Wide Area Networks (WAN) - Synchronous Digital Hierarchy (SDH)

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Wide Area Networks (WAN) -Synchronous Digital
Hierarchy (SDH)

• AAU
• Jens H. Sørensen
• jhaus_at_tdc.dk
• 20 Oktober 2005

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Table of Contents

• Objectives
• Introduction to WANs
• Typical WAN Technologies
• SDH Protocol
• SDH Equipment
• SDH Networks
• SDH Network Management
• SDH Services (partly 2nd part)
• WDM/OTN (2nd part)
• Network availability, restoration and automatic
  protection (2nd part)
• Next/new Generation SDH and relations to IP, ATM,
  WDM, Ethernet (2nd part)
• Network Synchronisation (2nd part)

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Objectives

• Discussion of
• LAN versus WAN, scaleability issues
• WAN technologies, overview
• Typical WANs, examples, SDH
• Relations to networks based on Ethernet/IP/ATM/DSL
  
• Upcoming WAN networks

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What is a WAN?

• Definition of "WAN" according to Webopedia
• A computer network that spans a relatively large
  geographical area.
• Typically, a WAN consists of two or more
  local-area networks (LANs).
• Computers connected to a wide-area network are
  often connected through public networks, such as
  the telephone system. They can also be connected
  through leased lines or satellites.
• The largest WAN in existence is the Internet.

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Introduction to WANs
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Introductionto WANsExampleHigh
CapacityLinks
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Introductionto WANsExamplePhysical
andlogical Links
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Introduction to WANs - scaleability

• Can Ethernet based LANs be connected nationwide
  supporting millions of users?
• Scaleability issues (Ethernet)
• no. of MAC addresses, VLANs, broadcast domains
  (ARP), STP convergence, performance of MAC and
  CSMA/CD under high load, QoS etc..
• Creation of hierarchical networks
• Long distance optical systems
• Scaleability issues (IP)
• routing tables/IP-address aggregation,
  rearrangement of fixed IP-addresses, QoS
• Other technologies are currently used

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Introduction to WANs
TCP, UDP
IP
MPLS
802.3 Ethernet MAC, LLC
ATM
SDH, PDH, DXC 1/0 radio links, satellite, fiber,
copper, WLAN .
10/100/1000 BASET, TX, SX, LX, FX
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Typical WAN Technologies
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WAN Technologies

• WAN capacity levels
• 0 64 kbit/s
• 1 2 Mbit/s (PDH)
• 2 8 Mbit/s (PDH)
• 3 34 Mbit/s/ 45Mbit/s (PDH)
• 4 140/155 Mbit/s (PDH/SDH STM-1, SONET OC-3)
• 5 622 Mbit/s (SDH STM-4, SONET OC-12)
• 6 2,5 Gbit/s (SDH STM-16, SONET OC-48)
• .

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WAN Technologies

• DXC 1/0
• Plesiochronous Digital Hierarchy (PDH)
• Synchronous Digital Hierarchy (SDH, SONET)
• ATM, Frame Relay
• PSTN, ISDN
• Radio Links
• Satellite
• IP
• Ethernet
• ..

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WAN Technologies

• Why not only concentrate on IP/ethernet networks?
• Scaleability issues
• SDH, PDH are essential parts of all incumbent
  operators WAN networks including many new service
  providers
• 2M and STM-N is widely used as leased lines
  including ATM/IP/DSL backbone networks

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SDH Protocol
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SDH Protocol - Multiplexing

• Multiplexing PDH signals
• Plesiochronous multiplexing using bit stuffing
• Multiplexing SDH signals
• Synchronous Multiplexing using Pointer Processing

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SDH på 5 min
SDH ramme, hastigheder og funktionalitet
Time Division Multiplexing (TDM)
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SDH Protocol - Multiplexing

• Multiplexing PDH signals
• Plesiochronous multiplexing using bit stuffing
• Multiplexing SDH signals
• Synchronous Multiplexing using Pointer Processing

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SDH ProtocolAU-4 PointerAdjustment
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SDH Protocol - Multiplexing

• Multiplexing PDH signals
• Plesiochronous multiplexing using bit stuffing
• Multiplexing SDH signals
• Synchronous Multiplexing using Pointer Processing
• Multiplexing Structure
• Adaptation of PDH and other signals

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SDH protocol - Multiplexing Structure
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SDH mapping scheme
Initial mapping
More Multiplexing
Contiguous Concatenation
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SDH Equipment
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SDH Equipment
SDH på 5 min
ADM 4/1
Aggregate
Aggr. Interfaces STM-1/4/(16) Trib. interfaces
2M, 34M, 45M, 140M, STM-1/(4)
Tributary
Interfaces 2M, 34M, 45M, 140M, STM-1,
(STM-4/16) XC matrix scaleable up to 32/128/256
STM-1 equivalent, non-blocking
DXC 4/1
ADM 4/4
Aggregate
Aggr. Interfaces STM-4/16/64 Trib. interfaces
STM-1/4/16 No access to lower order signals
Tributary
REG
Regenerator function
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ADM 4/1 STM-4 example
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ADM 4/4STM-64 example
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SDH Networks
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SDH NetworksHierarchical example
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Network Structures - Pros and Cons
Structure Pros Cons
Chain Fiber effective Simple nodes Low start cost Low connectivity No redundancy P2P upgrade costly
Ring Fiber effective Simple nodes Redundancy Low connectivity P2P upgrade very costly
Mesh High connectivity Redundancy Cost efficient P2P upgrade Fiber consuming Complex nodes
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SDH Networks - example , Routing in a
hierarchical Network
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SDH Networks add on
SDH netstruktur
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International Network structure
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SDH networks - fiber infrastructure
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SDH networks- WDM
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SDH networks- STM-64
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SDH networks- STM-16
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SDH networks - VC-4
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SDH Network node example
SDH netstruktur
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SDH networkOptical cards and application codes

• STM16
• S16.1 (short haul, 1300 nm, 10 km)
• L16.1 (long haul, 1300 nm, 20 km)
• L16.2 (long haul, 1550 nm, 80 km)
• V16.2 (very long haul, 1550 nm, 120 km)
• U16.2 (ultra long haul, 1550 nm, 160 km)
• L16.2 colered interface til WDM rel 1.0
• L16.2 colered interface til WDM rel. 3.0

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Standards
ITU-T

• Concatenation, Protocols etc.
• Link Capacity Adjustment Scheme (LCAS)
• Generic Framing Procedure (GFP)
• Equipment
• Equipment
• Equipment Management Function

G.707 (10/2000)corr 1, corr 2, add
1 G.7042/Y.1305 (11/2001) G.7041/Y.1303
(11/2001) G.783 (02/2001) G.709 (02/2001) G.798
(11/2001)
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SDH Network Management
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SDH Network ManagementNetwork Service
Management View
Bussines Level Management
Costumer administrative systems
Customer acces/ applikationer
Service Level Management

• Funktions
• Provisionering
• Performance
• Assurance
• Alarmmanager

SM funktion 1
SM funktion 2
Network Level Management

• Technical
• administrative
• systems (inventory)
• planning
• modelling
• registration

Network Manager
Network Manager
Subnetwork Manager
Subnetwork Manager
Element Level Management
Element Manager
Element Manager
Network Elements
Network Elements
En netteknologi f.eks. SDH
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SDH Network ManagementElement Manager

• Matrix 48 ports 4/4 non-blocking, dubleret

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SDH Network Management DCN, Data Communications
Network is needed
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SDH Network ManagementNetwork ManagerPoint and
click management
Sub-Network Level
NEs Level
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Fault Management /Service ManagementFilter via
tree view
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SDH Services
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SDH Services

• Leased line Services (fixed dedicated bandwidth)
• 2 Mbit/s, n x 2 Mbit/s
• VC-12, n x VC-12
• 34 Mbit/s, 45 M Mbit/s
• VC-3, n x VC-3
• 140 Mbit/s
• VC-4
• VC-4-4c, VC-4-16c
• Grey fibres / WDM channels
• add-on services
• Alternative routing, Specific routing, automatic
  protection, various Service Level Agreements
  (SLAs)