packets & photons: the emerging two layer network
DESCRIPTION
Packets & Photons: The Emerging Two Layer Network. October 2001. Agenda. History of IP Backbones The Emerging Two Layer Network Network Platforms Standards and Forums GMPLS. Core Router. Core Router. ATM Switch. ATM Switch. MUX. MUX. SONET/SDH ADM. SONET/SDH ADM. SONET/SDH - PowerPoint PPT PresentationTRANSCRIPT
1Copyright © 2000, Juniper Networks, Inc.
Packets & Photons: The Emerging Two
Layer Network
October 2001October 2001
2
Agenda
History of IP BackbonesHistory of IP Backbones
The Emerging Two Layer NetworkThe Emerging Two Layer Network
Network PlatformsNetwork Platforms
Standards and ForumsStandards and Forums
GMPLSGMPLS
3
Typical IP Backbone (Late 1990’s)
Data piggybacked over traditional voice/TDM transportData piggybacked over traditional voice/TDM transport
SONET/SDHDCS
SONET/SDHDCS
CoreRouter
ATMSwitch
MUX
SONET/SDHADM
CoreRouter
ATMSwitch
MUX
CoreRouter
ATMSwitch
MUX
CoreRouter
ATMSwitch
MUX
SONET/SDHADM
SONET/SDHADM
SONET/SDHADM
4
Why So Many Layers?
RouterRouter Packet switchingPacket switching Multiplexing and statistical Multiplexing and statistical
gaingain Any-to-any connectionsAny-to-any connections Restoration (several Restoration (several
seconds)seconds) ATM/Frame switchesATM/Frame switches
Hardware forwardingHardware forwarding Traffic engineeringTraffic engineering Restoration (sub-second)Restoration (sub-second)
MUXMUX Speed match router/ Speed match router/
switch interfaces to switch interfaces to transmission networktransmission network
SONET/SDHSONET/SDH Time division Time division
multiplexing (TDM)multiplexing (TDM) Fault isolationFault isolation Restoration Restoration
(50mSeconds)(50mSeconds) DWDMDWDM
Raw bandwidthRaw bandwidth Defer new constructionDefer new construction
ResultResult More vendor integrationMore vendor integration Multiple NM SystemsMultiple NM Systems Increased capital and operational costsIncreased capital and operational costs
5
SONET/SDH
DWDM
CoreRouter(IP/MPLS)
IP Backbone Evolution
MUX becomes MUX becomes redundantredundant
IP trunk requirements IP trunk requirements reach SDH aggregate reach SDH aggregate levelslevels
Next generation Next generation routers include high routers include high speed SONET/SDH speed SONET/SDH interfaces interfaces
CoreRouter(IP/MPLS)
MUX
SONET/SDH
DWDM(Maybe)
FR/ATM Switch
6
SONET/SDH
DWDM
CoreRouter(IP/MPLS)
IP Backbone Evolution
Removal of ATM Removal of ATM LayerLayer
Next generation Next generation routers provide trunk routers provide trunk speedsspeeds
Multi-protocol Label Multi-protocol Label Switching (MPLS) on Switching (MPLS) on routers provides routers provides traffic engineeringtraffic engineering
CoreRouter(IP/MPLS)
MUX
SONET/SDH
DWDM(Maybe)
FR/ATM Switch
7
Removing the ATM Layer
Why Remove ATM?Why Remove ATM? Two networks to manage - IP and ATMTwo networks to manage - IP and ATM Cell tax Cell tax Lack of high-speed SAR interfacesLack of high-speed SAR interfaces High density of virtual circuitsHigh density of virtual circuits IP routing protocol stressIP routing protocol stress
Logical Topology
8
Agenda
History of IP BackbonesHistory of IP Backbones
The Emerging Two Layer NetworkThe Emerging Two Layer Network
Network PlatformsNetwork Platforms
Standards and ForumsStandards and Forums
GMPLSGMPLS
9
Collapsing Into Two Layers
Optical Transport(OXCs, WDMs, SONET ?)
Optical Core
IP Service (Routers)
10
Collapsing Into Two Layers
IP router layer functionsIP router layer functions Service creationService creation Multiplexing and statistical gainMultiplexing and statistical gain Any-to-any connectionsAny-to-any connections Traffic engineeringTraffic engineering Restoration (10s ms)Restoration (10s ms) Subscriber to transport speed matchingSubscriber to transport speed matching Delay bandwidth buffering and congestion controlDelay bandwidth buffering and congestion control Internet scalabilityInternet scalability
Optical Transport(OXCs, WDMs, SONET ?)
Optical Core
IP Service (Routers)
11
Collapsing Into Two Layers
Optical transport layer functionsOptical transport layer functions TDM and standard framing formatTDM and standard framing format Fault isolation and sectioningFault isolation and sectioning Restoration (10’s ms)Restoration (10’s ms) SurvivabilitySurvivability Cost efficient transport of massive bandwidth (DWDM)Cost efficient transport of massive bandwidth (DWDM) Long haul transmission distancesLong haul transmission distances Metro transmission distances ????Metro transmission distances ????
Optical Transport(OXCs, WDMs, SONET ?)
Optical Core
IP Service (Routers)
12
The Emerging Two-Layer Network
Data Layer
Transport Layer
Routers
OXC’s
WDM’sLH Transport
TDM’s
IP Services
Reduced costReduced cost Transport layer visible to IP Transport layer visible to IP
ServicesServices Transport layer signaling is Transport layer signaling is
an open standard (RSVP & an open standard (RSVP & CR-LDP)CR-LDP)
Reduced complexityReduced complexity Network more scalableNetwork more scalable Uniform admin & Uniform admin &
management of IP and management of IP and transport layerstransport layers
13
Agenda
History of IP BackbonesHistory of IP Backbones
The Emerging Two Layer NetworkThe Emerging Two Layer Network
Network PlatformsNetwork Platforms
Standards and ForumsStandards and Forums
GMPLSGMPLS
14
SONET/SDH Benefits
Rapid and predictable restorationRapid and predictable restoration 10s of ms; depends on ring size10s of ms; depends on ring size Simple to engineerSimple to engineer
Standard framing and multiplexing Standard framing and multiplexing (Time Division Multiplexing [TDM])(Time Division Multiplexing [TDM])
MaintainabilityMaintainability Performance monitoringPerformance monitoring Fault isolation and sectioningFault isolation and sectioning Bandwidth managementBandwidth management Network managementNetwork management
TransparencyTransparency Voice, video or data trafficVoice, video or data traffic
ChallengeChallenge Remove complexity Remove complexity
and keep benefitsand keep benefits
15
TrafficQuickly
ReroutedAfter Failure
SONET/SDH Benefits
Rapid and predictable restorationRapid and predictable restoration 10s of ms; depends on ring size10s of ms; depends on ring size Simple to engineerSimple to engineer
Standard framing and multiplexing Standard framing and multiplexing (Time Division Multiplexing [TDM])(Time Division Multiplexing [TDM])
MaintainabilityMaintainability Performance monitoringPerformance monitoring Fault isolation and sectioningFault isolation and sectioning Bandwidth managementBandwidth management Network managementNetwork management
TransparencyTransparency Voice, video or data trafficVoice, video or data traffic
ChallengeChallenge Remove complexity Remove complexity
and keep benefitsand keep benefits
16
SONET/SDH Limitations
Traditional SONET/SDH-based networksTraditional SONET/SDH-based networks Engineered for voice, not dataEngineered for voice, not data Slow to provisionSlow to provision
Planning complexityPlanning complexity Grooming complexityGrooming complexity Delivery measured in weeksDelivery measured in weeks
Expensive to scaleExpensive to scale Space, power, one wavelength per chassisSpace, power, one wavelength per chassis
InflexibleInflexible Static not dynamic bandwidthStatic not dynamic bandwidth Granularity – why not 5.5Gbps ?Granularity – why not 5.5Gbps ?
Little interoperability at “control plane”Little interoperability at “control plane” Customers forced to buy from one vendorCustomers forced to buy from one vendor Stifles “best-in-class” deploymentStifles “best-in-class” deployment
Packet layer – no visibility into optical layerPacket layer – no visibility into optical layer
17
What is an IP Router?
Minimum qualificationsMinimum qualifications Capable of switching IP datagrams: Capable of switching IP datagrams:
L3 forwardingL3 forwarding Symmetric any-port-to-any-port Symmetric any-port-to-any-port
switching speedswitching speed Delay-bandwidth buffering, Delay-bandwidth buffering,
plus congestion controlplus congestion control Internet scale IS-IS, OSPF, MPLS, BGP4Internet scale IS-IS, OSPF, MPLS, BGP4
Today’s benchmarkToday’s benchmark Wire-rate forwarding on all ports Wire-rate forwarding on all ports
for 40-byte packetsfor 40-byte packets Performance independent of loadPerformance independent of load Support of CoS queuing, shaping, Support of CoS queuing, shaping,
and policingand policing Traffic engineeringTraffic engineering Classification and filtering at wire rateClassification and filtering at wire rate
A Device Which Moves IP Datagrams Across
an Internetwork From Source to Destination
1 - Physical
2 - Datalink
4 - Transport
5 - Session
6 - Presentation
7 - Application
ISO 7 Layer Model
3 - Network3 - Network
18
What is an IP Router?
Optimal routesOptimal routes Calculate and select the best routes – Calculate and select the best routes –
many methodsmany methods SimplicitySimplicity
Functional efficiency with low routing Functional efficiency with low routing protocol overheadprotocol overhead
Robust and stableRobust and stable Predictable and correct functionality Predictable and correct functionality
in a variable environment (hardware in a variable environment (hardware failure, high load, topology changes)failure, high load, topology changes)
Rapid convergenceRapid convergence Slow route calculations cause loops Slow route calculations cause loops
and drops in serviceand drops in service FlexibilityFlexibility
Speed + accuracy to adapt to Speed + accuracy to adapt to network changes (bandwidth, delays, network changes (bandwidth, delays, queues, traffic levels, etc.)queues, traffic levels, etc.)
Routing Algorithm Goals
1 - Physical
2 - Datalink
4 - Transport
5 - Session
6 - Presentation
7 - Application
ISO 7 Layer Model
3 - Network3 - Network
19
What is an IP Router?
Any-to-any connectivityAny-to-any connectivity Internet scale routing allows anyone Internet scale routing allows anyone
to connect to anyone to connect to anyone (within or outside of own company)(within or outside of own company)
ApplicationsApplications Processing granularity to Processing granularity to
differentiate HTML from FTPdifferentiate HTML from FTP MulticastMulticast
Not possible with voice circuit Not possible with voice circuit switching technology switching technology
Internet radio, video on demand, Internet radio, video on demand, push Webpush Web
Content sitesContent sites Directing Web trafficDirecting Web traffic Complementing cache serversComplementing cache servers SecuritySecurity
IP Service Creation
1 - Physical
2 - Datalink
4 - Transport
5 - Session
6 - Presentation
7 - Application
ISO 7 Layer Model
3 - Network3 - Network
20
Optical Cross-connects (OEO)
DXC/DCS
SONET/SDHDigital Cross-connect (DXC) Also known as DigitalCross-connect Switch (DCS)
21
Optical Cross-connects (OEO)
DS-1 DS-3
ST
S-1
STS-N
AT
MD
S-3
STS-NATM STS-1
DS
-1
STS-N
ATM
DS
-1
DS-1
DS-3
ST
S-N
Electrical SwitchMatrix
SONET/SDHDigital Cross-connect (DXC) Also known as DigitalCross-connect Switch (DCS)
STS-N ATM DS-1 DS-3
22
All Optical Cross-connects (OOO)
OXC/PXC
All Optical Cross-connect (OXC) Also known as PhotonicCross-connect (PXC)
23
All Optical Cross-connects (OOO)
Optical SwitchFabric
3
2
2
4
4
1
1
3
All Optical Cross-connect (OXC) Also known as PhotonicCross-connect (PXC)
24
What is an OpticalCross-connect?
Connects one port (Connects one port () to ) to another portanother port
Add/Drop function with Add/Drop function with certain certain
Delivers high bandwidthDelivers high bandwidth Quick to provision bandwidthQuick to provision bandwidth
Port 3
Port 4
1
1
2
2
Port 2
Port 1
1 - Physical
2 - Datalink
4 - Transport
5 - Session
6 - Presentation
7 - Application
ISO 7 Layer Model
3 - Network
25
Reflector
MEMs tilting mirrors
Fibers
Imaging Lenses
OXC/PXC Switching Mechanisms
Micro-electrical Mechanical Micro-electrical Mechanical SystemsSystems
MEMsMEMs Used for many other applicationsUsed for many other applications
From Lucent, Corning, Xros From Lucent, Corning, Xros (Nortel), and others(Nortel), and others
Currently 8 x 8 OXC Currently 8 x 8 OXC 256 mirrors, long-term goal 1,024256 mirrors, long-term goal 1,024
OXCOXC ADM uses seesaw MEMSADM uses seesaw MEMS
Electrical controlsElectrical controls Voltage applied to mirror; tilts on Voltage applied to mirror; tilts on
2 axis + or – 6 degrees2 axis + or – 6 degrees
Switch times typically 10 to 25 msSwitch times typically 10 to 25 ms
26
OXC/PXC Switching Mechanisms
Liquid Crystal Light ValvesLiquid Crystal Light Valves From Spectra From Spectra
Switch and ChorumSwitch and Chorumtechnologiestechnologies
Switch speed Switch speed sub-millisecondsub-millisecond
Future switch Future switch speed in nanosecondspeed in nanosecond
1 x 2 port switch1 x 2 port switch 2 x 2 Add/Drop2 x 2 Add/Drop Electrical controlsElectrical controls
Input Output 1
Polarizing Beam
Splitter
ON
Liquid Crystal Cell
Polarizing Beam
Splitter
Liquid Crystal Cell
27
OXC/PXC Switching Mechanisms
Liquid Crystal Light ValvesLiquid Crystal Light Valves From Spectra From Spectra
Switch and ChorumSwitch and Chorumtechnologiestechnologies
Switch speed Switch speed sub-millisecondsub-millisecond
Future switch Future switch speed in nanosecondspeed in nanosecond
1 x 2 port switch1 x 2 port switch 2 x 2 Add/Drop2 x 2 Add/Drop Electrical controlsElectrical controls
Input
Output 2
Liquid Crystal Cell
Polarizing Beam
Splitter
Liquid Crystal CellOFF
Polarizing Beam
Splitter
28
OXC/PXC Switching Mechanisms
BubblesBubbles From AgilentFrom Agilent 32 x 32 or dual 16 x 32 ports32 x 32 or dual 16 x 32 ports Suitable forSuitable for
Wavelength Interchange Wavelength Interchange Cross-connect (WIXC)Cross-connect (WIXC)
Wavelength Selective Wavelength Selective Cross-connect (WSXC)Cross-connect (WSXC)
Optical Add/Drop Multiplexers Optical Add/Drop Multiplexers (OADM)(OADM)
Inkjet + Silica Planar Inkjet + Silica Planar Lightwave CircuitryLightwave Circuitry
Electrical controlsElectrical controls Bubbles created by heating Bubbles created by heating
“index matching fluid”“index matching fluid” Switch times under 10 msSwitch times under 10 ms
29
Developing an All OpticalPacket Router
NeedsNeeds How do you read a photonic header?How do you read a photonic header?
The “pipeline” approach?The “pipeline” approach? Switching and logicSwitching and logic
Current technology not fast enoughCurrent technology not fast enough Lithium Niobate devices have speed, Lithium Niobate devices have speed,
but too much crosstalkbut too much crosstalk Photonic Bandgap Devices Photonic Bandgap Devices
(optical equivalent to transistor)(optical equivalent to transistor) Buffering/MemoryBuffering/Memory
Optical buffers (fixed loop delays) exist, Optical buffers (fixed loop delays) exist, but are insufficientbut are insufficient
Bi-stable lasersBi-stable lasers Holographic memoriesHolographic memories SEEDS (Self Electro-optic Effect Devices)SEEDS (Self Electro-optic Effect Devices)
30
Agenda
History of IP BackbonesHistory of IP Backbones
The Emerging Two Layer NetworkThe Emerging Two Layer Network
Network PlatformsNetwork Platforms
Standards and ForumsStandards and Forums
GMPLSGMPLS
31
Operational Approaches:Overlay and Peer Models
Overlay modelOverlay model Two independent control planesTwo independent control planes
IP/MPLS routing IP/MPLS routing
Optical domain routingOptical domain routing
Router is client of optical domainRouter is client of optical domain
Optical topology invisible to routersOptical topology invisible to routers
Routing protocol stress – scaling issuesRouting protocol stress – scaling issues
Does this look familiar?Does this look familiar?
Peer modelPeer model Single integrated control planeSingle integrated control plane
Router and optical switches are peersRouter and optical switches are peers
Optical topology is visible to routersOptical topology is visible to routers
Similar to IP/MPLS modelSimilar to IP/MPLS model
?
32
Operational Approaches:The Hybrid Model
Hybrid modelHybrid model Combines peer & OverlayCombines peer & Overlay
Middle ground of 2 extremes Middle ground of 2 extremes
Benefits of both modelsBenefits of both models
Multi admin domain Multi admin domain support support
Derived from overlay Derived from overlay modelmodel
Multiple technologies Multiple technologies within domainwithin domain
Derived from peer modelDerived from peer model UNI
Peer
33
Standards and Industry Forums
Optical Internetworking Forum (OIF)Optical Internetworking Forum (OIF) Industry forumIndustry forum Kick-off meeting May 1998Kick-off meeting May 1998 Standard OIF UNI based Standard OIF UNI based
on IETF work (CR-LDP/RSVP)on IETF work (CR-LDP/RSVP)
Internet Engineering Task Force (IETF)Internet Engineering Task Force (IETF) Driving GMPLS standards developmentDriving GMPLS standards development
Initial application was MPlambdaSInitial application was MPlambdaS Peer model and Hybrid modelPeer model and Hybrid model Extend MPLS traffic engineering Extend MPLS traffic engineering
to the optical control planeto the optical control plane Rapid provisioningRapid provisioning Efficient restorationEfficient restoration
ITU-TITU-T Study Group 13Study Group 13 Study Group 15Study Group 15
34
IETF
GMPLS now Hosted by CCAMP WGGMPLS now Hosted by CCAMP WG Common Control And Measurement PlaneCommon Control And Measurement Plane
MPLS WG revised charter (without GMPLS)MPLS WG revised charter (without GMPLS) Eleven main GMPLS building blocksEleven main GMPLS building blocks
Internet DraftsInternet Drafts Current work includes extending existing control Current work includes extending existing control
protocols (example, OSPF & ISIS)protocols (example, OSPF & ISIS) New & future extensions consideredNew & future extensions considered
BGP4BGP4 For cross AS, and Carrier of Carriers applicationsFor cross AS, and Carrier of Carriers applications
LCASLCAS Link Capacity Adjustment Scheme protocol for SONETLink Capacity Adjustment Scheme protocol for SONET SONET Virtual Concatenation (dynamic TDM circuit control)SONET Virtual Concatenation (dynamic TDM circuit control)
Intent to submit work to ITU-TIntent to submit work to ITU-T
35
ITU-T
Study Group 13 (SG13)Study Group 13 (SG13) Focus: Multi-protocol & IP-based networks Focus: Multi-protocol & IP-based networks
& their inter-working& their inter-working Study Group 15 (SG15)Study Group 15 (SG15)
Focus: Optical & other transport networksFocus: Optical & other transport networks G.ASON – Automatically Switched Optical G.ASON – Automatically Switched Optical
NetworkNetworkAddresses the control layer for intelligent Addresses the control layer for intelligent
optical networksoptical networks
Ambition to reference IETF standardsAmbition to reference IETF standards
36
OIF Optical UNI Signaling
Uses procedures and messages defined for MPLS traffic Uses procedures and messages defined for MPLS traffic engineering and GMPLSengineering and GMPLS
FeaturesFeatures Runs in UNI-only mode (overlay model) Runs in UNI-only mode (overlay model) Optical path creation, modification, and deletionOptical path creation, modification, and deletion Optical path status inquiry and responseOptical path status inquiry and response
Allows one protocol to support two different Allows one protocol to support two different applicationsapplications OIF UNI: client bandwidth requests (hide optical topology)OIF UNI: client bandwidth requests (hide optical topology) GMPLS: service provider provisioning (expose optical topology)GMPLS: service provider provisioning (expose optical topology)
IETF-GMPLSOIF-UNI
OpticalTransmission
Network
UNI
UNI
UNI
UNI
UNI
UNI
37
Agenda
History of IP BackbonesHistory of IP Backbones
The Emerging Two Layer NetworkThe Emerging Two Layer Network
Network PlatformsNetwork Platforms
Standards and ForumsStandards and Forums
GMPLSGMPLS
38
Traditional MPLS Applications
Traffic Engineering
Layer 3 Routing Traffic Engineered LSP
Source Destination
VPNs
FT/VRS
Site 2
Site 3
Site 1
Site 1
Site 3
Site 2
CPE
CPE
CPE
PE PE
PE
P
P
P
P
P
PE
FT/VRF
FT/VRF
FT/VRF
FT/VRF
FT/VRF
CPE
CPE
CPE
FT/VRF
39
Generalized MPLS (GMPLS)
Traditional MPLS supports packet & cell Traditional MPLS supports packet & cell switching switching
Extends MPLS to support multiple switching Extends MPLS to support multiple switching typestypes TDM switching (SDH/SONET)TDM switching (SDH/SONET) Wavelength switching (Lambda)Wavelength switching (Lambda) Physical port switching (Fiber)Physical port switching (Fiber)
Peer modelPeer model Uses existing and evolving technologyUses existing and evolving technology Facilitates parallel evolution in the IP and optical Facilitates parallel evolution in the IP and optical
transmission domainstransmission domains Enhances service provider revenuesEnhances service provider revenues
New service creationNew service creation Faster provisioningFaster provisioning Operational efficiencies Operational efficiencies
40
GMPLS Mechanisms
IGP extensionsIGP extensions Forwarding adjacencyForwarding adjacency LSP hierarchyLSP hierarchy Constraint-based routingConstraint-based routing Signaling extensionsSignaling extensions Link Management Protocol (LMP)Link Management Protocol (LMP) Link bundlingLink bundling
41
IGP Extensions
OSPF and IS-IS extensions OSPF and IS-IS extensions Flood topology information among IP routers and OXCsFlood topology information among IP routers and OXCs New link typesNew link types
Normal link (packet)Normal link (packet) Non-packet link (TDM, Non-packet link (TDM, , or fiber), or fiber) Forwarding adjacency (FA-LSP)Forwarding adjacency (FA-LSP)
42
IGP Extensions
OSPF and IS-IS extensions OSPF and IS-IS extensions Flood topology information among IP routers and OXCsFlood topology information among IP routers and OXCs New link typesNew link types
Normal link (packet)Normal link (packet) Non-packet link (TDM, Non-packet link (TDM, , or fiber), or fiber) Forwarding adjacency (FA-LSP)Forwarding adjacency (FA-LSP)
43
IGP Extensions
New Link Type sub-New Link Type sub-TLVsTLVs
Link protectionLink protection Protection capabilityProtection capability AttributesAttributes
None, 1+1, 1:N, or None, 1+1, 1:N, or ringring
Priority for a working Priority for a working channelchannel
1:1 Protection
1:3 Protection
Working
Protection
Working
Protection
44
IGP Extensions
New Link Type sub-TLVsNew Link Type sub-TLVs Link descriptorLink descriptor
Characteristics of the linkCharacteristics of the link Selected attributesSelected attributes
Link typeLink type SONET, SDH, clear, SONET, SDH, clear,
Gig E, 10 Gig EGig E, 10 Gig E Minimum reservable bandwidthMinimum reservable bandwidth Maximum reservable bandwidthMaximum reservable bandwidth
Attributes change over timeAttributes change over time Provides a new constraint Provides a new constraint
for LSP calculationfor LSP calculation Shared Risk Link Group Shared Risk Link Group
(SRLG)(SRLG) List of the link’s SRLGs List of the link’s SRLGs Does not change over timeDoes not change over time
1:1 Protection
1:3 Protection
Working
Protection
Working
Protection
45
Forwarding Adjacency
A node can advertise an LSP into the IGPA node can advertise an LSP into the IGP Establishes LSP using RSVP/CR-LDP signalingEstablishes LSP using RSVP/CR-LDP signaling IGP floods FA-LSPIGP floods FA-LSP Link state database maintains conventional links and FA-LSPsLink state database maintains conventional links and FA-LSPs
A second node wanting to create an LSP can use an FA-LSP as A second node wanting to create an LSP can use an FA-LSP as a”link”a”link”in the path for a new, lower order LSP in the path for a new, lower order LSP
The second node uses RSVP/CR-LDP to establish label bindings for The second node uses RSVP/CR-LDP to establish label bindings for the lower order LSPthe lower order LSP
ATMSwitch
ATMSwitch
SONET/SDHADM
Ingress Node(High Order LSP)
Egress Node(High Order LSP)
FA-LSP
Ingress Node(Low Order LSP)
Egress Node(Low Order LSP)
SONET/SDHADM
46
Forwarding Adjacency
ATMSwitch
Ingress Node(High Order LSP)
Egress Node(High Order LSP)
Ingress Node(Low Order LSP)
Egress Node(Low Order LSP)
IGP attributes describing a forwarding adjacencyIGP attributes describing a forwarding adjacencyLocal (ingress) and remote (egress) interface IP Local (ingress) and remote (egress) interface IP
addressesaddressesTraffic engineering metricTraffic engineering metricMaximum reservable bandwidthMaximum reservable bandwidthUnreserved bandwidthUnreserved bandwidthResource class/color (administrative groups)Resource class/color (administrative groups)Link multiplexing capability (packet, TDM, Link multiplexing capability (packet, TDM, , or fiber) , or fiber)Path information (similar to an ERO)Path information (similar to an ERO)
ATMSwitch
SONET/SDHADM
FA-LSPSONET/SDHADM
47
LSP Hierarchy
FA-LSC
FA-TDMFA-PSC
BundleFiber n
Fiber 1
FSC CloudLSC
CloudTDM
CloudPSC
CloudLSC
CloudTDM
CloudPSC
Cloud
ExplicitLabel LSPs
Time-slotLSPs Fiber LSPs LSPs
ExplicitLabel LSPs
Time-slotLSPs
(Multiplex Low-order LSPs) (Demultiplex Low-order LSPs)
LSPs
Nesting LSPs enhances system scalability Nesting LSPs enhances system scalability LSPs always start and terminate on similar interface typesLSPs always start and terminate on similar interface types LSP interface hierarchyLSP interface hierarchy
Fiber Switch Capable (FSC) HighestFiber Switch Capable (FSC) Highest Lambda Switch Capable (LSC)Lambda Switch Capable (LSC) TDM CapableTDM Capable Packet Switch Capable (PSC) LowestPacket Switch Capable (PSC) Lowest
48
Constraint-based Routing
Reduces the level of manual configurationReduces the level of manual configuration Input to CSPFInput to CSPF
Path performance constraintsPath performance constraints Resource availabilityResource availability Topology informationTopology information
(including FA-LSPs)(including FA-LSPs)OutputOutput
Explicit route for GMPLS signalingExplicit route for GMPLS signaling
Extended IGPExtended IGP
RSVP SignalingRSVP Signaling
Explicit RouteExplicit Route
UserUserConstraintsConstraintsRouting TableRouting Table Traffic EngineeringTraffic Engineering
Database (TED)Database (TED)Constrained ShortestConstrained Shortest
Path First (CSPF)Path First (CSPF)
49
GMPLS Signaling Extensions
Label Related Formats (“Generalized Labels”)Label Related Formats (“Generalized Labels”)Generalized label requestGeneralized label request
Link protection type (none, 1+1, 1:N, or ring)Link protection type (none, 1+1, 1:N, or ring)LSP encoding type (packets, SONET, SDH, clear, DS-0, DS-1, LSP encoding type (packets, SONET, SDH, clear, DS-0, DS-1,
…)…)Generalized label objectGeneralized label object
Packet (explicit in-band labels)Packet (explicit in-band labels)Time slots (TDM)Time slots (TDM)Wavelengths (lambdas)Wavelengths (lambdas)Space Division Multiplexing (fiber)Space Division Multiplexing (fiber)
Suggested labelSuggested labelLabel can be suggested by the upstream nodeLabel can be suggested by the upstream nodeSpeeds LSP setup timesSpeeds LSP setup times
Label setLabel setRestrict range of labels selected by downstream nodesRestrict range of labels selected by downstream nodesRequired in operational networksRequired in operational networks
50
SONET/SDHADM
SONET/SDHADM
RESV
PATH
GMPLS Signaling Extensions
Bi-directional LSPsBi-directional LSPs Resource contention experienced by reciprocal LSP using separate Resource contention experienced by reciprocal LSP using separate
signaling sessionssignaling sessions Simplifying failure restoration in the non-PSC caseSimplifying failure restoration in the non-PSC case Lower setup latencyLower setup latency
RSVP notification messagesRSVP notification messages Notify message informs non-adjacent nodes of LSP eventsNotify message informs non-adjacent nodes of LSP events Notify-ACK message supports reliable deliveryNotify-ACK message supports reliable delivery
Egress controlEgress control Terminate LSP at a specific output interface of egress LSRTerminate LSP at a specific output interface of egress LSR
51
Link Management Protocol
The link between two nodes consists ofThe link between two nodes consists ofAn in-band or out-of-band control channelAn in-band or out-of-band control channelOne or more bearer channelsOne or more bearer channels
Link Management Protocol (LMP) Link Management Protocol (LMP) Automates link provisioning and fault isolationAutomates link provisioning and fault isolationAssumes the bi-directional control channel is always Assumes the bi-directional control channel is always
available available Control channel is used to exchangeControl channel is used to exchange
Link provisioning and fault isolation messages (LMP)Link provisioning and fault isolation messages (LMP)Path management and label distribution messages Path management and label distribution messages
(RSVP or CR-LDP) (RSVP or CR-LDP) Topology information messages (OSPF or IS-IS)Topology information messages (OSPF or IS-IS)
Control ChannelBearer Channel
LMP LMPLMP LMP
52
Link Management Protocol
Control channel managementControl channel management Lightweight keep-alive mechanism (Hello protocol)Lightweight keep-alive mechanism (Hello protocol) Reacts to control channel failuresReacts to control channel failures
Verify physical connectivity of bearer channelsVerify physical connectivity of bearer channels Ping test messages sent across each bearer channelPing test messages sent across each bearer channel
Contains sender’s label [(fiber, Contains sender’s label [(fiber, λ) pair] object λ) pair] object for channelfor channel Eliminates human cabling errorsEliminates human cabling errors
Link property correlationLink property correlation Maintains a list of local label to remote label mappingsMaintains a list of local label to remote label mappings Maintains list of protection labels for each channelMaintains list of protection labels for each channel
Fault isolationFault isolation ““Loss of light” is detected at the physical (optical) layerLoss of light” is detected at the physical (optical) layer Operates across both opaque (DXC) and transparent (PXC) Operates across both opaque (DXC) and transparent (PXC)
network nodesnetwork nodes
Services Provided by LMP
53
Multiple parallel links between nodes can be advertisedMultiple parallel links between nodes can be advertisedas a single link into the IGPas a single link into the IGP
Enhances IGP and traffic engineering scalabilityEnhances IGP and traffic engineering scalability Component links must have the sameComponent links must have the same
Link typeLink typeTraffic engineering metricTraffic engineering metricSet of resource classesSet of resource classesLink multiplex capability (packet, TDM, Link multiplex capability (packet, TDM, λλ, port), port)
(Max bandwidth request) (Max bandwidth request) (bandwidth of a component link) (bandwidth of a component link) Link granularity can be as small as a Link granularity can be as small as a λλ
Bundled Link 1
Bundled Link 2
Link Bundling
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GMPLS Benefits
Open standards allow selection of best-in-class Open standards allow selection of best-in-class equipmentequipment
Routers have visibility into the transmissionRouters have visibility into the transmissionnetwork topologynetwork topology Eliminates NEliminates N22 meshes of links scaling issue meshes of links scaling issue Reduces routing protocol stressReduces routing protocol stress Optical paths span an intermix of routers and OXCs to Optical paths span an intermix of routers and OXCs to
deliver provisioning-on-demand networkingdeliver provisioning-on-demand networking
Leverages operational experience with MPLS-TELeverages operational experience with MPLS-TE No need to reinvent a new class of control protocolsNo need to reinvent a new class of control protocols Promotes parallel evolution of UNI and NNI standardsPromotes parallel evolution of UNI and NNI standards Enables rapid development & deployment of new OXCsEnables rapid development & deployment of new OXCs
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GMPLS: Modern Thinking for Modern Times
Aligns with the way that the next generation network needs Aligns with the way that the next generation network needs to be built and managedto be built and managed
20th Century – Transmission network was dominant20th Century – Transmission network was dominant Voice ran over the transmission networkVoice ran over the transmission network ATM/Frame Relay delivered private data servicesATM/Frame Relay delivered private data services Internet was just one among many servicesInternet was just one among many services Transmission network created subscriber servicesTransmission network created subscriber services
21st Century – Internet is dominant21st Century – Internet is dominant Routers create the services that matter ($)Routers create the services that matter ($) Network must be optimized for IP/InternetNetwork must be optimized for IP/Internet OC-48/OC-192 make routers the largest consumers of bandwidthOC-48/OC-192 make routers the largest consumers of bandwidth New architecture is driven by routers subsuming functions New architecture is driven by routers subsuming functions
previously performed by the transmission networkpreviously performed by the transmission network The transmission network must evolve in a way that is most The transmission network must evolve in a way that is most
beneficial to the creation of Internet services beneficial to the creation of Internet services
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