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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
TrunkingGateway
SS7
ISDN
AccessNetwork
SignallingGateway
AccessGateway
ResidentialGateway
Media GatewayController
Media GatewayController
SIP-T
MEGACO/MGCP
SIGTRAN
MEGACO/MGCP
MEGACO/MGCP
IP CORE NETWORK
SOFTSWITCH
IP PHONES
VARIOUS TYPES OF SUBSCRIBER AND NETWORK MGs
Vaculík Martin 2006
Access Technologies and convergence
• MEDIA GATEWAY TYPICAL ARCHITECTURE (LITESPAN 1540 ALCATEL)
16XE1
4xE1- IMA, E3
STM1/4
ETHERNETBRIDGE
ETH10/100BaseT
NARROWBAND TDM BUS 2 X 51 Mb/s
BROADBAND ATMBUS 2 X 155 Mb/s
TRANSPORTSDH/PDH
NARROWBANDCONTROLLER
BROADBANDCONTROLLER
ETH10/100BaseT, 100FXBB LINECARDs
NB LINECARDs
TEST,ALARM,RINGER.
ADSLSHDSLIMA E1
POTSISDNANALOG LLDIGITAL LLHDSLSHDSL
VoIPSERVER
SERVER BUS2X16Mb/s
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
TERMINAL
CPEHIGHER LAYERS
IP
ETHERNET
Physical Layer
IP
ETHERNET
PhysicalLayer
PhysicalLayer
IP
ETHERNET
PhysicalLayer
PhysicalLayer
HIGHER LAYERS
IP
ETHERNET
PhysicalLayer
PhysicalLayer
ETH,ATM,...
METROETHERNET
COUNI
Access Technologies and convergence
UNI PHYSICAL LAYER: ETHERNET over FIRST MILE (EFM)
ETHERNET Media Independent Interface
MAC Full duplex
1000BASE-XPHY
EoxDSLPHY
EPONPHY
FIBREPMD
COPPERPMD
FIBREPMD
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 PONTOTAL CAPACITY UP TO 1 Gb/sAPPROX. 1 Mb/s at UNI, 10/20 km RANGE
Access Technologies and convergence
ETHERNET VIRTUAL CONNECTION SERVICEETH FRAME TRANSMITTED TRANSPARENTLY
(SAME MAC ADDR., SAME PAYLOAD)
MULTIPOINT: ETHERNET LAN SERVICEPOINT-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 convergenceEthernet virtual connection QoS
• BANDWITH PROFILE CONTROL
TOKENS
CIRRATE
EIRRATE
CBS
EBS
TOKENS
>CBS
DISCARD
>EBS
<= CBS
<=EBS
TWO RATE TREE COLOR Mechanism
DUAL LEAKY BUCKET
CIR meet
EBS meet
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 lossG.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 msPacket 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 ERRR - Far End ERRM - ERR CodeFRG - Fragment StatusLEN - Length of Stuffing VLAN Tag (Optional)
0x88D8 CESoE Service
20 bits Emulated CIrcuit iDent.
0x102 Reserved
4 1 1 2 2 6 16
RES L R M FRG LEN SqNCESoE Control Word
RTP (Optional)
TDM PAYLOAD
Access Technologies and convergence
Voice over DSL -drive toward voice/data convergence - Step 1
POTS/ISDN/DATA services mixed via IADIAD 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 emulationVoice 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 IPIAD can remain unchanged, LEX replaced by Call
server - SoftswitchT-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
Core HDR Payload HDR GFP Payload
Ctrl
FCS
Flag Addr PPP type PPP Info FCS
FCSETH PHY MAC IP Payload Ethernet Frame
PPP/HDLC Frame
GFP Frame
Payload HDR
User Payload IdentifierType of HECSpareGFP Extension HEC
PLength HDR Check PAYLOAD FCS
PTI PFI EXI
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 breakdownThe 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 RoutingComponents: • Edge Label switch routers (ELSR) • Core Label Switch Routers (CLSR)
MPLS Label:
FRAMEHeader
IP HeaderMPLSHeader
DATA
TTL (8)LABEL (20) Exp (3) S (1)
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 CreationLabel 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 technologiesTransport Layer:• Physical sublayer (Fibres, Optical Muxes,
wavelengths, )• Logical sublayer - Logical connections
Source to Destination Mode, constitued by LSR
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 SWITCHINGLine capacity shared into the frames 125 usSlot 64 bits, 512 kb/sChannel - n x slot, n x 512 kb/sDynamic Bandwidth allocation n x 512 kb/s
125usFrame
CONTROL
ChannelA
ChannelB
Link Capacity
Slots
Frames
DTM over SDH
DTM over WDM