Using Multi-Layer Routing to Provision Services across
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Transcript Using Multi-Layer Routing to Provision Services across
Using Multi-Layer Routing to
Provision Services across
MPLS/GMPLS Domain
Boundaries
Andrew G. Malis
Chief Technologist, Tellabs
Chairman and President, MFA Forum
1
Discussion of Convergence is
Everywhere
“…the access infrastructure telcos are building to support IPTV
services will finally give them the ability to converge voice,
video and data onto a single network…”
– Americas Network
Pseudo-Wires are “the solution for convergence in future
telecom networks, because it preserves profitable legacy
services even as it enables the creation of a truly nextgeneration network” – Heavy Reading
“3GPP defines a new subsystem to enable the convergence of
voice and data applications and the harmonization of various
mobile network technologies over IP”
– Deutsche Bank
2
Convergence is changing
the face of the network
The Benefits of Convergence
Services reduced to applications on converged infrastructure
Reduced operations
Reduced core cap-ex
New services can be provided
Individual Networks per Service limited service interaction
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The details in getting there are not small…
The Reality of Convergence
Non-native service delivery
End User Services are always layered on something else
Which Technology for Convergence?
WDM
Layer 1 (GMPLS)
Layer 2/3 (MPLS)
The whole network will not be converged overnight
Too many existing services already deployed
The whole network will never be completely converged
Fully depreciated equipment still generates revenue
4
How can this all be supported
operationally?
Access A
(WDM)
Islands of
Technology
CPE-A
Core
(MPLS Pseudo Wire)
CPE-B
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Access B
(SONET/SDH)
Access A
(WDM)
Different
Organizations
Manage These
Technologies
CPE-A
Core
(MPLS Pseudo Wire)
CPE-B
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Access B
(SONET/SDH)
We will fill
your order
within 3
months
Access A
(WDM)
Provisioning
Service is
expensive and
time consuming
CPE-A
Core
(MPLS Pseudo Wire)
CPE-B
I forgot that
we ordered
this service!
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Access B
(SONET/SDH)
Access A
(WDM)
OCN
UNI
WDM Network
GE/NNI
T1, T3, OCN
UNI
What would be
best?
GE/NNI
OCN
UNI
GE/NNI
GE/NNI
CPE-A
T1, T3, OCN
UNI
10/100
BPON
BPON
GE/NNI
BPON
GE/UNI
Core
(MPLS Pseudo Wire)
10/100
GE/MPLS
CPE-B
Access B
(SONET/SDH)
OCN/NNI
10/100
nxT1
T1, T3, OCN
UNI or Null
T1, T3, OCN
UNI or Null
OCN/NNI
OCN/NNI
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MPLS Network
OCN/NNI
nxT1
10/100
GE/UNI
OCN/NNI
STS1 Network*
OCN/NNI
Sure, we’re
setting your
service up
as we speak
OCN
UNI
WDM Network
GE/NNI
T1, T3, OCN
UNI
GE/NNI
OCN
UNI
GE/NNI
GE/NNI
T1, T3, OCN
UNI
10/100
BPON
BPON
GE/NNI
BPON
GE/UNI
10/100
End-to-end Signaled
Service Provisioning
GE/MPLS
10/100
GE/UNI
nxT1
MPLS Network
OCN/NNI
OCN/NNI
nxT1
10/100
T1, T3, OCN
UNI or Null
T1, T3, OCN
UNI or Null
Wow,
that was
fast!
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OCN/NNI
OCN/NNI
OCN/NNI
STS1 Network
OCN/NNI
How Can This Be Accomplished?
Common flexible control method that understands layering
Path Computation that understand layered networks
Provides service routing given view of potential/available server
layer resources
Signaling mechanisms that coordinate calls in different
layers
OSSes that can handle integrated views of layer networks
Relate services requests (client layer calls) to server resources
in use
Definitions for server layer resources other than SONET/SDH
An Added Benefit: Integrated operations
Operations convergence possible due to Common control
methods
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Why Use GMPLS?
Establishes a common control plane for different networking
technologies
Converge Packet, Cell, TDM, and Optical administrative controls
Automates connection management for all traffic types
Path setup and management (for Packet, Cell, TDM, and Optics)
Handles topology changes automatically
Self-discovery and dynamic configuration of network resources
Provides static and dynamic path reroutes and restoration
Supports Peer-to-Peer and Overlay network models
Integration of optical switches, optical transport, and label
switching routers
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Making Path Computation Layer
Aware
Routing today treats different technologies as separate
topology graphs
SONET Network
PON Access
MPLS-TE
Network
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WDM Network
Making Path Computation Layer
Aware
Normal Path Computation cannot find paths between
endpoints on different islands
SONET Network
PON Access
MPLS-TE
Network
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WDM Network
Making Path Computation Layer
Aware
As a result, end-to-end services are separately routed by
each island, and interconnected by hand
SONET Network
PON Access
MPLS-TE
Network
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WDM Network
Making Path Computation Layer
Aware
By merging the graphs, adding client-layer matrixes and
client/server adaptation, the graph becomes continuous
SONET Network
PON Access
MPLS-TE
Network
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WDM Network
Making Path Computation Layer
Aware
GMPLS routing extensions
Link Attribute Announcements that:
remove ambiguity of adaptations supported
announce adaptations in a technology independent manner
necessary to allow for source routing to be done anywhere
include link costs that take into account:
different costs for each layer supported by a link
cost to utilize adaptation
Path Computation Algorithm that:
understands multiple matrices per node
updates “signal stack” when adaptations are pushed/popped
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IP & Optical Layer Combination
Practical Example
PE
MPLS Layer
P
GMPLS Layer
OXC
Major Objectives:
-Eliminate electrical packet processing in core
-Minimal or no change to existing MPLS routers
-Take advantage of TE in both networks – carry out multi-level TE
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MPLSGMPLS Interworking:
Overlay vs. Peer to Peer
Overlay Model
Optical Domain is not visible to IP domain
MPLS domain can not perform efficient TE
Do not have to update MPLS nodes to
GMPLS
Peer to Peer Model
Optical Domain is visible to IP domain
Optimal route assured since the MPLS
network can perform efficient TE by
understanding GMPLS network resources
Must update MPLS node to GMPLS
Can we take advantage of both models?
18
Optimal Design of an MPLS Core Network
P routers
Service
Demands
PE routers
LSP mesh between PEs originally traverses P routers
Direct PE-PE tunnels preferable where sufficient
commonality of traffic endpoints exists
Move LSPs to direct route reducing P-router load
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Feasible and cost-effective with GMPLS
Essence of Multi-Layer Core Optimization
PE
LSPs
Original
Direct
MPLS
Layer
P
Transport
Layer
Original tunnel
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Six router interfaces
Direct tunnel
Forwarding on two P routers
Ten transport interfaces
Two router interfaces
Six transport interfaces
2x bandwidth on links to P routers
GMPLS affords dynamic, optimal size direct tunnels –
without necessity to wait for transport service orders
Standards Activities
GMPLS
IETF – Multi-region Network
draft-shiomoto-ccamp-gmpls-mrn-reqs-03.txt
draft-leroux-ccamp-gmpls-mrn-eval-02.txt
ASON
ITU – Multi-layer calls and Multi-layer Routing
G.8080 Amendment 2
Q12/15 March 2005 Interim WD53r1
OIF – UNI 2.0 Ethernet Services & E-NNI Routing
Multi-layer call support
Architecture supports multi-layer routing (oif2004.477)
Demonstrated at Supercomm 2005
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Conclusion
Convergence is occurring in the network
New Services
Lower CapEx and OpEx for network operators
MPLS has become the industry-standard mechanism for
data network convergence (Layer 3 and Layer 2 services)
GMPLS is being deployed as optical network equipment
replacement picks up
Flexible control methods that support layering are in
progress
Standardization activities underway in ITU, IETF and OIF
Multi-vendor interoperability already demonstrated
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