Mhz, 100 ohms

4

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

10BaseT Wiring & Architecture


Star topology


Hub or switch as concentration point.


Switch divides into separate collision domains.


Design concern


minimize delay between distant stations.


5

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

100 Mbps or Fast Ethernet


Two technologies:


100Base
-
TX : copper UTP


100Base
-
FX : multimode optical fiber


Same frame format as 10 Mbps Ethernet


10x faster than 10Base
-
T


Timing is more critical;


more susceptible to noise.


Uses two encoding steps


4B/5B


Actual line encoding.

6

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

1000 Mbps or Gigabit Ethernet


Standards


IEEE 802.3ab


Gigabit using Cat 5, or higher.


IEEE 802.3z
-

Gigabit over optical fiber.


1000Base
-
TX, 1000Base
-
SX, & 1000Base
-
LX use same
timing, transmission, & frame format.


Uses two separate encoding steps:


At physical layer, bit patterns from the MAC layer are converted
into symbols.


frame is coded into control & data symbols to increase in
network throughput.




7

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

1000Base
-
T


Designed for Cat 5e or better
UTP.


uses all four pairs of wires;
full
-
duplex transmissions on
each wire pair!
-

250 Mbps per
pair; 1000 Mbps for 4 wire
pairs.


Data is divided into 4 parallel
streams, encoded, transmitted,

detected, and reassembled.


Supports both half and full
duplex.


Full
-
duplex is widespread.


4D
-
PAM5


Pulse Amplitude
Modulation

8

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

1000Base
-
SX and LX


IEEE 802.3 standard recommended preferred backbone
technology


Timing, frame format, & transmission are common to all
versions of 1000 Mbps.


Uses 8B/10B encoding; and NRZ line encoding.

9

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

1000Base
-
SX and LX (2)


SX vs LX


SX is short
-
wavelength


850 nm; multimode.


LX is long
-
wavelength


1310 nm; single or
multimode.


MAC method treats link
as point
-
to
-
point.


Separate fibers for Tx and
Rx.


Inherently full duplex.


Gigabit Ethernet permits
only a single repeater
between two stations.

1
0

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Gigabit Ethernet Architecture


Distance limitations of full
-
duplex links


limited only by the medium; not round
-
trip delay.


Auto
-
Negotiation recommended for all links between
station & hub or switch.


to permit highest common performance.

1
1

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

10 Gigabit Ethernet


IEEE 802.3ae standard (2002).


10
Gbps

full
-
duplex transmission over fiber.


Use in LANs, MANs, WANs.


distance to 40 km over single
-
mode fiber.


compatibility with SONET and SDH networks.


Properties


Same Frame format


Compatible with legacy, fast, & gigabit, with no reframing or
protocol conversions.


Bit time is 0.1 nanoseconds.


Full
-
duplex only (CSMA/CD not necessary).


IEEE 802.3
sublayers

within OSI Layer 2 are preserved.


Some additions to accommodate 40 km fiber links and
interoperability with SONET/SDH technologies.


Flexible, efficient, reliable, relatively low cost end
-
to
-
end
Ethernet networks become possible.


1
2

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

10 Gigabit Ethernet (3)


Implementations being considered:


10GBASE
-
SR


for short distances (26


82 m) over multimode fiber.


10GBASE
-
LX4


distances 240 m to 300 m over multimode fiber, and 10 km over
single
-
mode fiber.


10GBASE
-
LR & 10GBASE
-
ER


10 km & 40 km over single
-
mode fiber.


10GBASE
-
SW, 10GBASE
-
LW, & 10GBASE
-
EW


to work with OC
-
192 synchronous transport module SONET/SDH
WAN equipment.

1
3

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

10 Gigabit Ethernet Architecture


Issues of synchronization, bandwidth, and Signal
-
to
-
Noise Ratio:


10
-
Gigabit Ethernet uses two encoding steps.


uses codes (symbols) for user data give efficient transmission.


encoded data provides
synchronization,
efficient use of BW,
and improved Signal
-
to
-
Noise
Ratio.



1
4

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Future of Ethernet


Ethernet is evolving into LAN, MAN, & WAN technology.


Standards for 40, 100, or even 160
Gbps

are being developed.


Full
-
duplex high
-
speed Ethernet technologies are taking
over even
QoS
-
intensive applications.


Like: IP telephony & video multicast.

1
5

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Evoluci
ó
n de Ethernet

1
6

Optical Ethernet

EoMPLS

VPLS

EoRPR

NG
-
SONET(EoS)

Metro DWDM

Optical Ethernet

EoMPLS

VPLS

RPR

NG
-
SONET(EoS)

Metro DWDM

IP ADSL

IP VDSL

EPON

EFM

Optical Ethernet

EoRPR

NG
-
SONET(EoS)

Acceso

Distribución Metro

Metro Core

Global

Internet

ATM

SONET/SDH

ATM

SONET/SDH

ATM ADSL

T1/E1

FR

ATM

Global

Internet

Casa

MDU

STU

MTU

Residencial

Empresa

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

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 !!


1
7

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

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


1
8

CE

CE

CE

UNI

Metro
Ethernet
Network
(MEN)

UNI

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

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
EVC
´
s

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.



1
9

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

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.

2
0

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Atributos


Atributos de UNI:


identificador, tipo de medio, velocidad,
duplex
,
etc


Atributo de soporte de VLAN
tag



Atributo de
multiplexación

de servicio


Security
filters

attribute


etc


Atributos de EVC:


Parámetros de tráfico (CIR, EIR, in,
out
,
etc
)


Committed

Information

Rate

(CIR)


Excess

Information

Rate

(EIR)


Parámetros de prestaciones (
delay
,
jitter
,
etc
)


Parámetros de Clase de Servicio (VLAN
-
ID, valor de .1p,
etc
)


Multicast

frame

delivery


etc


2
1

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Servicio Ethernet Line (E
-
Line)

2
2

Data

UNI

CE

CE

CE

Point
-
to
-
Point

Ethernet Virtual Circuits
(EVC)

Metro

Ethernet

Network

1 or more
UNIs

UNI

Video

IP PBX

Servers

Data

IP Voice

IP Voice

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

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 ó en redes MPLS


Es como una línea en TDM, pero con una interfaz
ethernet


EVPL
: Ethernet Virtual
Private

Line


En este caso hay un CIR y un EIR y una métrica para el soporte
de
SLAs

(
service

level

agreement
)


Es similar al
Frame

Relay


Se suele implementar con canales TDM compartidos ó con redes
de conmutación de paquetes usando
SW
´
s

y/o
routers

2
3

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Servicio Ethernet LAN (E
-
LAN)

2
4

CE

CE

CE

Metro

Ethernet

Network

CE

Multipoint
-
to
-
Multipoint

Ethernet Virtual Circuit

(EVC)

UNI

UNI

UNI

UNI

IP PBX

Servers

Data

Data

Data

IP Voice

IP Voice

IP Voice

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

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
UNI
´
s
,
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


2
5

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Un ejemplo: ONO


2
6

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Un ejemplo: ONO

2
7

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Otro ejemplo:
Telefonica

2
8

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Otro ejemplo:
Telefonica

2
9

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Virtual Private LAN Service (VPLS)


VPLS
defines an architecture

allows MPLS networks offer
Layer 2 multipoint Ethernet Services


SP emulates an IEEE Ethernet bridge network (virtual)


Virtual Bridges linked with
MPLS Pseudo Wires


Data Plane used is same as EoMPLS (point
-
to
-
point)

PE

PE

CE

CE

VPLS is an Architecture

CE

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Virtual Private LAN Service


End
-
to
-
end architecture

that allows MPLS networks to
provide
Multipoint Ethernet services


It is “
Virtual
” because multiple instances of this service
share the same physical infrastructure


It is “
Private
” because each instance of the service is
independent and isolated from one another


It is “
LAN Service
” because it emulates Layer 2
multipoint connectivity between subscribers


TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Why Provide A Layer 2 Service?


Customer have
full operational control

over their
routing neighbours


Privacy of addressing space

-

they do not have to be
shared with the carrier network


Customer has a choice of using
any routing protocol

including non IP based (IPX, AppleTalk)


Customers could use
an Ethernet switch

instead of a
router as the CPE


A
single connection

could reach all other edge points
emulating an Ethernet LAN (VPLS)

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

VPLS is defined in IETF

Application

General

Ops and Mgmt

Routing

Security

IETF

MPLS

Transport

Formerly PPVPN

workgroup

VPWS,
VPLS
, IPLS

BGP/MPLS VPNs (RFC
4364 was 2547bis)

IP VPNs using Virtual
Routers (RFC 2764)

CE based VPNs using IPsec

Pseudo Wire Emulation
edge
-
to
-
edge

Forms the backbone
transport for VPLS

IAB

ISOC

As of 2
-
Nov
-
2006

Internet

L2VPN

L3VPN

PWE3

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Classification of VPNs

CPE

Based

Layer 3

MPLS

VPN

Virtual

Router

GRE

IPSec

Layer 3

P2P

VPWS

Ethernet

Frame Relay

PPP/HDLC

ATM/Cell Relay

Ethernet (P2P)

Frame Relay

ATM

Ethernet (P2MP)

Ethernet (MP2MP)

Network

Based

Layer 2

VPLS

IPLS

VPN

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

ATM

AAL5/Cell

PPP

HDLC

Ethernet

FR

L2VPN Models

IP

L2TPv3

Point
-
to
-
Point

ATM

AAL5/Cell

PPP

HDLC

Ethernet

FR

VPWS

Point
-
to
-
Point

Like
-
to
-
Like

Any
-
to
-
Any

Like
-
to
-
Like

L2VPN

MPLS

VPLS/IPLS

Multipoint

Ethernet

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

IP LAN
-
Like Service (IPLS)


An IPLS is very similar to a VPLS except


The CE devices must be hosts or routers not switches


The service will only carry IPv4 or IPv6 packets


IP Control packets are also supported


ARP, ICMP


Layer 2 packets that do not contain IP are not supported


IPLS is a functional subset of the VPLS service


MAC address learning and aging not required


Simpler mechanism to match MAC to CE can be used


Bridging operations removed from the PE


Simplifies hardware capabilities and operation


Defined in draft
-
ietf
-
l2vpn
-
ipls

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

VPLS Components

N
-
PE

MPLS
Core

CE router

CE router

CE switch

CE router

CE router

CE switch

CE switch

CE router

Attachment circuits

Port or VLAN mode

Mesh of LSP between N
-
PEs

N
-
PE

N
-
PE

Pseudo Wires within LSP

Virtual Switch Interface (VSI)
terminates PW and provides
Ethernet bridge function

Targeted LDP between PEs to
exchange VC labels for Pseudo Wires

Attachment CE

can be a switch or router

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010


http://www.grc.upv.es/docencia/tra/

Tema
2:

Tecnologías
LAN.


EtherChannel


Resilient

Ethernet: HSRP

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Etherchannel Concepts

3
9

An Etherchannel combines multiple physical links into a single logical link. Ideal for load
sharing or link redundancy


can be used by both layer 2 and Layer 3 subsystems…

Physical View

Multiple ports are
defined as being
part of an
Etherchannel
group

Logical View

Subsystems running
on the switch only
see one logical link

An Etherchannel can be defined on Ethernet, Fast Ethernet, Gigabit Ethernet or 10 Gigabit
Ethernet Ports

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Etherchannel Concepts

Multichassis EtherChannel (MEC)

4
0

Prior to Virtual Switch, Etherchannels were restricted to reside within the same physical
switch. In a Virtual Switch environment, the 2 physical switches form a single logical network
entity
-

therefore Etherchannels can now also be extended across the 2 physical chassis…

Regular Etherchannel on single chassis

Multichassis EtherChannel across 2 VSL
-
enabled Chassis

Virtual Switch

Virtual Switch

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Resilient Ethernet


How does a workstation get a default gateway?


DHCP:

gives the workstation the default gateway


IRDP (ICMP Router Discovery Protocol):
extension to ICMP that
allows an end
-
station to automatically discover a default
gateway. RPs (Route Processors) periodically generate special
multicast packets that announce the router’s existence to the
clients every 5 to 10 minutes. Multicast packet has the RP’s
address and a life
-
time value. Could take up to 30 minutes.


Proxy ARP:
host dynamically discovers default IP address and
MAC of the default gateway. When default gateway fails, traffic
is dropped. After a lengthy period of time, host will re
-
perform
the Proxy ARP, but in most situations, host will continue using
same failed default gateway.


What happens to the workstation when router fails?


Host can’t communicate with other networks




4
1

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

Solution is HSRP (Hot Standby Routing Protocol)


Cisco
-
proprietary

protocol


Provides Layer 3

redundancy


Transparent to end
stations


RP (Route Processor)
monitors the status of
other RPs and
provides a quick
failover when primary
default gateway fails.


4
2

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

HSRP

4
3

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

HSRP

4
4

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

HSRP Group


A group of 2 or more RPs
that represent a single
default gateway. It has a
virtual IP address and a
virtual MAC address. If
the primary RP fails,
another RP takes over.


One RP can be the
backup for multiple
primary default gateways


Only one RP forwards
data for a LAN.

4
5

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

HSRP Group


Group has the
following type of RPs:


Virtual RP


Active RP


Standby RP


Other RPs


Virtual RP


Provides a

single RP that is available
to end stations.


Not a real RP

the IP and
MAC addresses are not
physically assigned to any
one interface on any of the
RPs in the broadcast
domain


4
6

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

HSRP Group


Active RP


Responsible for forwarding all traffic destined for the Virtual RPs MAC
address.


Elected in an election process

RP with highest priority is active. If
priorities are same, highest IP address wins. Default priority is 100.


Only one active RP per network/
subnetwork
/VLAN


Standby RP


Elected in an election process


Keeps tabs on Active RP by looking for HSRP multicast messages (HSRP
hellos). Hellos are sent by active RP every 3 seconds. If standby doesn’t
hear any hellos for 10 seconds, it promotes itself and becomes the
active RP.


Sends out its own hellos every 3 seconds so that if it fails, one of the
other possible HSRP RPs in the standby group will become the standby.


Only one standby RP per network/
subnetwork
/VLAN


4
7

TECNOLOGÍAS DE RED AVANZADAS


Master

IC
2009
-
2010

HSRP Group


Other HSRP RPs


Listen for hellos from standby and active RPs.


If any end
-
station uses a REAL MAC address of one of the RPs in
the broadcast domain, that specific RP (whether active, standby
or other RP) will process and forward the frame.


Each standby group must have a unique virtual IP
address and a virtual MAC address.


These addresses are unique across different VLANs.


End stations perform an ARP request with the virtual IP
address and get the virtual MAC address of the default
gateway RP.

4
8