Post on 12-Jan-2016
description
Optical Control Plane,Optical/IP integration Concepts
and Issues
Optical Control Plane,Optical/IP integration Concepts
and Issues
Greg Bernstein
Gregb@ciena.com
Greg Bernstein
Gregb@ciena.com
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Issues and Requirements…Issues and Requirements…
• Standards are emerging for control of optical networks…– Primarily aimed at service providers and carriers
• Some of these efforts were started under vastly different circumstances than the optical networking industry now faces
• Some of these control standards were ahead of any interoperability standards at the optical layer
• Good IP/Optical integration would require at least:– Information about the optical network topology/resources
– Timely IP level traffic statistics
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Also see: “Control Plane Design for Reliable Optical Networks”, IEEE Communications Magazine, Feb., 2002, by folks at AT&T Labs. Also see http://www.networkwatch.rhk.com/ShowAnalysis.asp?analysisId=106
Also see: “Control Plane Design for Reliable Optical Networks”, IEEE Communications Magazine, Feb., 2002, by folks at AT&T Labs. Also see http://www.networkwatch.rhk.com/ShowAnalysis.asp?analysisId=106
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Goals: Automation of Optical Control FunctionsGoals: Automation of Optical Control Functions
• Automatic Neighbor Discovery– Allows a node to determine the identity of each
neighboring node and the set of links that connect them
• Topology and Resource Status Dissemination– Allows every node to automatically discover the
complete network topology and resources
• Signaling for Connection Provisioning
– Allows the establishment and restoration of a path from one end of the connection
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Optical Control Plane FunctionsOptical Control Plane Functions
4. Path Calculation (NE-based or EMS-based)4. Path Calculation (NE-based or EMS-based)
NETWORK MGMT PLANENETWORK MGMT PLANE
1. Neighbor Discovery1. Neighbor Discovery
2. Global Topology Dissemination2. Global Topology Dissemination
CONTROL PLANECONTROL PLANE
Inventory & Resource ManagementInventory & Resource Management
Dynamic ProvisioningDynamic Provisioning 5. Establish Connection5. Establish Connection
DATA PLANEDATA PLANE
3. Connection Request3. Connection Request
OUNIOUNIUserUser UserUser
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Standards Bodies and OrganizationsStandards Bodies and Organizations
Charter: Global Telecom Architecture and StandardsMembership Fee: minimum $18,900/yr (31,500 Swiss Fr.)No. of Members: 189 Member States + 434 Sector Members
Member Organizations: • Global Service Providers• PTTs, ILECs, IXCs• Telecom equipment vendors• Governments (e.g., US State Department)
Charter: Global Telecom Architecture and StandardsMembership Fee: minimum $18,900/yr (31,500 Swiss Fr.)No. of Members: 189 Member States + 434 Sector Members
Member Organizations: • Global Service Providers• PTTs, ILECs, IXCs• Telecom equipment vendors• Governments (e.g., US State Department)
Charter: Evolution of the Internet (IP) ArchitectureMembership Fee: NoneMembership: Individuals – community model
Active Participants: • ISPs• Service Provider IP Divisions • IP/Ethernet Vendors
Charter: Evolution of the Internet (IP) ArchitectureMembership Fee: NoneMembership: Individuals – community model
Active Participants: • ISPs• Service Provider IP Divisions • IP/Ethernet Vendors
Charter: Development of Optical Networking Products and ServicesMembership Fee: $8000/yrNo. of Members: 312 Principal Members
Member Organizations: • PTTs, ISPs, ILECs, IXCs • Optical Networking Vendors
Charter: Development of Optical Networking Products and ServicesMembership Fee: $8000/yrNo. of Members: 312 Principal Members
Member Organizations: • PTTs, ISPs, ILECs, IXCs • Optical Networking Vendors
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Control Plane InterfacesControl Plane Interfaces
User AdminDomain
User AdminDomain
Provider A Admin Domain
Provider C Admin DomainUNI UNI
E-NNI
E-NNI
Provider B Admin Domain
firewall
firewall
L2/L3
L2/L3
LoadBalancer
LoadBalancer
firewall
firewall
L2/L3
L2/L3
LoadBalancer
LoadBalancer
Domain A1 Domain A2
E-NNI
I-NNI
I-NNII-NNI
Provider A has dividedtheir network into multiplecontrol domains (e.g., vendor, geographic, technology, political, etc.)
Provider B’s network is a single control domain
UNI: operations between end-user and service provider admin domainsE-NNI: multi-control domain operation for a single service provider; multi-control domain operation among different service providersI-NNI: intra-control domain operation
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Why do Neighbor Discovery?Why do Neighbor Discovery?
• Allows automatic inventorying of physical links between nodes– Can determine inconsistent physical wiring
• Allows automatic identification of node-pair neighbors
– Useful for path computation and signaling
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Neighbor Discovery at which layer? Between which layer?Neighbor Discovery at which layer? Between which layer?
PLR PLR STE LTE PTESTELTEPTE
STE-STE neighbor discovery
LTE-LTE neighbor discovery
PLR-PLR neighbor discoveryDefinitions
PLR - Physical Layer Regenerator
STE - Section Terminating Equipment
LTE - Line Terminating Equipment
PTE - Path Terminating Equipment
Definitions
PLR - Physical Layer Regenerator
STE - Section Terminating Equipment
LTE - Line Terminating Equipment
PTE - Path Terminating Equipment
STE-LTE neighbor discoveryPLR-STE neighbor discovery
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Optical Link State RoutingOptical Link State Routing
• A way to discover and disseminate topology and resource information independent of the EMS
• Offloads the EMS from performing this task
• Makes this information available at every node enhanced robustness in the event of major network problems
• Timely updates of changes to all nodes
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Routing Roles:Routing Roles:
• Discovery portion
– Hello protocol (assumes data and control planes are the same)
– Not applicable, in general, to optical networks
• Topology Dissemination
– Information concerning nodes (including reachability) and links in the network
– Want and need more information for optical networks
• Route Computation
– To give IP forwarding table (heavily constrained due to hop-by-hop forwarding paradigm)
– Overly simplistic for optical networks
Traditional IP link state IGPs (OSPF, IS-IS)Traditional IP link state IGPs (OSPF, IS-IS)
Acronyms: IP (Internet Protocol), IGPs (Internal Gateway Protocols), OSPF (Open Shortest Path First), IS-IS (Intermediate System to Intermediate System)
Acronyms: IP (Internet Protocol), IGPs (Internal Gateway Protocols), OSPF (Open Shortest Path First), IS-IS (Intermediate System to Intermediate System)
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Example Network ViewExample Network View
Protection: 4F-BLSR; SRLG: 1, 17Capacity: 16 STS-1, 4 STS-3, 1 STS-12c
Protection: 4F-BLSR; SRLG: 101, 880Capacity: 16 STS-1, 4 STS-3c, 1 STS-12c
Protection: 4F-BLSR; SRLG: 5, 580Capacity: 28 STS-1, 8 STS-3c, 2 STS-12c
Protection: 1:N, N = 3; SRLG: 237Capacity: 102 STS-1, 30 STS-3c, 4 STS-12c, 1 STS-48c
Protection: 1:N, N = 2; SRLG: 138Capacity: 105 STS-1, 33 STS-3c, 8 STS-12c, 2 STS-48c
Protection: 1:N, N = 1; SRLG: 80, 12Capacity: 97 STS-1, 31 STS-3c, 6 STS-12c, 2 STS-48c
NE 1NE 1
NE 2NE 2
NE 3NE 3
NE 4NE 4
NE 5NE 5
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Connection ProvisioningConnection Provisioning
• Goals– Offload the EMS by distributing control
– Also adds scalability, survivability and potential for more services
– Interoperability
• General Solution: Use a signaling protocol!– Signaling has been used in the telephone network for 60
years or more (signaling is rather new in data networks though…)
– Need to be careful with “behavioral” aspects…• e.g., call clearing is not an acceptable default behavior in the transport domain!
– Other benefit: a robust, bandwidth efficient restoration mechanism…
– There are a number of different signaling protocols being extended
Inter-Domain Networking (NNI)
Inter-Domain Networking (NNI)
The “Inter-domain” model is an inherent part of the current ITU-T standards for the control of
optical networks
The “Inter-domain” model is an inherent part of the current ITU-T standards for the control of
optical networks
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Domain ModelDomain Model
– Networks are organized as multiple domains:
• Administrative purposes
• Scaling purposes
• Security and Isolation
• Technology / Vendor differences…
– Examples
• Internet Autonomous Systems (AS)
• ITU-T G.805/ASON Domain Model
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Deployment IssuesDeployment Issues
Domain Model Domain Model
• Within Domain: homogeneous systems and protocols
• Different Domains: heterogeneous systems and protocols
UNIUNI UNIUNI
UNIUNI
Carrier ADomain X Domain Y
Domain Z
Carrier B
Generic Interdomain Protocol
Generic Interdomain Protocol
Feature-Rich Intra-domain Protocol
Feature-Rich Intra-domain Protocol Generic Inter-
domain Protocol
Generic Inter-domain Protocol
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Control Domain ConceptsControl Domain Concepts
• Separation of Control Mechanisms
– Protocols used between domains independent of what protocols used within domain
– Internal operation of domain “invisible” outside the domain
– Independence of internal protection or restoration mechanisms
• Carrier Uses for Domains
– Inter-vendor interoperability
– Gatekeeper mechanism for suppressing signaling or routing storms between domains
– Technology differences (all-optical, SDH,…)
– Service differences (restoration, etc…)
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OIF / ITU-T NNI between Control DomainsOIF / ITU-T NNI between Control Domains
• Goals– Enable interoperability by utilizing discovery, signaling and routing protocols
between control domains
A
Control Domain 1
ZControl Domain 3
Control Domain 4
Control Domain 5
Control Domain 2
protocol between domains
protocol between domains
protocol between domains
protocol between domains
protocol between domains
protocol between domains