cs6591 communication network analysis and design · from ieee 802.3-2012 section 4. xgmii: a hw...
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CS6591 Communication Network Analysis and Design
Dr. Greg Bernstein
Multiple sources…
www.grotto-networking.com
Outline
• Why bother with network “concepts”?
• Initial Concepts:– “multiplexing”
– “inverse multiplexing”
– Switch “forwarding table”
– “control”, “management”, FCAPS
– “layers” and “partitions”
• Standards and Networking
• Networking isn't just IP...
Voice Hierarchies
• 64kbps were the foundation of the digital telephone system.
• Two major multiplexing hierarchies evolved from these DS0 channels. – The T1 hierarchy (https://en.wikipedia.org/wiki/T-carrier) and
the E1 hierarchy (https://en.wikipedia.org/wiki/E-carrier). – These hierarchies are more accurately referred to as PDH
(plesiochronous digital hierarchies). Exact specifications of some of these systems can be obtained free from the ITU-T (http://www.itu.int/rec/T-REC-G/e). In particular G.701-705.
• But wait voice communications is still alive and well and actually starting to sound better? – Yes, but we have largely abandoned 64kbps channels as a
foundation for networking!
Why bother with “concepts”?
• “Concepts”, “Abstractions”, and “Generalizations” in Networking: Why?
– Which is older circuit switching or packet switching? How old is networking? What is the biggest network in terms of $$$ traded?
– Origins of routing protocols
– The patent “game”
– Understanding a continuously changing field
“Package" Switching Example
• Daily Flight Segments: Domestic - 940; International - 1, 015
Airports Served: Domestic - 382; International - 346
Air Hubs:– United States: Louisville, KY (Main Global Air Hub); Philadelphia, PA;
Dallas, TX; Ontario, CA; Rockford, IL; Columbia, SC – Europe: Cologne/Bonn, Germany – Asia Pacific: Shanghai; Shenzhen; Hong Kong – Latin America and Caribbean: Miami, FL, USA – Canada: Hamilton, Ontario
UPS Air Operations
Largest $$$ Network in TradeC
on
tain
er
Sh
ippin
g
Ne
two
rk
s
From the Economist website
Container Shipping “Links”• Trade route information:
http://www.worldshipping.org/about-the-industry/global-trade/trade-routes
Origins of Routing Protocols and Queueing Theory
• The founders of the internet didn't invent the concept of “routing”! – Shortest path algorithms such as Bellman-Ford (1956)
– RIPv2-- and Dijkstra's algorithm (1959) –OSPF--came well before the internet! T-carrier didn't start to be deployed until 1962.
• Queueing theory – (https://en.wikipedia.org/wiki/Queueing_theory) goes
back to Markov (1906) and Erlang (1906 etc...). But we can use it over 100 years later to tell us about the packet delays in an IP router, or the dropping (on handoff) of a cellular phone call.
Understanding a continuously changing field…
• X.25 (1970)
• Frame Relay (1988)
• Asynchronous Transfer Mode (1990s)
• MPLS (1996, first RFCs 2001)
• What do these all have in common?
Networking Concepts
• Multiplexing
• Inverse multiplexing
• Data Plane
– Switch forwarding tables
• Control and Management Planes
• Layers and Partitions
Multiplexing
• N communicating entities
– Need N(N-1) unidirectional comunicaiton channels
Time Division Multiplexing Details
From ITU-T G.704
What’s this course about?
• Current topics and concepts in high speed networks!
• Contents have been changing based on evolving technologies and application areas.
• Hence we will cover :– Technologies and concepts: VPNs, MPLS, Optical,
GMPLS, advanced switches and router design, SDN, queueing theory/QoS
– Application areas: Data centers (cloud), enterprise, ISPs, carrier backbone
Time Division Multiplexing Details (icky!)From ITU-T G.704
FDM Free Space
spectowval.com
ptolemy.eecs.berkeley.edu
FDM in FiberFrom ITU-T G.694.1
https://en.wikipedia.org/wiki/Fiber-optic_communication
Try a quick check with c = 3.0e8 m/s
Inverse Multiplexing
• Concept
– Using multiple lower rate channels to create a single higher rate channel.
– Derives from idea of parallel processing
• Variations
– End to end, single hop
– Circuits or packets
– Layer: 1, 2, 3, or 7
VCAT Inverse Multiplexing
• Circuit based
• End-to-End
b1 b2 b3 b4 b5 b6
Ethernet Link Ethernet Link
Ethernet Packet
VCAT Member # 1
VCAT Member # 2
VCAT Member # 3
VCAT Ingress VCAT Egress
Transport Network
b1 b4
b2 b5
b3 b6
b1 b2 b3 b4 b5 b6
Ethernet Packet
The PPP Multilink Protocol RFC1990
• http://tools.ietf.org/html/rfc1990
BitTorrent (application layer)
• http://bittorrent.org/introduction.html• https://wiki.theory.org/BitTorrentSpecification
Conventional server approach
BitTorrent peer to peer approach
Ethernet LAG (802.1AX-2008)
Ethernet LAG (802.1AX-2008)
Ethernet LAG (802.1AX-2008)
Networking & Standards
• IETF RFCs– http://www.ietf.org/
• IEEE Standards– http://standards.ieee.org/about/get/
• ITU-T Recommendations– http://www.itu.int/en/ITU-
T/publications/Pages/recs.aspx
• Many others…– MEF, ONF, OIF, ETSI, ANSI, …
Uses of Layers in Networks
• Interoperability points– Physical and logical
• Management– Fault isolation, Performance monitoring (where
did the errors occur)
• Multiplexing and Switching– How signals/bits/bytes/packets get combined and
forwarded
– Not just one switching layer!!!
OSI Layer Models
– Useful for understanding data communication protocol relationships– Not really the full story…– https://en.wikipedia.org/wiki/OSI_layer
TCP/IP Layer Model
• Application• Transport
– TCP, UDP
• Internet– IPv4, IPv6
• Link• No physical?
– Flexibility to use different phylayers
https://en.wikipedia.org/wiki/TCP/IP_model
10G Ethernet Layer Model
• From IEEE 802.3 (2012) Section 4• Available from http://standards.ieee.org/about/get/• Why the extra layers/sublayers? PCS, PMA, PMD, XGMII
XGMII
• What is this?
• 10 Gigabit Media Independent Interface
– A SerDesH/W interface
From IEEE 802.3-2012 section 4
XGMII: A HW Layer/Interface
Nice 32 bit wide data busesFrom IEEE 802.3-2012
section 4
SDH/SONET Layers• ITU-T G.707 “Network node interface for the synchronous digital hierarchy (SDH)”• Available from http://www.itu.int/ITU-T/recommendations/rec.aspx?rec=8981• Why all these layers?
– Multiplexing/Switching and Management!
VT Path
STS Path
Tandem Connection
(optional)
Line
Section
Physical
Lower order
Virtual Containers
Higher order
Virtual Containers
Tandem Connection
(optional)
Multiplex Section
Regenerator Section
Physical
(a) SONET (b) SDH
Layers in TDM Networks
Regenerator
(3R) #1
Regenerator
(3R) #2
TDM de-
multiplexor
TDM
Multiplexor
= Optical Fiber
= Regenerator section overhead
= Multiplex section (line) overhead
= User traffic (path layer)
= Unused time slots
Path
MS
RS RS RS
Path
MS
RS
TDM Path
Multiplex Section
Regenerator
Section
TDM = Time Division Multiplexing like SONET, SDH, PDH, G.709, etc…
Optical Transport Network Layers
From ITU-T G.709
Layers in WDM Networks
Optical
Amplifier #1
Optical
Amplifier #2
Optical Add/
Drop
multiplexor
Optical
Multiplexor
Optical De-
multiplexor
= Optical Fiber
= Optical Support Channel
for “Transport layer”
= Optical Support Channel
for “multiplex layer”
OCh
OMS
OTS OTS OTS
OCh
OMS
OTS
OCh
OMS
OTS
Optical Channel
Optical Multiplex
SectionOptical Transport
Section
“Domains” – partitions of networks
• General Internet
– Autonomous Systems
• Intra-Domain Routing
– OSPF Areas
• Ethernet “LANs”
– Broadcast domains for Ethernet switches
• Link
– Between two nodes
Subnetwork Terminology
Network
Subnetwork C
C1
C2
C3
C4
C6
C7
C8
C9
C10
Subnetwork B
B1
B2
B3
B4
B6
B7
B8
End
system
A
End
system
ZLink
Node or
Network Element (NE)
Layers and Partitions
• Formal Models– ITU-T
• G.805• G.800• http://www.itu.in
t/ITU-T/recommendations/index.aspx?ser=G
– Open Grid Forum• Network Markup
Language• http://www.ogf.o
rg/documents/GFD.206.pdf
Ethernet Review• Reference Model (IEEE 802-2001)
Ethernet Frame
SFD = start of frame delimiter
IEEE 802.3-2012 part 1
Ethernet Addresses• Individual/Group• Unique/Locally Administered• First 24 bits form the Organizationally Unique Identifier (OUI)
From IEEE 802-2001
Ethernet Bridging
• Applies to “MAC” sublayer of layer 2
From IEEE 802-2001