Access Technologies and convergence

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30 Οκτ 2013 (πριν από 3 χρόνια και 9 μήνες)

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Access Technologies and
convergence


Access technologies plays an important
role within network convergence


Stage 1: Integration of PSTN /ISDN/IP
terminals and additional support of
broadband data services


Stage 2: All
-
IP based, unified interface
to all services and terminals


Vaculík Martin 2006

Access Technologies and convergence

Stage 1 main Feature


Shifting the subscriber’s port on the edge
on Network


All media and signalling conversion
performed in distributed Media gateways
MG


MGs
controlled

by MG controller(s)


MG use IP connectivity via ETH/PDH/SDH


Interworking to the existing ISDN via MG

Vaculík Martin 2006

Access Technologies and convergence

VARIOUS TYPES OF SUBSCRIBER AND NETWORK
MGs

Vaculík Martin 2006

Access Technologies and convergence


MEDIA GATEWAY TYPICAL ARCHITECTURE
(LITESPAN 1540 ALCATEL)

Access Technologies and convergence


KEY FEATURES
:


SUBSCRIBERs POTS,
U
K/2B1Q


and

U
2M

Interface


ADSL as a STANDARD EQUIPMENT OF PORTS


(SLOVAKIA: NOVADAYS LIMITED TO APPROX. 3/0.5
Mb/s DUE TO SELF
-
INSTALATION.......)


VoDSL SUPPORT


ISDN NETWORK VIA V5.1 AND V5.2


NGN NETWORK SIDE: FROM N x E1 copper TO
STM

1
/4 optical


MEGACO/H.248 AND IPoA


ADDRESS TRANSLATION POTS/IP
(VoIP SERVER)


Access Technologies and convergence

STAGE 2
-

ALL IP BROADBAND ACCESS


REDUCING PPP AND/OR
ATM over

ADSL

METRO
-
ETHERNET:


A VARIOUS PROTOCOLS POSSIBLE INSIDE,


ONLY IP on THE UNI SUBSCRIBER SIDE


Access Technologies and convergence

UNI PHYSICAL LAYER:

ETHERNET over FIRST

MILE (EFM)

EFM
OVER COPPER



2Base
-
TL



SHDSL, 2+2 Mb/s, 2700 m



10Base
-
TS



VDSL, 10+10 Mb/s, 750 m



100/1000Base
-
X



sm FIBRE, DIPLEX/DUPLEX,


10 km



ETHERNET OVER

PON

Access Technologies and convergence

EPON:

CLASSICAL MULTIPOINT TDM/TDMA BASED PON

TOTAL CAPACITY UP TO 1 Gb/s

APPROX. 1 Mb/s at UNI, 10/20 km RANGE

Access Technologies and convergence

ETHERNET VIRTUAL CONNECTION SERVICE

ETH FRAME TRANSMITTED TRANSPARENTLY
(SAME MAC ADDR., SAME PAYLOAD)

MULTIPOINT:


ETHERNET LAN SERVICE

POINT
-
TO
-
POINT:
ETHERNET LINE SERVICE


BEST EFFORT
or



GUARANTEED QoS


Committed

Information

Rate

CIR


Committed

Burst

Size

CBS


Excess

Information

Rate

EIR


Excess

Burst

Size

EBS


Jitter,

Packet

Loss,

Delay





Access Technologies and convergence

Ethernet virtual connection QoS


BANDWITH PROFILE CONTROL


TWO RATE TREE
COLOR
Mechanism

DUAL LEAKY
BUCKET

u

CIR
meet

u

EBS meet

u

Discard



Access Technologies and convergence

Circuit Emulation Service over Ethernet
(CESoE)


Synchronous traffic emulation


TDM Access Line Service
(Access to ISDN)


TDM Line Service
(Private TDM Network)


E Line
(Private Circuit emulation)


Hybrid Line


Non structured(transparent)


Structured Mode (only Payload, no alarms)

Access Technologies and convergence

Technical requirements:

Low and constant delay
(up to 30 ms e2e)

Min. Packet loss

G.826 ITU Rec.: E1: ES =7E
-
3/4E
-
2
;

SYNC Clock & Timing reconstruction


Packetisation delay
-

1 ms
E1
-

256 B, E3
-

1024 B

Network delay
-

up to 25 ms
(no EC necessary)

Jitter delay
-

up to 10 ms

Packet Loss <
1E
-
6

to reach G.826 ES values



Access Technologies and convergence

Timing reconstruction
-

TDM Output lock to:


TDM Input


External Clock gen.


Free running Oscillator


Ethernet input


CESoE Frame


Structure:

L
-

Near End ERR

R
-

Far End ERR

M
-

ERR Code

FRG
-

Fragment Status

LEN
-

Length of Stuffing


Access Technologies and convergence

Voice over DSL

-
drive toward voice/data
convergence

-

Step 1

POTS/ISDN/DATA services mixed via IAD

IAD main functions:


Termination of the user interfaces (POTS, ISDN)


ATM AAL2 (de)multiplexing


Voice handling function (compression, echo
cancellation)


Generation of (POTS) or relaying DSS1 signalling
towards the voice gateway


Management from the gateway via an in
-
band
interface

Access Technologies and convergence

Transfer mode
-

ATM AAL2 Loop emulation

Voice switching
-

TDM switching network or
Call Server (Softswitch)


DATA

VOICE

Access Technologies and convergence

Voice gateway functions:


Termination of the voice circuits


ATM AAL2 (de)multiplexing to/from a single ATM
VC


Voice handling (compression, echo cancellation)


IAD to voice gateway signalling termination and
call control


On
-
demand traffic concentration of the voice
channels


Connectivity to a LEX via an open interface V5.x


Management of the IADs via an in
-
band interface


Access Technologies and convergence

All Digital Loop:

NT
&VGW Integration


ISDL, ADSL or SHDSL access


So/a,b/10BaseT interfaces


emergency power feeding


Wi
-
Fi

AP can be integrated

Step 2: Voice over IP

IAD can remain unchanged, LEX replaced by
Call server
-

Softswitch

T
-
Com Slovakia: „
I‘m calling over IP
“ service,
Virtual
“IP Office”

service
-

068xxxx
numbering, approx. 40 % of the analog line
cost, unbounded access




Transport technologies and convergence


Present Core transport network:


SDH up to STM 16/64


TDM/ATM/IP mapping


High resilience and short recovery time
(<50ms)


perfect OAM and network management


99.999 % Reliability (5 min per Year outage)

Continuous upgrade of properties, e.g.:


Generic Framing Procedure


Virtual Concatenation


Link Capacity Adjustment Scheme

Transport technologies and convergence

Generic Framing Procedure

-

generic
mechanism to transport any client signal (IP/PPP,
Ethernet MAC, Fibre Channel,...) over fixed data
-
rate optical channels


point
-
to
-
point and ring applications


length/HEC
-
based frame delineation mechanism

Two mapping modes:


Frame
-
mapped GFP
-
F: maps the entire client
frame into one GFP frame


Transparent
-
mapped GFP

T: transport of block
-
coded client signals



Transport technologies and convergence

Encapsulation of frame/packet based data flow


Transport technologies and convergence

Concatenation
-

a more efficient way to broke a
fix Container capacity assignment

Arbitrary contiguous concatenation:


custom sized bandwidth but the network


supports this bandwidth as a single entity


all intermediate nodes must support this feature


Virtual Concatenation:
custom sized bandwidth but


Virtual containers create a LOGICAL group and


can be routed independently


Traffic (de)segmentation on a customer terminals

Transport technologies and convergence

Link Capacity Adjustment scheme:

Capacity adjustment possible during the
transport without traffic breakdown

The bandwidth tuning based on:


Quality of Service (QoS) parameters


Bandwidth on demand (time
-
of
-
day
demands, seasonal,...)


Load Balancing


to split the traffic load
between different points in the network


Inherently bursty traffic transmission

Transport technologies and convergence

Support for LCAS:

located in the VC source/sink adaptation functions only


a two
-
way handshake signalling protocol
used


Synchronisation of changes:
a control packet
sequence of H4 Path overhead bytes


control packet describes the state of the link
during the next control packet


Service Level Agreements (
SLAs)

guarantee



Controlled by Network and Element
Management Systems (NMS/EMS)

Transport technologies and convergence

1GBE or 10GBE
:

almost all parameters worst
than SDH (exception
-

No IP/frame mapping
necessary)

Restoration techniques in std.IP networks:

from several seconds to minutes ....


automatic protection switching (APS)


and virtual router redundancy protocol (VRRP)

continuously exchange of the redundant
forwarding table

QoS

supported in the Integrated Services (IntServ)
paradigm by means of the Resource ReSerVation
Protocol (RSVP)


Transport technologies and convergence

Label switching
-

more effective routing &
redundancy offering tool

Packet&Frame L2 Switching/L3 Routing

Components:


Edge Label switch routers (ELSR)


Core Label Switch Routers (CLSR)


MPLS Label:



Transport technologies and convergence

Labels based on:


Source router routing table


Source distinguishing (via Route
Distinguisher)



IP / Multicast Address


SLA/QoS Parameters

Put into Packet Label Stack

Forwarding Equivalence Class Creation

Label Information Base (Labels and FEC
bindings)


Distributed over Label Distribution Protocol

Transport technologies and convergence

Generalized Multi
-
Protocol Label Switching
(GMPLS) protocol suite (RFC 3471)


extending the label switching from
packet/cell/frame
-
switched technologies to
connection
-
oriented technologies

Transport Layer:


Physical sublayer (Fibres, Optical Muxes,
wavelengths, )


Logical sublayer
-

Logical connections
Source to Destination Mode, constitued by
LSR


Transport technologies and convergence

Transport technologies and convergence

GMPLS encompasses:



P
acket
-
switching
-
capable devices (IP/MPLS routers
and layer
-
2 devices (ATM, FR, Ethernet)),



Time division multiplexing
-
capable devices (SDH)



Reconfigurable Add/Drop Multiplexers (RADMs)
and Digital Cross
-
Connects (DXC),



Lambda (or wavelength) switching
-
capable devices
(Reconfigurable Optical ADMs (ROADMs) and Optical
Cross
-
Connects (OXCs),



Waveband
-
switching
-
capable devices (WaveBand
Cross
-
Connects, WBXC),



Fiber switching
-
capable devices (Fiber XC, FXC).


Transport technologies and convergence

DTM
-

DYNAMIC CIRCUIT SWITCHING

Line capacity shared into the frames 125 us

Slot 64 bits, 512 kb/s

Channel
-

n x slot, n x 512 kb/s

Dynamic Bandwidth allocation n x 512 kb/s


DTM over SDH

DTM over WDM


Questions?

Vaculík Martin 2006