Automatic Switched Optical Networks - PowerPoint PPT Presentation

1 / 30
About This Presentation
Title:

Automatic Switched Optical Networks

Description:

(re-active) the actual traffic demand. It is an inter layer network process ... link should be modified or released, based on the network provider's policy ... – PowerPoint PPT presentation

Number of Views:490
Avg rating:3.0/5.0
Slides: 31
Provided by: maarten3
Category:

less

Transcript and Presenter's Notes

Title: Automatic Switched Optical Networks


1
Automatic Switched Optical Networks
  • "Multi-Layer Network Architecture"

Maarten Vissers Consulting Member of Technical
Staff Lucent Technologies email
mvissers_at_lucent.com
Generalised MPLS Summit, October 2001
2
Contents
  • Introduction
  • Network
  • Transport Plane's View
  • Control Plane's View
  • Traffic Network Engineering
  • Interfaces
  • Control Plane(s)

This presentation includes animated slides. It is
best viewed in "slide show" mode.
This presentation includes some notes in the
notes pages.
3
Introduction
  • Automatic Switched Transport Network (ASTN) is
    ITU-T's work item to introduce switching
    capabilities in any layer network
  • Requirements are specified in Rec. G.807
    (05/2001)
  • Architecture for the "Optical Network" (i.e. OTN,
    SDH/SONET) ? Rec. G.8080 (ex. G.ason)
  • Distributed Call and Connection Management (DCM)
    ? Rec. G.7713
  • First part is a protocol independent
    specification
  • Generalized Automatic Discovery Techniques ? Rec.
    G.7714
  • Architecture and specification of data
    communication network (DCN)? Rec. G.7712
  • Other recommendations will follow to address
    further aspects of switched networks e.g.
    routing, link resource management
  • This presentation focuses on the "multi-layer"
    architecture

Note - ITU-T based terminology is used (Rec.
G.805, G.806, G.ason)
4
Network and its "Network Elements"
Note - LOVC and HOVC roles can be played by
several layer networks
5
Network - Layer Networks
6
Network - Layer NetworksClient/Server
relationships
LOVC and HOVC roles can be played by the layer
networks listed
7
Layer Network - Transport Plane's View
  • Ports
  • Support Links via adaptation to server layer
  • Adapt client signals
  • Monitor native client signals
  • Determine QoS to verify SLAs
  • Links
  • Represent Bandwidth available to Routing
  • Define Topology of layer network
  • Addition, Deletion, Sizing
  • Fabrics
  • Flexibility points
  • Not always present
  • fixed connections
  • Possible restricted connectivity
  • e.g. no Wavelength or Time Slot Interchange

8
Transport Plane - Ports
  • 5 Port Types
  • Termination/Monitoring and Adaptation
    functionality
  • Spanning single or multiple layer networks
  • Monitoring service signal
  • Non Intrusive Monitor (NIM)
  • Tandem Connection Monitor (TCM)
  • Port Management
  • Reporting mode
  • Connectivity verification
  • Error detection
  • Protection Switching

To/From USER
To/From USER
9
Transport Plane - Connections
  • Native
  • port B to port B'
  • Hybrid
  • any other, e.g. B to A', B to C', A to B', ...
  • Client
  • port A to port A'
  • port C to port C'

10
Layer Network - Control Plane's View
  • SNPs
  • Abstraction of CP and TCP CTP and TTP
  • Extremity of Sub Networks
  • Extremity of Links
  • Links
  • Represent Bandwidth available to Routing
  • Between two SNP Pools
  • Define Topology of layer network
  • Sub Networks
  • Abstract. of specific Char. Information Routing
    Domain
  • Fabric is lowest level Sub Network
  • Between two or more SNP Pools
  • Degenerate SN
  • set of fixed connections

11
Control Plane - Sub NetworkSub Network
Controllers
  • Each sub network has an associated Sub Network
    Controller (SNCr)
  • SNCrs within one layer network communicate with
    each other for the purpose of connection control
    (routing)
  • SNCrs can be located in 3 different nodes
  • network element (NE)
  • local processor (LP)
  • centralised processor (CP)
  • SNCrs of client and server layer networks do not
    communicate with each other
  • if communication between a layer network and its
    server layer network is required, it is performed
    via a third component

12
Control Plane - Sub NetworkSNCr Hierarchy
  • SNCrs within one layer network can be organised
    with peering relationship and/or hierarchical
    relationship

13
Control Plane - Sub NetworkSNCr Communications
  • All SNCrs in a network communicate via the
    Signalling Communication Network (SCN)
  • SCN is a application of the general Data
    Communication Network (DCN)
  • SCN is an IP-based transport network
  • SCN uses Routers and Router functions within
    Transport NEs
  • SCN has build in protection switching
  • Backup connections between SNCrs must be present
    to guarantee restoration performance when e.g. a
    cable is cut
  • MPLS may be deployed to implement protected
    connections in the SCN
  • MPLS OAM (draft Rec. Y.1710/Y.1711)
  • MPLS Protection Switching (draft Rec. Y.1720)

14
Control Plane - Sub NetworkSNCr Communications
IP/MPLS signalling for DCN/SCN
ODUk signalling
LOVC signalling
HOVC signalling
15
Control Plane - (Sub) NetworkCall Controller
  • Call Controllers are located at the "edges" of
    the Network
  • Call Controllers negotiate call details with the
    User requesting the call
  • Once a call is accepted, the Call Controller
    forwards the call request to a Sub Network
    Controller in its layer network
  • Call Controllers can be located in a
  • network element (NE)
  • local processor (LP)
  • Call Controllers of client and server layer
    networks do not communicate with each other
  • Call Controllers of a layer network do not
    communicate with SNCrs in its client or server
    layer networks

16
Control Plane - LinksParallel and Serial
composition
  • Parallel composition represents partitions within
    the subnetwork e.g. component links for
  • one or more Virtual Private Networks (VPN)
  • public network
  • shared risk group
  • similar propagation delay
  • similar administrative cost
  • similar server layer protection type
  • adaptive or fixed rate

17
Control Plane - LinksParallel and Serial
composition
  • Serial composition represents link connections
    through
  • non-switched subnetwork
  • switched third party subnetworks providing nailed
    up soft permanent connections between SNPs at
    edges

18
Traffic Network Engineering
  • Traffic engineering (TE)
  • Put the traffic where the bandwidth is
  • (Sub-)second/minute time scale
  • Network Engineering (NwE)
  • Put the bandwidth where the traffic is or is soon
    expected to be
  • 15 minute/hour/day/week time scale
  • Network Planning (NP)
  • Put the equipment, fibers and bandwidth where the
    traffic is expected to be in the future
  • Month/quarter/year time scale

19
Traffic Engineering (TE)
  • The process concerned with optimally routing of
    signals over existing links in a layer network
  • More specific Optimally assigning available
    bandwidth to requests (to the network) for
    bandwidth.
  • It is an intra layer network process
  • TE process in each layer network
  • discovers the links created by network planning
    and engineering
  • advertises the links and their bandwidth
    utilisation
  • manages (set-up, release, modify) connections in
    the layer network i.e. processes incoming calls
    for native and client connections
  • restores high grade connections on signal fail
    or signal degrade of the connection
  • It is implemented by the Sub Network Controllers
    within the layer network

20
Network Engineering
  • The process concerned with optimally selecting
    topology and bandwidth in a layer network, based
    on
  • (pro-active) traffic demands expected between any
    two locations in the network and
  • (re-active) the actual traffic demand
  • It is an inter layer network process
  • NwE process in each layer network
  • advertises the nodes and their ports within the
    layer network
  • monitors the layer network and determines if/when
    a new (topological) link should be added or an
    existing link should be modified or released,
    based on the network provider's policy
  • determines best set of connections between ports
    in the layer network
  • requests those connections to be set up by its
    server layer networks i.e. generates outgoing
    calls for client connections
  • It is implemented by the (distributed) Network
    Engineering Controllers (NEC) within the layer
    network

21
Network Planning
  • The process concerned with optimally selecting
    equipment, fiber medium and bandwidth based on
  • expected traffic growth, also taking into account
    inherent uncertainties
  • service levels (availability, service delivery
    times)
  • total network cost (capex and opex)
  • NP process is a multi layer network process
  • Physical fiber infrastructure and topology
  • Logical architecture and topology
  • hierarchical levels
  • ring / mesh / star
  • granularity
  • It is implemented by off-line planning algorithms
    and tools
  • quantitatively evaluate alternatives
  • dimensioning
  • cost calculations, business modelling

22
Network with SNCr's, CallC's and NEC's
23
Interfaces - Types
  • Interior Network Node Interface (I-NNI)
  • within operators administrative domain
  • supports set up and control of connections across
    ASON network
  • presents full topology/routing information
  • Exterior Network Node Interface (E-NNI)
  • between operator administrative domains
  • between I-NNI areas within operator's admin
    domain (scalability)
  • supports set up and control of connections across
    ASON network
  • presents reachability and summarized address
    information
  • User to Network Interface (UNI)
  • between user and network domains
  • supports call requests from User
  • Layer Network Interface ? also a UNI
  • between client and server layer networks
  • supports call request from client layer's network
    engineering controller

24
Interfaces - Layer Networks Links
  • Each component link in a layer network has an
    associated Interface type (I-NNI, E-NNI, UNI)
  • One link with multiple component links may have
    multiple interface types associated
  • e.g. 1 component link with UNI, and 3 components
    link with I-NNI
  • A physical interface may encompass multiple layer
    networks
  • e.g. STM-4 interface may support HOVC and LOVC
    layer networks
  • A link in one of the layer networks in the
    physical interface is independent of a link in
    one of the other layer networks in the physical
    interface
  • e.g. HOVC link may be a UNI and LOVC link may be
    a E-NNI

25
Interfaces - Layer Networks LinksExample
LOVC PN
LOVC Link
LOVC VPN 1
UNI
I-NNI
LOVC VPN 2
I-NNI
STM-N Physical Interface
HOVC Link
PC
HOVC PN
HOVC Permanent Connection non-switched
UNI
I-NNI
Component Link
HOVC VPN
PN Public Network VPN Virtual Private Network
26
Control Plane(s) - 1 or N
  • How many control planes are present in an ASON
    network?
  • Just a matter of semantics...
  • 1 control plane with N TE instances (1 per layer
    network)
  • N control planes (1 per layer network) with 1 TE
    instance per control plane
  • i.e. do you prefer to wrap the box, or do you
    prefer to wrap each piece within the box
    individually

27
Control Plane(s) - Implementation
  • The ASON specification is a functional
    specification
  • Multiple implementation are envisaged to concur
    in the network e.g. components in an
    implementation
  • are identical to components in functional
    specification
  • encompass multiple components in functional
    specification
  • Control plane implementations targeted for small
    networks may "integrate" functional components
  • Control plane implementations targeted for large
    networks may follow more closely the functional
    components structure
  • One size doesn't fit all

28
  • THANK YOU

29
Layer Network Overview
30
Traffic EngineeringSNCr functions
0..N
Policing Agent
0..N
1..N
Policing Agent
Neighbour Discovery
Route Table Construction
Route Table Construction
Neighbour Discovery
0..N
Link Resource Manager
0..N
Link Resource Manager
Route Table
Route Table
Route Table Update
0..N
0..N
Connection Admission Control
Connection Admission Control
Connection Controller
Connection Controller
Connection Point Status
SubNetwork Controller
Protocol Controller
Write a Comment
User Comments (0)
About PowerShow.com