Transcript GMPLS Control Plane Software Architecture

GMPLS-Based Control Plane for
Optical Networks
June-Hyun, Moon
Computer Communications LAB.,
Kawangwoon University
[email protected]
Introduction to Generalized MPLS
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IP/MPLS-based distributed control plane
 Automatic service provisioning
 Dynamic network topology and resource availability
dissemination
 Neighbor dsicovery and link management
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Applicable to multiple network technologies with
different capabilities
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Packet-switch capable interfaces (e.g. routers)
TDM capable interface (e.g. SONET/SDH)
Lambda-switch capable interface (e.g. optical cross-connects)
Fiber-switch capable interface (e.g. photonic switches)
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GMPLS Motivation
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Interoperability
 Across multi-vendor transport network as well as their clients
 Provides integrated control plane for multiple types of
equipment
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High scalability for large, dynamic network with many
connections/LSPs
Simplifies end-to-end provisioning
Facilitates unified traffic engineering
 Peer-to-peer
 Overlay
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Allows de-coupling control and data channels
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Standardization Activities
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IETF
 Extends MPLS/IP protocols based on generalized interface
requirements
 Signaling (RSVP-TE and CR-LDP with GMPLS extensions)
 Routing (OSPF-TE and IS-IS with GMPLS extensions)
 Neighbor discovery and link managements (LMP)
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OIF
 Focuses on application of IETF protocols in an overlay model
 Generates implementation agreements
 UNI 1.0 (approved in October 2001)
 NNI (in progress)
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ITU
 Automatic Switched Optical Network (ASON)
 UNI and NNI interfaces
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Optical Network Architecture
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GMPLS Control Plane Software Architecture
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GMPLS Application – GMPLS manager
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Coodinates the functions of all GMPLS control plane
modules
Communicates with EMS/NMS or external
management systems
Creates and deletes signaling and routing interfaces
Performs admission control
Executes connection setup and teardown requests
Provides the interface between the control plane and
the actual data plane
 Set up and teardown cross connects
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GMPLS Manager
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State Machine
 Manages LSP operation
 Facilitates multitasking and error handing
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Database
 Maintains allocated and ready-to-use resource information
 Tracks the state of existing connections
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Two Sub-modules
 GMPLS controller
 Performs control functions
 GMPLS adapter
 Provides an interface to the routing and signaling components
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GMPLS Control Plane Software Architecture
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Routing
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Disseminates network topology and resource availability
Manages the link state database and routing tables
Provides the routing information to the routing component users
 Access the routing information
 Make routing decision
 Obtain explicit route
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OSPF GMPLS extensions
 Support traffic engineering over different types of links
 Link bundling
 Aggregates and abstracts the attributes of the links with similar
characteristics between a pair of nodes
 Advertised as a single link bundle or TE link
 Reduces the amount of information handled by routing component
 Improves routing scalability
 Aggregation leads to information loss
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Path Computation
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Explicit route for the requested LSP computed at the
ingress node
Takes into account a set of constraints
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Resource availability
Bandwidth requirements
Protection/restoration (e.g. 1+1, shared mesh)
Traffic engineering constraints
Not subject to standardization
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GMPLS Control Plane Software Architecture
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Signaling
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Extablishes and deletes signaling sessions with
neigbor signaling peers
Processes LSP-related requests the GMPLS manager
 Generates appropriate control messages
 Sends them along the path
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Receives and decodes incoming messages
 Passes the appropriate notifications to the GMPLS manager
for action
 Callback functions
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LSP setup
 Label request
 Resource reservation and allocation
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LSP deletion
 Label and resource release
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Signaling (cont.)
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RSVP-TE with GMPLS extensions
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Generalized label request and generalized label
Suggested label
Label set
Explicit label control
Bidirectional LSP
Notification on error
Protection information
Administrative status information
Control channel separation and fault handling
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GMPLS Control Plane Software Architecture
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Neighbor Discovery and Link Management
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Establishes and maintains control channel connectivity
between neighbors
 Configuration message
 Keep-alive
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Discovers and correlates the physical properties of
data links
 Test message
 Link summary message
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Verifies the data link connectivity
Localizes and handles link failure
 Link fault management
 Leads to local span or end-to-end recovery
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