Transcript A some Aspects of Network Convergence

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
IP CORE NETWORK
SS7
ISDN
Signalling
Gateway
Trunking
Gateway
Residential
Gateway
Access
Network
SIGTRAN
Media Gateway
Controller
MEGACO/
MGCP
SOFTSWITCH
SIP-T
MEGACO/
MGCP
Access
Gateway
Media Gateway
Controller
MEGACO/
MGCP
IP PHONES
VARIOUS TYPES OF SUBSCRIBER AND NETWORK MGs
Vaculík Martin 2006
Access Technologies and convergence
• MEDIA GATEWAY TYPICAL ARCHITECTURE
(LITESPAN 1540 ALCATEL)
SERVER BUS
2X16Mb/s
16XE1
NARROWBAND
CONTROLLER
STM1/4
TRANSPORT
SDH/PDH
BROADBAND
CONTROLLER
NARROWBAND TDM BUS 2 X 51 Mb/s
BROADBAND ATM
BUS 2 X 155 Mb/s
4xE1- IMA, E3
ETH10/100BaseT, 100FX
BB LINE
CARDs
ETHERNET
BRIDGE
ETH10/100BaseT
TEST,
ALARM,
RINGER.
VoIP
SERVER
ADSL
SHDSL
IMA E1
NB LINE
CARDs
POTS
ISDN
ANALOG LL
DIGITAL LL
HDSL
SHDSL
Access Technologies and convergence
• KEY FEATURES:
• SUBSCRIBERs POTS, UK/2B1Q and U2M 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
METRO
ETHERNET
TERMINAL
CO
HIGHER LAYERS
IP
IP
IP
ETHERNET
ETHERNET
HIGHER LAYERS
CPE
IP
ETHERNET
Physical Layer
Physical
Layer
Physical
Layer
UNI
Physical
Layer
Physical
Layer
ETHER
NET
Physical
Layer
ETH,
ATM,...
Physical
Layer
Access Technologies and convergence
UNI PHYSICAL LAYER:
ETHERNET over FIRST MILE (EFM)
EFM OVER COPPER
MAC Full duplex
ETHERNET Media Independent Interface
1000BASE-X
PHY
FIBRE
PMD
•
2Base-TL
SHDSL, 2+2 Mb/s, 2700 m
EoxDSL
PHY
EPON
PHY
•
COPPER
PMD
FIBRE
PMD
• 100/1000Base-X
10Base-TS
VDSL, 10+10 Mb/s, 750 m
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
u
u
CIR meet
TOKENS
CIR
RATE
TOKENS
>CBS
CBS
EIR
RATE
>EBS
EBS meet
Discard
DISCARD
<= CBS
EBS
<=EBS
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
VLAN Tag (Optional)
CESoE Frame
0x88D8
CESoE Service
Structure:
20 bits
Emulated CIrcuit iDent.
L- Near End ERR
0x102
Reserved
R - Far End ERR
4 1 1 2 2
6
16
CESoE Control Word
M - ERR Code
RES L R M FRG LEN SqN
FRG - Fragment Status
RTP (Optional)
LEN - Length of Stuffing
TDM PAYLOAD
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 datarate 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 blockcoded client signals
Transport technologies and convergence
Encapsulation of frame/packet based data flow
ETH PHY MAC
IP Payload
Core HDR Payload HDR GFP Payload
Flag
Addr Ctrl
Ethernet Frame
FCS
FCS
PPP type PPP Info
GFP Frame
FCS
PPP/HDLC Frame
PTI
PFI EXI
User Payload Identifier
Type of HEC
Spare
GFP Extension HEC
PLength HDR Check Payload HDR
PAYLOAD
FCS
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:
FRAME
Header
LABEL (20)
MPLS
Header
Exp (3)
IP Header
S (1) TTL (8)
DATA
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:
• Packet-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
Link Capacity
DTM over SDH
125us
Frame
DTM over WDM
Frames
Channel
B
CONTROL
Channel
A
Slots
Questions?
Vaculík Martin 2006