An SAIC Company Slide 1. Gigabit Ethernet: Is it a disruptive technology? Ronald Skoog Telcordia...
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Transcript of An SAIC Company Slide 1. Gigabit Ethernet: Is it a disruptive technology? Ronald Skoog Telcordia...
An SAIC CompanySlide 1.
Gigabit Ethernet: Is it a disruptive technology?
Ronald SkoogTelcordia [email protected]
LTS
LTS©Telcordia Technologies, Inc. Slide 2
Outline
Background: – The Metro Network Environment and the Technology Choices
Ethernet and Gb/10Gb Ethernet Technology Background
Gb/10Gb Ethernet Capabilities and Deficiencies
Related Standards and Industry Forum Activities and Service Providers
Conclusions and Summary
LTS©Telcordia Technologies, Inc. Slide 3
Metro Network Environment
LAN Internetbackbone
LAN
ISPPOP
ISPPOP
ASPSSP
MAN
BOTTLENECK!!• SONET-based TDM networks• Inefficient for data traffic
• stranded capacity, • no statistical gain
• Long provisioning times
Business Services/Apps– Access to Internet, ASPs, SSPs, etc. – LAN-LAN, VLANs, VPNs– Flexible, granular bandwidth choices– Quick and efficient service provisioning – Voice and video
Residential Services/AppsxDSL, Cable, ETTH HDTV VideoGamesVoice
Residential
LTS©Telcordia Technologies, Inc. Slide 4
New Alternatives to SONET
Next Generation MANNext Generation MAN
WDMWDM
LAN Internetbackbone MANMAN LAN
LAN
ISPPOP
ISPPOP
MSPPNG SONET
(VC, GFP)
GigabitEthernetNew Solutions
RPR DPTiPT
ATMVP Ring
MANMAN-nDS0, T1, T3Leased line- TDM-based
SONET
Residential
Bottleneck
!
LTS©Telcordia Technologies, Inc. Slide 5
Ethernet Protocol Structure
Data Link
Application
Presentation
Session
Transport
Network
Physical
OSI Model
Layer 7
Layer 6
Layer 5
Layer 4
Layer 3
Layer 2
Layer 1
Major IEEE Sublayers
Ethernet-Specific
802.2
802.3
802.1D 802.1Q802.1p
Ethernet Frame Structure
PreambleDestination
MACAddress
SourceMAC
Address
Length/Type
Data/LLCFrameCheck
Sequence
64 bits 48 bits 48 bits 16 bits 46 to 1500 Bytes 32 bits
1518 Bytes Length 64 Bytes
Physical Signaling
Media
MAC Bridging
Media Access Control(MAC)
Logical Link Control(LLC)
LTS©Telcordia Technologies, Inc. Slide 6
Evolution from Shared-Media, Half-Duplex to Dedicated-Media, Full-Duplex
10BASE2 or 10BASE5 (Coax Cable, Bus Topology, 1985)
Collision (CSMA/CD resolution)
Collision (CSMA/CD resolution)Repeater
UTP
UTP
UTP
UTP
Half-Duplex 10BASE-T (Star Topology, UTP cable, 1990)
Dedicated Media
Bridge/Switch
Full Duplex 10/100BASE-T (1992/1993) Collision-Free
UTP UTP The Critical Development• LAN backbone and NIC speeds are independent• Networking is now possible
LTS©Telcordia Technologies, Inc. Slide 7
Switched GbE Network Architecture
LAN 1
LAN 2
LAN n
• • •
Multi-Tenant Unit Building (MTU)
Access GbESwitch Core GbE
SwitchedNetwork
GbE GbE
IP BackboneProviders
Access GbESwitch
GbE
ServerFarm
GbE
Multi-tenantBuilding
Multi-tenantBuilding
Multi-tenantBuilding
ASPs
ISPs
GbE Architecture
GbE L2Switch
GbE L2/3Switch
Optical Ethernet Service Categories• Internet access• LAN-LAN Interconnection (Ethernet PL)• Metro Transport (Transparent LAN Service)
LTS©Telcordia Technologies, Inc. Slide 8
GbE and SONET Network Architectures
LAN 1
LAN 2
LAN n
• • •
Multi-Tenant Unit Building (MTU)
Access GbESwitch Core GbE
SwitchedNetwork
GbE GbE
IP BackboneProviders
Access GbESwitch
GbE
ServerFarm
GbE
Multi-tenantBuilding
Multi-tenantBuilding
Multi-tenantBuilding
ASPs
ISPs
GbE Architecture
SONET Architecture
RFT
RFT
RFT
Office
TM
DS0-DS3
OC3OC12
ADM
OC12OC48
DCS ADM(hub)
OC48Collector
Ring
OC12OC48
DCS ADM ADM
CoreRing
IXC
ATM
ISP
OC3-OC12
GbE L2Switch
GbE L2/3Switch
LTS©Telcordia Technologies, Inc. Slide 9
10 Gigabit Ethernet Layer Architecture
• At Layer 2, 10 GbE is mostly unchanged, except NO SHARED MEDIA
• Two Physical (PHY) Layers: LAN PHY and WAN PHY
• Multiple Physical Media Dependent (PMD) layers: – MMF and SMF– Minimum distance requirements from 65 m to 40 km
802.3 Media Access Control
Reconciliation
PCS
XGMII
WIS
PMA
PMD
PMA
PMD
MDI MDIMedium
(Optical Fiber)LAN PHYWAN PHY
850 nm Serial (MMF)1310 nm Serial (SMF)1550 nm Serial (SMF)1310 WWDM Parallel (MMF, SMF)
PHY
64B/66B coding for Serial PMDs8B/10B coding for WWDM PMD
SONET framer
LTS©Telcordia Technologies, Inc. Slide 10
10 GbE Applications
Metro Network
Core Routers
EdgeRouters
Access Routers• • •
DWDM
Long Haul Network
Server Farm Connectivity
Long Haul LinksWAN PHY Core Routers
10GbE
GbE
10GbE
10 GbE10 GbE
10GbE
10GbE
10GbE
• • •
Regional/Metro
Access Routers
Edge/CoreRouters
10GbEGbE
10GbE
10GbE
ELTE*
WIS Path
* ELTE = Ethernet Line Terminating Equipment
LTS©Telcordia Technologies, Inc. Slide 11
Gb/10Gb Ethernet Capabilities
Full duplex point-to-point links with long reach to 40 -70 km
Big port cost advantage over SONET and ATM (~8:1 in port costs)
‘Plug-and-play’
VLAN capability (802.1Q)
Spanning tree routing (802.1D) at layer 2
Aggregate link capability (802.3ad)
Priority capability (aggregate flow QoS) provided by 802.1p at Layer 2 and DiffServ at layer 3
Policy based QoS
Traffic policing, shaping and monitoring at customer interface
Optical Ethernet has a significant arsenal of Networking Capabilities
LTS©Telcordia Technologies, Inc. Slide 12
Gb/10Gb Ethernet Deficiencies Protection/restoration times are on the order of 1 second
compared to SONET 50 ms capability
QoS is in a similar state as IP QoS– over-provisioning needed to provide delay/jitter sensitive apps.
– QoS provided for traffic aggregates, not individual flows
– Routing protocols don’t balance load very well on link capacity
Performance monitoring and fault management are not as good as SONET and ATM.– Ethernet provides no overhead for performance monitoring,
alarms, protection signaling, etc. 10GbE WAN PHY has some of this capability
Not clear how well GbE OA&M will scale (e.g., service provisioning, loopbacks, single-ended maintenance)
LTS©Telcordia Technologies, Inc. Slide 13
Missing OAMP Functionality in Ethernet
Fault Detection, Sectionalization, and Alarming
Protection and Restoration (SONET: 50msec)
Secure Single-Ended Maintenance
PHY-Layer Link Quality Monitoring (BER)
Loopbacks
LTS©Telcordia Technologies, Inc. Slide 14
Why is Ethernet Cheaper?
Simple Technology Backwards Compatibility Strict Standardization and Interoperability Customer Familiarity and Acceptance Large Volumes
ELECTRONICS:Byte-orientedLine coding (e.g, 8B10B)Simple frame delineationRelaxed timing and Jitter
OPTICS:High-Volume, Mass AssemblyPlastic Packaging
Source: Martin Nuss,Internet Photonix
LTS©Telcordia Technologies, Inc. Slide 15
Spanning Tree Capability (802.1D)
Routing in layer 2 switched networks uses the spanning tree algorithm– spanning tree routing is prone to traffic concentrating on a small
number of links and switches;– spanning tree reconfiguration is relatively slow (30-50 seconds
required);• An improved algorithm is being developed (P802.1w) that will
converge in < 1 sec. (maybe in 10s of ms)• Multiple spanning tree capability is being developed in P802.1s
L2Switch L2
Switch
L2Switch
L2Switch
L2Switch
LAN
LAN
LAN
LAN
LAN
Spanning Tree Links
SWITCHES LEARN TOPOLOGY BY EXCHANGE OF CONFIGURATION MESSAGES
L2Switch
LTS©Telcordia Technologies, Inc. Slide 16
Virtual LAN (VLAN) Capability
Virtual LAN and priority capabilities are provided by 802.1Q/p:– a VLAN tag is provided by 802.1Q to identify VLAN membership
Limited to 4096 VLANs – this is a potential scalability issue
– the VLAN tag has a 3-bit priority field that allows 8 possible service classes (matches DiffServ’s 8 possible classes)
Why VLANS?– LAN scalability:
limits broadcast domains (limits broadcast storms); also limits multicast, chatty protocols, etc., reducing overall network traffic.
– Network efficiencies: traffic flows from different VLANS can be segregated
– Allows non-physical grouping of nodes that share similar resources
– Allows easy changing of LAN membership
– Reduces the amount of level 3 (IP) routing
– Security: limits snooping; authentication required (via GVRP) to join VLAN
LTS©Telcordia Technologies, Inc. Slide 17
VLANs and MPLS-Based Transparent LAN Services
LER
LER
LSRLSR
LSR
LER
LER
LERLER
CPE
CPE
CPE
CPECPE
B
A
A
A
B
VC LSP
Tunnel LSP
VC LSPEthernetVLAN
EthernetVCLabel
TunnelLabel
Etype0x8847
DA SA
Original Ethernet
Frame
Label StackOuterEthernet Header
32 bits16 bits16 bits
PreambleDestMAC
Address
SourceMAC
Address
64 bits 48 bits 48 bits
Length/Type
Data/LLCFrameCheck
Sequence
16 bits 46 to 1500 Bytes
TPID TCI
User Priority (3)
CFI(1)
VLAN ID (12)
Architecture based on Martini IETF Draft
LTS©Telcordia Technologies, Inc. Slide 18
Related Standards and Industry Forum Activities
Resilient Packet Ring (RPR) – IEEE 802.17– Data efficient ring (distributed switch) using spatial reuse, 50 ms
protection, and bandwidth management (allocation and fairness)
Ethernet in the First Mile (EFM) Study Group – IEEE 802.3ah– Remote management of customer terminal for testing (loopbacks)
– Link OAM overhead for BER monitoring, alarm indication, etc.
ITU Study Group 13 (Multi-Protocol and IP-based Networks & ...) – Link OAM and end-to-end OAM
– Leverage link OAM from EFM
Metro Ethernet Forum (Industry Alliance)– Ethernet service definitions, technical specifications, and interoperability
– MPLS protection mechanisms to 50 ms protection
– OAM&P is on the agenda (leverage EFM link OAM work)
LTS©Telcordia Technologies, Inc. Slide 19
Service Providers with Ethernet Services/Plans
WorldComLevel 3
Williams Communications
SprintGlobal Crossing
AT&TBroadwing
Traditional IXCsEmerging IXCs
Telseon
XO CommunicationsSphera
Time Warner TelecomOnFiber
Group Telecom (Canada)Looking Glass
Electric LightwaveEPIK Communications
Full Service CLECSEmerging metro/regional carriers
Verizon
SBC CommunicationsYipes
QwestIntelliSpace
BellSouthFiber City
Bell CanadaCogent
ILECSELECS
WorldComLevel 3
Williams Communications
SprintGlobal Crossing
AT&TBroadwing
Traditional IXCsEmerging IXCs
Telseon
XO CommunicationsSphera
Time Warner TelecomOnFiber
Group Telecom (Canada)Looking Glass
Electric LightwaveEPIK Communications
Full Service CLECSEmerging metro/regional carriers
Verizon
SBC CommunicationsYipes
QwestIntelliSpace
BellSouthFiber City
Bell CanadaCogent
ILECSELECS
Source: RHK Inc.
LTS©Telcordia Technologies, Inc. Slide 20
Is Gigabit Ethernet a Disruptive Technology?
It has a huge cost advantage– ~8-to-1 in port costs, less in provisioning and operations
Currently serving niche markets – Internet access at 20%–30% equivalent SONET $/bps prices
– IP-based (iSCSI) SAN or data backup solution for smaller sites giving them Fibre Channel like performance
No ‘killer’ issues have been identified There will always be gaps in capabilities,
– but they are getting smaller, and
– closing the gap may not be worth the price
We believe that GbE is likely to be a Disruptive Technology
LTS©Telcordia Technologies, Inc. Slide 21
Conclusions
The main contenders are Gb/10Gb Ethernet, MSPP technologies and RPR technology.– The MSPPs and RPRs may become more Ethernet-based
– The SONET-based MSPPs and RPRs may have more competitive cost structures
But, GbE Technology will be a Major Player
There is a Race going on at the Optical Edge
It is not clear which technology direction will prevail– Is multi-service/Multi-protocol capability needed, or will
Ethernet become the ubiquitous layer 2 standard?
There is no one answer for all networks– Options need to be carefully considered for each carrier and
service provider