Approach & perspectives for next generation DWDM networkPlanning & engineering Beyond 100G . Network planning with flexi colorless, directionless ,contetionless & griddles DWDM for succesful long haul network on 40G/100G

1. MNOP ( Multi Nodal Operation Protection )
Approach & perspectives for next generation
telecom transport network
Planning & engineering Beyond 100G and flexi colorless,
directionless ,contetionless & griddles DWDM
By Debasish Choudhury, VP- United Telecoms
Limited, July/2011
Mail : dchoudhury@utlindia.com ,
debasishchoudhury.sai@gmail.com

2. Target goals and objectives
• Bringing a TB ready transport infrastructure in DWDM:
– The network and system limitations arising from fiber etc need to be reduced
by hybrid modulations.
– The link budget and scaling the channel capacity to 100G plus with the
parameters of 10G system.
• Achieving GMPLS powered protection & restorations without Cross Connects (XC)
by O-O Systems :
– A colourless feature at Channel/transponders
– Bundling channels and creating virtual paths for directionless systems.
– Near Zero contentionless architecture
• Building a truly multivendor direction & contention less system for Metro, Data
centers & Long haul
– Building aspects of Wavelength routing in DWDM nodes. (MNOP)
– Sub lambda level of ODU0 based traffic grooming L2 feature with a channel
capacity of 100g or more

3. Multi nodal Operation Protection (MNOP)
-- The proposed methodology--
• Building blocks with MNOP ( Multi Nodal Operation Protection ) scheme:
– MNOP is a pattern built in leveraging GMPLS & other traffic engineering with enhanced MUX /DEMUX
systems. This enhances the ROADM and existing nodes similar in line to IPoWDM based wavelength
routing. The main aspects are :
A. Aggregation of wavelengths at a defined node and creating Virtual Lambda paths.
B. Enabling a tunable DEMUX layer with directionless MUX.
C. Enriching Alen wavelength on g.709 pattern to build 100g plus lambda on same
systems.
• Focus points:
– Flexible system to support 10G to 100g plus channel capacity.
– Creating a complete flexible lambda pattern with wavelength routing on low overheads.
– Adding new Optical compensatory systems for enhancing optical layers.
• System advantages
– The network behaves with a linear L2 & L3 powered structure.
– Easy to evolve direct services to emerging data centre needs ( like Warehouse scale
computing, clouds etc)
– Multi vendor and heterogeneous channel capacity assignments for Metro and long haul
networks.

4. For Multi vendor scenarios
IMPORTANT NOTE
The system had considered the GMPLS protocol based backplane schematics and latest
ITU-T recommendations on CDC.
Some references for understanding consideration are
• GMPLS Architecture :
– Quagga Routing Suite
– DRAGON GMPLS Architecture
• Research Initiatives:
– Lambda User Controlled Infrastructure for European Research architecture for Consolidated Grid-GMPLS
Control Plane prototype by POZNAN SUPERCOMUPTING & NETWORKING CENTRE (EU)
• Product , network planning & standards:
– Verizon
– IETF
– JDSU

5. MNOP ( Multi Nodal Operation Protection )
• What are the achievements by MNOP ( Multi Nodal Operation Protection ) scheme:
– This is a dynamic enhancement to GMPLS and OTN features which protects the lambdas in multiple
routes with pre assigned virtual paths.
– This also bundles multiple traffic in an effective way and enables wavelength routing at
DWDM equipments similar to that an MPLS router.

6. MNOP ( Multi Nodal Operation Protection )
- Nodes with traffic intelligence
• What are the achievements by MNOP ( Multi Nodal Operation Protection ) scheme:
– The leader node is assigned to have a task of picking all the snaps of traffic lambda it passes through it
and verifies with assigned link budgets to normal working conditions. It holds multiple virtual traffic
matrix and inserts this when there is a link disruption.
– The leader node have/can have a different modulated higher channel card.
– The leader nodes always keep a virtual backup path.

7. MNOP ( Multi Nodal Operation Protection )
• How MNOP ( Multi Nodal Operation Protection )
scheme works:
– This is a virtual topology built with a virtual link design
built amongst the selected nodes.
– The virtual path is bidirectional and have a backup traffic
matrix in sync with GMPLS layer.
– The traffics through this node are summed up and
assigned the dynamic backup routes keeping the traffic in
directionless pattern.
– When a disruption in link arises the pass through pattern
of node extends a colorless pattern to reroute the
wavelength with alerting the traffic pattern.

8. MNOP ( Multi Nodal Operation Protection )
Wavelength routing
• How MNOP ( Multi Nodal Operation Protection ) wavelength routing works:
– Colourless wavelength add/drop with directional routing
– Choose the bandwidth of the light path to match the service bitrate
– Use multiple copies of the same colour wavelength on the add/drop structure

9. MNOP ( Multi Nodal Operation Protection )
Wavelength routing-- continued
• advantages:
– Enables improved applications
– Network Defragmentation
– Bandwidth Adjustments
– Network Maintenance
– Network Restoration

10. MNOP ( Multi Nodal Operation Protection )
High capacity on local rings-IPoWDM
• Inserting CO-OFDM based alien wavelengths (Future ) or higher channel
capacities :
– Ease of same control plane mapped virtualisation opens up the door inside upper
capacity transponders in same modulation or different modulation to be inserted.
– The higher capacity channels with alien wavelengths will also support IP on
wavelengths.

11. MNOP ( Multi Nodal Operation
Protection )
what it solves ??

12. Why Rapidly-Dynamic ROADM Networks Not
Feasible?
A long-haul (L > ~800 km) transport system contains:
Many optical amplifiers:
• Most with adjustments needed for multiple pump laser powers
• Some with adjustable gain flattening filters (GFF)
• All with control circuits for optical transient control
Multiple ROADMs:
• Usually with per-channel variable optical attenuator adjustments
Multiple transponders
• Each with tuneable laser
• Many with tuneable dispersion compensators (TDC)
• Each with variable optical attenuator (VOA)
• Together, there DOZENS of things which need to be adjusted (“tuned”)
and collection of control loops makes some of them get VERY slow
[frequently minutes to converge]

13. Dynamic ROADM Networks : Photonic way

14. Legacy DWDM
Longer provisioning cycle than desired
– Many manual steps
– Across the country (both ends + maybe middle)
– Mux/demux inflexible
Static mapping: circuit - - wavelength
Transponders cannot be
pre-deployed without
Committing wavelengths.

15. Evolving DWDM- wish list
•Colourless: Able to send any wavelength to any port, and to change these assignments
automatically.
•Directionless: Allowing output ports to send traffic in any direction.
•Contention less: Allowing one ROADM port to use a wavelength that got dropped by
another port. This could be accomplished with an NxN switching element. Large all-optical
switches, of sizes up to 768x768, could also play a role here.
•Griddles: Some carriers think they'll want ROADM to assign wavelengths off of the
International Telecommunication Union (ITU) grid. When Terabit Ethernet gets invented,
for example, it might be easiest to let it occupy two ITU grid spaces, or 1.5, or some other
arbitrary proportion.

16. Evolving DWDM
Colourless add/drops
– Currently: transponders are tuneable but demux is not.
– Tuneable demux will enable transponders to be pre-deployed, and circuits to be
turned up rapidly. Transponder at B can be connected to A or C simply by tuning pair
of transponders to the same wavelength, and setting demux and ROADMs properly.
- Wavelength does not need to be chosen in advance.

17. Evolving DWDM : alternate approach-1
Building a metro/Data centre network
– This will require 100G (OTU4) ‘gray’ (non-WDM) optics on routers
– Preferably it will have NO colored optics in routers
– There will be multiple vendors for routers and for transport
– While IP routers are a big source of traffic, they are not the only one . There will
have other network layers and private line traffic which use long-haul transport –
not through core routers.
The approach will lead to :
• Interfaces to have ‘colored’ (long-haul wavelength) interfaces directly on IP
routers
•Or integrate long-haul optics in IP routers
• This is also “alien wavelength” architecture
This demands :
• A robust dynamic wavelength layer
• Converged cross-layer control and timing
• Functionalities with control and management software.

18. alternate approach-1 : Target Features and Objectives
• Terabyte capacity Optical metro area network
– Reduce OEO in the core, allow alien Waves by enhancing IPoWDM
• Extended GMPLS protocols for dynamic
provisioning
– Addition of CSPF Path Computation algorithms for wavelength routing
• Inter-domain service routing techniques
– Network Aware Resource Broker (NARB) for service advertising
• Application Specific Topology Description Language
– Formalized means to describe the application topology and network service
requirements
• Integration with real applications:
– Storage and other enterprise specific interfaces
– Various application level interfaces in service providers network

19. alternate approach-1 : target Features and Objectives
Photonic Architecture
• Principles:
– Standard practice of OEO engineering at every node is unnecessary in
metro/regional networks
• Allow the user/client to define the transport
– Core switching nodes should be all-optical:
• Any wavelength on any port to any other port
• Framing agnostic
– OEO is provisioned only as a service function at core nodes:
• To provide wavelength translation to avoid wavelength blocking conditions
• To provide regeneration iff network diameter and service specs require it, and only
on a request specific basis.
– OEO transponders are used at edge only for ITU translation
• External ITU wavelength signaling and sourcing is encouraged
– All waves are dynamically allocated using GMPLS protocols
• Extensions for CSPF path computation and inter-domain are new

20. alternate approach-1 : suggestive Features and Objectives
Generic Architectural Cells
Core Wavelength Switching Primitive Cell Edge Service Introduction and
-All waves are C-Band ITU compliant on 50/100 Ghz ITU spacing
-Any wave can be individually switched from any input port to any
Validation Cell
output port -Client interfaces provide wavelength
-Each port goes to either a) another core switching cell, or b) an edge conversion to ITU grid lambdas
cell -External wavelength interfaces verify
-Other wavelengths outside the C-Band are extinguished on entry and conformance of customer provisioned waves
are not progressed thru the switch. to network constraints
-The switching cell can block any/all input waves on any input port -Can also be used at core nodes to provide
-The switch is not sensitive to the content, framing of any data plane wavelength translation
wave.

21. where we are now
• The major scenarios at service providers are:
– Reconfigurable OADMs
– Alien wavelength conditioning ( minimum)
– Tunable wavelength transponders
– 40 gigabit wavelengths (?)
– Possibly other digital encoding formats such as RZ,
DPSK, etc.
• The development and deployment plans other
modulations and 100G on NLD networks are
less.

22. how ideally we should be
Dissecting GMPLS Transport : The missing blocks
IP/ {Ethernet, sonet, wavelength }
Core services No standardized Inter-Domain Routing
Architecture, including transport layer
GMPLS-{OSPF, ISIS}-TE
capability set advertisements
intra-domain routing
GMPLS-RSVP-TE signaling
No end-to-end
IP/Ethernet instantiation
campus LAN No Simple API Integration across
Non-GMPLS enabled
networks

23. MNOP takes where ?

24. MNOP Building block :
Virtual Label Switched Router: VLSR
• Many networks consist of switching components that do not speak
GMPLS, e.g. current ethernet switches, fiber switches, etc
• Contiguous sets of such components can be abstracted into a Virtual Label
Switched Router
• The VLSR implements GMPLS-OSPF-TE and GMPLS-RSVP-TE .
– Zebra OSPF extended to GMPLS
– KOM-RSVP likewise
• The VLSR translates GMPLS protocol events into generic pseudo-commands for the
covered switches.
– The pseudo commands are tailored to each specific vendor/architecture using
SNMP, TL1, CLI, or a similar protocol.
• The VLSR can abstract and present a non-trivial internal topology as a “black box”
to an external peering entity.

25. Virtual Label Switched Router: VLSR
VLSR
VLSR
VLSR VLSR OSPF-TE / RSVP-TE
OSPF-TE / RSVP-TE
? ?
LSR LSR
SNMP
control
Ethernet network GMPLS network
VLSR Abstraction

26. MNOP Building block :
Network Aware Resource Broker (NARB) Functions – IntraDomain
• IGP Listener • Edge Signaling Enforcement • Authentication
• Path Computation • ASTDL Induced Topology Computations • Accounting
• Scheduling • Authorization (flexible policy based)
• Edge Signaling Authentication
NARB Edge
Signaling
Authorization
Scheduling IP Control Plane
Authentication
Authorization
Accounting
End End
System System
Data Plane AS#
LSP
Ingress Egress
LSR LSR
Data Plane

27. Network Aware Resource Broker (NARB) Functions – Inter Domain
• InterDomain NARB must do all IntraDomain functions plus:
– EGP Listener
– Exchange of InterDomain transport layer capability sets
– InterDomain path calculation
– InterDomain AAA policy/capability/data exchange and execution
Transport Layer Capability Set Exchange
NARB NARB
NARB
End End
System System
AS 1 AS 3
AS 2

28. MNOP moves the NW to
“ Route & select” from “broadcast & select “

29. MNOP moves the NW to
“ Route & select” from “broadcast & select “
+
Effective CDC for M*N ROADM

30. MNOP moves the NW to
“ Route & select” from “broadcast & select “
+
Effective flexible Grid spectrum

31. Reference and Citations-1
• D. Basak, D. Awduche, J. Drake, and Y. Rekhter.
Multi-Protocol Lambda Switching: Issues in Combining MPLS Traffic Engineering
Control with Optical Corssconnects. Internet Draft, January, 2000.
• S. Chaudhuri, G. Hjalmtysson, and J. Yates. Control of Lightpaths in an Optical
Network. Internet Draft, February, 2000.
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1998.
• Coherent Optical OFDM Transmission Up to 1 Tb/s per Channel, Yan Tang Shieh,
W. Dept. of Electr. & Electron. Eng., Univ. of Melbourne,
http://ieeexplore.ieee.org/Xplore/login.jsp?url=http%3A%2F%2Fieeexplore.ieee.o
rg%2Fiel5%2F50%2F5170198%2F05071214.pdf%3Farnumber%3D5071214&authD
ecision=-203
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Concatenation in Transparent Mult iwavelength Optical Networks,” Journal of
Lightwave Technology, Vol. 20, No. 6, pp. 921-936, June 2002.

32. Reference and Citations-2
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power considerations in Optical Networks. IEEE Globecom '99 Symposium on High-Speed
Networks, December, 1999.
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Architectures for IP Optical Networking. Bell Labs Technical Jounal, January, 1999.
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1999.
• Awduche, J. Malcolm, J. Agogbua, and J. M. M. O'Dell. Requirements for Traffic Engineering
over MPLS. Request for Comments No. 2702, September, 1999.

33. Reference and Citations-3
• IETF. The MPLS Operations Mailing List. IETF's MPLS Working Group.
• K. Kompella, Y. Rekhter, D. Awduche, J. L. G. Hjalmtysson, S. Okamoto, D. Basak, G. Bernstein,
J. Drake, N. Margalit, and E. Stern.
Extensions to IS-IS/OSPF and RSVP in support of MPL(ambda)S.
Internet Draft, October, 1999.
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Approaches for Wavelength-Routed Optical WDM Network.
Optical Networks Magazine, August, 1999.
• ECOC 2009 - Symposium 6.7 : Dynamic Multi-Layer Mesh A Provider’s Perspective, by Peter
Magill, Executive Director, Optical Systems Research, AT&T Labs
• Dynamic Resource Allocation over GMPLS Optical Networks , The DRAGON Project
http://www.dragon.maxgigapop.net

34. Reference and Citations-4
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