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© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 1
GMPLS Lambda aware
Dirk Schroetter, Consulting Systems Engineer
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 2
Agenda
Defining the goal based on the trends
Intrumenting the DWDM Layer
State of the Art
Cisco Approach
Summary
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 3
Defining the goal based on the trends
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 4
Overall Traffic Growth Impact Market trends:
Dramatic IP increases in Metro traffic due to Video + Ethernet business services
Customers demand rapid transport service turn-up
Providers are leveraging Ethernet to provision a variety of services
Video key driver
Drives requirements:
Service Transparency
Topology Flexibility
Simplified, Cost Effective Operation
Global IP Traffic—By Segment
For Perspective:
1 Exabyte = 5 X All the World‟s Printed Matter
5 Exabytes = All Words Ever Spoken
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 5
2006
Core Metro Access
Core Metro Access3.8 EB/mo 4.2 EB/mo 4.2 EB/mo
19.2 EB/mo 28.5 EB/mo 29.5 EB/mo
Core Grows Fivefold, Metro Sevenfold
Source: Cisco, 2008
2011
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 6
What should an optical control plane do?
L1L2
L3
L4
L5
L6
L7
L8
L9
L10L11
L12
L13 L14
L15
L16 L17 & L18 (l)
WLC
R1
R2
R3
N2
N1
N3
N4
N5
N6 N8
N7
Router
Fixed OADM
Multidegree ROADM
Multidegree ROADM(omnidirectional)
Elements of an OCPResource Discovery
• Network Elements
• Links
• Link Properties
• Optical Transmission Parameters
Topology Discovery
• Nodes
• Links
• Hypothetical Connectivity Matrix
Traffic Provisioning
• Centralized vs.rdistributed
• Pre-computed vs. On-the-fly
• Regeneration support
• Intelligent interworking with client layer
Traffic Restoration
• In cooperation with client layer(s)
• Pre-computed vs. On-the-fly
Network Restoration
• Use of Regens, Multi-Degree nodes
Network Optimization
• Computationally hard
Increasing Complexity
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 7
Manual Patching Manual provisioning of each node
Manual patching of each node
High OpEx
Truck rolls to every node
With ROADMs and WXC Manual provisioning via NMS
Autopatching via intermediate ROADMs and WXC
Lower OpEx
More service flexibility
Truck rolls to end points
Dynamic Service Activation with Colorless, Omnidirectionality and S-GMPLS Auto provisioning wavelength on demand
via S-GMPLS
Auto patching via ROADMs and WXC
Lower OpEx even further
No truck rolls
Towards Dynamic Service Activation
1
432
6
5
Manual Provisioning Manual Patching
6
8
75
Manual PatchingManual Provisioning
1
432
DynamicService
Activation
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 8
Cisco‘s view on OCPs
If IP is driving the demand in the transport network, IP models should take precedence
Statistical muxing, Traffic Management, QoS
For the forseeable future, IP will be dominating the traffic growth, but other client layers continue to exist
Multiple client layers need to be supported
DWDM needs to be intelligent
One size does not fit all
Topology awareness is beneficial for some client layers, others don„t need it
Long-term connections vs. Short-lived ones
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 9
Instrumenting the DWDM Layer
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 10
Instrumenting DWDM for OCPs
Instrumenting the DWDM layer
Tunability
• Optical channels can be moved and changed to different wavelengths completely via software
Colorless
• Ability to change the wavelength aspects of these devices without moving any physical fibers
Omni-Directional
• A fixed fiber port interface directed to any of the degrees within the ROADM node
Impairment-aware
• DWDM system must be able to measure optical impairments
✔ ✔Release 9.2
✔Update in
R 9.2
Open, requires
work in ITU
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 11
Use of Omni-Directionality
Oakland
Fremont
Pleasanton
San Francisco
Burlingame
Hayward
Santa Rosa
Fairfield
A
B
CD
AB
C
D
Reaction to a Fiber Cut no longer requires a Site visit
Omni-directional switching extend network flexibility
– Channels can be re-routed to respond to network failures, congestions or maintenance
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 12
Oakland
Fremont
Pleasanton
San Francisco
Burlingame
Hayward
Santa Rosa
Fairfield
A
B
CD
AB
C
D
Colorless allows to use different wavelengths for the different sections of the optical path to avoid congestion situations
R
Use of Colorless
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 13
Applying Colourless with Tuneable Optics
One interesting feature, enabled by colourless ROADMs, is equipment protection
1:N protection can be used to protect N interfaces with 1 spare interface, provided that the system supports the following features:
Tuneable TXTs
Colourless ROADMs
Protection Mechanism:
1. All the line-cards are working properly
2. A failure happens on red wavelength
3. The system tunes (on both sides) the spare channel on the proper wavelength
4. When the original interface has been repaired the systems reverts to normal operation
5. And it is ready to protect a new wavelength…
6. …green one this time
DWDM(MSTP)
Client Equip.(CRS-1)
Line Cards
Possibility for large savings
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 14
Approaches to OCP design
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 15
Hide Network Details from Other Departments
and Customers
IP Control Plane w/Intelligence and
Lowest OpEx
AugmentedModel hybrid of peer and
overlay
Optical Control Plane Models
Overlay Model
(OIF/ASON)
Augmented
S-GMPLS Model
Peer/Integrated GMPLS Model
(IETF)
Optical Control Domain
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 16
OIF/ITU ASON Overlay Implementation
Routers peers with each other
Transport network is not visible from routers
Transport setup request can be initiated by routers
End-to-end LSP Set up
Call connection module like PNNI ATM ILMI
Layer 1 view
UNI-CEMS
I-NNII-NNI
IP/MPLSIP/MPLS
UNI (OIF)UNI (OIF)
UNI-C
UNI-N
E-NNI UNI-N
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 17
IETF GMPLS Peer Implementation IETF
Routers and transport NEs are peers
GMPLS between router and optical NE
GMPLS between optical NEs
End-to-end LSP set up
Layer 3 view on the world
EMS
GMPLS NetworkGMPLS
DWDMDWDM
GMPLSIP/MPLS
IP/MPLS
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 18
IETF Segmented-GMPLS Peer Model
The S-GMPLS model is a hybrid model between the full-peer and overlay models
Border router received routing information from the optical devices as well as routers
The Border router keeps the optical and router domain topology information in segmented routing tables
No routing information from the router region is carried into the optical region
Logical separation on the border router
Border Router
GMPLS Network
GMPLSGMPLS
GMPLSGMPLS
GMPLS
Router Topology
Optical Topology
IP/MPLS
IP/MPLS
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 19
IETF Segmented-GMPLS PCE Model
IETF PCE area boarder router module
Path Computation Element (PCE)
Lives on a server
Request PCE
Explicit path or pump the path (ingress and egress)
GMPLS Network
GMPLS GMPLS
GMPLSGMPLS
GMPLS
IETF PCEIETF PCE
IP/MPLS
IP/MPLS
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 20
Does the IP layer need optical topology?
Not all of the nodes
Border routers
PCEs
But as has been shown in all other cases:
Topology hiding can lead to suboptimal routing decisions
Topology hiding requires a much more intelligent UNI (SRLG)
Some form of topology required to support EROs (Explicit Route Objects)
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 21
Topology awareness helps in this case
1. Request connection from A to C by optical user (via EMS) orIP user (via CLI), specifying:
Ports at both ends (optional)
Route diversely from a set of links (subnets)
Route the same way as another link (part of link bundle add/remove?)
2. The network will find ports at A & C as well as an optical path that respects these SRLG constraints
3. The network will then set up that path end to end
(b) Good Mapping
A
B
C A
B
CX
L3 Topology L0 Topology (a) Bad Mapping
Y
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 22
State-of-the-art
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 23
A quick review of MPLS
Routers or switches that handle MPLS and IP are known as Label Switch Routers (LSRs)
LSRs at the edge of MPLS networks are sometimes referred to as Label Edge Routers (LERs)
Ingress LERs are responsible for classifying unlabelled IP packets and appending the appropriate label.
Egress LERs are responsible for removing the label and forwarding the unlabelled IP packet towards its destination.
Barcelona
Delmenhorst
LSR
LSRLSR
LSP
LSR
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 24
Enter GMPLS: Nested LSPs, more NEs
Unified Control PlaneGMPLS
IP Routing ProtocolsWith Extensions
OSPF, ISIS
Label Distribution ProtocolsCR LDP, RSVP TE
MPLS TERSVP TE
Forwarding Plane
PSCDomain
GMPLS Domain
TSCDomain
OTN
LSCDomain
FiberDomain
TELSP
TELSPSONET
SDH NE
SONETSDH NE
OXC
OXC OXC
OXC
Router
Router
Router
Router
SONETSDH NE
SONETSDH NE
RouterRouter
RouterRouter Switch
Switch
Switch
Switch
An LSP must start and end on the LSRs of the same type.
Nested LSPs
FA-LSC LSPFiber
FA-TDM LSPLambda
FA-PCS LSPTDM
LSP Packet
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 25
GMPLS Overview
GMPLS supports five types of interfaces:
PSC - Packet Switching Capable: IP/MPLS
L2SC - Layer-2 Switching Capable: ATM, FR, Ethernet
TDM - Time-Division Multiplexing: SONET, SDH, G.709 ODUk
LSC - Wavelength Switching: Lambda, G.709 OCh
FSC - Fiber Switching
GMPLS extends MPLS/MPLS-TE control plane
LSP establishment spanning PSC or L2SC interfaces defined in MPLS/MPLS-TE control planes
Extensions primarily driven by characteristics of TDM/LSC/FSC
GMPLS extends these control planes to support ANY class of interfaces (i.e. layers)
ASON may and WSON does use GMPLS
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 26
ASON Control Plane vs. Transport Plane
ASON only deals with the signaling & abstracted transport elements between subnetworks and at the UNI/NNI border
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 27
ASON Protection
1. Working & Protect path are set up2. Link failure -> NEs signal to CP3. CP signals ingress & egress NE
Classical TDM 1+1 protection
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 28
ASON Restoration
1. Working path is set up2. Link failure -> NEs signal to CP & working path is released3. CP calculates new path, possibly using crankback4. CP signals new working path to subnetworks
Classical Rerouting & Restoration
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 29
WSON Operation
Establish lighpath through PATH message
Explicit routes supported
WSON supports wavelength converters (e.g. Regens)
L1L2
L3
L4
L5
L6
L7
L8
L9
L10L11
L12
L13 L14
L15
L16 L17 & L18 (l)
WLC
R1
R2
R3
N2
N1
N3
N4
N5
N6 N8
N7 Router
Fixed OADM
Multidegree ROADM
Multidegree ROADM(omnidirectional)
Path (R3)Path (N1,N2,N4,N6,N8,R3)Path (WLC,R3)
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 30
Comparing Control Planes
ASON GMPLS WSON MPLS
Networks
Client SDH/PDH (OTN?)IP, SDH, PDH, Ethernet, OTN,
DWDM
Same as GMPLS
IP
Server SDH/PDH (OTN?)SDH, PDH,
Ethernet, OTN, DWDM
(SDH, PDH, Ethernet) OTN,
DWDMNone
Protection 1+1 1+1, 1:1, 1:n 1+1, 1:1, 1:n 1+1, 1:1, 1:n
Restoration Yes, Crankback Yes Yes Yes
SummaryMainly SDH/PDH focus, “Next-Gen”
SDH
Introduces concept of
„Server Layer Network“ to
MPLS
Mainly DWDM focus, still
architecture battle
Basis for MPLS-TP, extended through GMPLS
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 32
Cisco GMPLS lambda aware
Control Control
IPoDWDM Open Network (e.g. SDH)
ControlGMPLS
aware
Control
UNI for OCh CC
UNI for OCh NC
UNI for OCh NC
Control
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 33
Cisco GMPLS Lambda aware
Control plane will provide:
UNI for IP and other client layers
Toplogy Information (to support EROs)
Coordinated OAMP between the layers
GMPLS Lambda aware Control Plane
IP Client Layer Other Client Layers
UNI Topology Info OAMP
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 34
GMPLS DWDM aware Initial Phase
LSP Provisioning
DWDM Aware algorithm (linear / non linear impairment)
GMPLS extension (OSPF-TE, RSVP-TE)
OSPF
UNI
UNI
UNI
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 35
GMPLS DWDM aware second phase
Optical Restoration
Network Optimization
Optical Auto-bandwidth
Protection Protocol
Protection Protocol
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 36
Optical Auto-Bandwidth Vary channel count as
trunk load changes
Router measures utilization for L2 link bundles (LAG)
If utilization is high – request the set up of another wavelength from L0 and add it to the link bundle
Original topology retained to avoid convergence issues – channel add/remove within existing link bundles
© 2008 Cisco Systems, Inc. All rights reserved. Cisco ConfidentialPresentation_ID 38
Summary
To fulfill its promise, an OCP must reside on an intelligent optical layer
Tunability, Colorless and Omnidirectionality are a must
If IP is king, an augmented peer model makes sense
Support for EROs, MPLS FRR support, Rearchitect Protection in the core
Standards are evolving and not yet finalized
... Good opportunity for you to make your voice heard in IETF
... ASON and OTN switching model of very limited use when you deal with IP
Cisco takes a balanced and phased approach
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