Transcript Network of networks - ECE Engineering, U.Va.

Internet: Past, present, and future
Malathi Veeraraghavan
Univ. of Virginia
[email protected]
Sept. 25, 2015
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Basic networking concepts
Make it real: equipment, service providers
Drivers of networking research
TKDMPP
– Time, Knowledge, Data, Money, People, Processes
Mnemonic: Taekwondo - Massively Parallel Processor
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Communications vs. Networking
Transmitter (Tx)
Communication link
Receiver (Rx)
Transmitter (Tx)
Receiver (Rx)
Copper, Fiber or Air
Laptop
Laptop
Cell phone
Cell phone
Tablet
Tablet
Server
N endpoints. How many links?
Order N2
Switch
How many links do we need?
Server
Does every endpoint need
to communicate with all other
endpoints ALL the time?
No; Networks  Sharing
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Concept of multiplexing (sharing)
Sharing what? Link transmitter
Transmitter
at Laptop
is being shared
by Web flow and
Skype flow
Web
Client
Laptop
Skype
1001
routing software
Web
Server
local forwarding table
header value output link
0100
0101
0111
1001
3
2
2
1
Server
0100
3
destination address is
carried in arriving
packet’s header
Skype
Tablet
1
2
Switches
How many flows
can share a link?
Unlimited
What's the negative?
Each switch
has its own
forwarding table
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Insides of a switch
local forwarding table
dest. addr output link
B
Host A
Host B
B
A
Controller
Input ports
b
a
Demultiplexers
a
A
b
Host C
c
Host D
d
Space switch
Multiplexers
a
b
c
Output ports
B
A
Host A
Host B
d
Host C
Host D
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Network typically consists of
multiple switches
Routing protocol exchanges of
topology information: Between
controllers within switches
Destination Next-hop
E
D
B
3
C
5
2
A
3
1
2
1
F
2
D
1
Administrator-set
link weights
E
Routing protocol and Shortest-path computations: Distributed
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Internet(work): Network of networks
Gateways (IP routers)
Host
Switch
Switch
Interdomain
link
Host
Switch
Switch
Host
Host
Network 1
Owned and operated
by one organization
(e.g., UVA)
Network 2
Owned and operated by a
different organization
(e.g., AT&T)
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• Basic concepts understood
– Link
– Switch  Network: many switches
– Router  Internetwork: many networks
• Let's make these concepts real!
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Example of a 6' rack:
Two switches: each
- multiple line cards
- controller card
- space switch card
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Core (backbone) networks of the Internet


Phrase “owned and operated” – money and control
Center of Internet:




Small # of well-connected large networks
Tier-1 ISPs (e.g., Comcast, AT&T, NTT, China Telcom, Tata)
Large content distributors (Google, Yahoo, Microsoft)
Peers: No money exchanges; Roughly equal traffic
Tier 1 ISP
Large Content
Distributor
(e.g., Yahoo)
Tier 1 ISP
What is an ISP?
Large Content
Distributor
(e.g., Google)
Tier 1 ISP
Internet Service Provider
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Regional networks of the Internet
Tier-2 ISPs: smaller (often regional) ISPs
 connect to one or more tier-1 (provider) ISPs
 each tier-1 has many tier-2 customer nets
 tier-2 ISP pays tier 1 provider
Why purchase service from
second Tier-1 ISP?
Reliability
Tier 2
Tier 2 ISP Tier 2
ISP
ISP
Large Content
Distributor
(e.g., Akamai)
Tier 1 ISP
Tier 2
Tier 1 ISP
ISP Tier 2
Tier 2
ISP
ISP
Large Content
Distributor
(e.g., Google)
Tier 1 ISP
Tier 2
ISP
Tier 2
ISP
Tier 2
ISP
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Edge networks of the Internet

a packet passes throughmany networks from source
host to destination host
Campus, Corporate,
Residential networks
Tier 2
Tier 2 ISP Tier 2
ISP
ISP
Large Content
Distributor
(e.g., Akamai)
Tier 1 ISP
Tier 2
Tier 1 ISP
ISP Tier 2
Tier 2
ISP
ISP
Large Content
Distributor
(e.g., Google)
Tier 1 ISP
Tier 2
ISP
Tier 2
ISP
Tier 2
ISP
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10 Gbps
Backup: 2 Gbps
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Internet2: Tier1 ISP network
Inter-city links: 56 kbps in 1988; Today: 100 Gbps
100 Gbps links
Where is Ashburn, VA?
MARIA's router is located in Ashburn, VA
in the same building as an Internet2 router
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Who builds and sells network
switches/routers? Who buys them?
• Equipment vendors
– Switches and Routers: Cisco, Juniper, DLink, NetGear, Huawei, ZTE
– Optical switches: Ciena, Fujitsu
– Switch chipsets: Broadcom, Marvel
– Optoelectronic components? JDSU?
• Who buys this equipment: ISPs,
campuses, businesses, residences
• Capex (Capital expenditures) high
– Why? Closed systems unlike PC/Windows
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1.
2.
3.
4.
Ethernet Local Area Networks (LAN)
Wireless LANs  WiFi  IEEE 802.11
Cellular networks: 3G and 4G (LTE)
Residential access: Passive Optical Networks (PONs) and cable
(DOCSIS)
5. Data center networks: InfiniBand and FibreChannel
6. Wireless sensor networks: Zigbee, IEEE 802.15.4
7. Vehicular networks: IEEE 1609.3 over IEEE 802.11p
8. Satellite networks and disruption tolerant networks
9. Supervisory Control and Data Acquisition (SCADA) networks for
electric grid, water/sewage, etc.
10. IP-routed networks
11. Optical Wavelength Division Multiplexed (WDM) networks
12. Ethernet (Virtual LAN) switched networks
Core networks
Networks at the edges
Networking technologies: new ones
being invented all the time
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Drivers of networking research
Applications
Web
Who is Tim Berners-Lee?
Internet of Things
(scale just exploded)
Sensing+communications
technology
Data centers (why?)
Data center networks
(switches)
OpenFlow and
Software Defined
Networks (SDN)
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A Google Data Center
https://www.google.com/about/datacenters/inside/locations/
mayes-county/working-here.html
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“Real” Internet delays and routes
traceroute (tracert in Windows): umass.edu to eurecom.fr
Each row is a response
from a router on the path
Three delay measurements from
source host to first router cs-gw
1 cs-gw (128.119.240.254) 1 ms 1 ms 2 ms
2 border1-rt-fa5-1-0.gw.umass.edu (128.119.3.145) 1 ms 1 ms 2 ms
3 cht-vbns.gw.umass.edu (128.119.3.130) 6 ms 5 ms 5 ms
4 jn1-at1-0-0-19.wor.vbns.net (204.147.132.129) 16 ms 11 ms 13 ms
5 jn1-so7-0-0-0.wae.vbns.net (204.147.136.136) 21 ms 18 ms 18 ms
6 abilene-vbns.abilene.ucaid.edu (198.32.11.9) 22 ms 18 ms 22 ms
7 nycm-wash.abilene.ucaid.edu (198.32.8.46) 22 ms 22 ms 22 ms trans-oceanic
8 62.40.103.253 (62.40.103.253) 104 ms 109 ms 106 ms
link
9 de2-1.de1.de.geant.net (62.40.96.129) 109 ms 102 ms 104 ms
10 de.fr1.fr.geant.net (62.40.96.50) 113 ms 121 ms 114 ms
11 renater-gw.fr1.fr.geant.net (62.40.103.54) 112 ms 114 ms 112 ms
12 nio-n2.cssi.renater.fr (193.51.206.13) 111 ms 114 ms 116 ms
13 nice.cssi.renater.fr (195.220.98.102) 123 ms 125 ms 124 ms
14 r3t2-nice.cssi.renater.fr (195.220.98.110) 126 ms 126 ms 124 ms
15 eurecom-valbonne.r3t2.ft.net (193.48.50.54) 135 ms 128 ms 133 ms
16 194.214.211.25 (194.214.211.25) 126 ms 128 ms 126 ms
17 * * *
* means no response (probe lost, router not replying)
18 * * *
19 fantasia.eurecom.fr (193.55.113.142) 132 ms 128 ms 136 ms
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Compute propagation delay
• How long does it take to transfer one
bit from New York to Paris?
• What's the distance? 5834 km
• What's the speed of light in fiber:
roughly 2105 km/sec
• What's the answer: one-way: 29ms
• Round-trip prop. delay: 54ms
• Queueing delays, etc.: 106ms
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How does Google make its money?
• Advertising: Need to be within 50-ms of all eyeballs
• "The human eye's threshold for perceiving latency is about
50ms. Crudely simplified, this means that if you render a
screen within 50ms or less, it's going to be perceived as
instantaneous. If it takes longer, people can sense the
latency. Lots of subliminal processing occurs on an image in
the first 250ms, with conscious processing happening after
270ms."
http://www.skrenta.com/2007/11/ranking_web_20_sites_by
_server.html
– Caveat: UNVERIFIED!
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The birth of the datacenter
• Many round-trip times (RTTs) incurred to
support a Web browsing session
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Name to IP-address lookup
Connection setup delay (client-to-server)
Web page request and response
Browser will parse page and then send requests
for images in the page.
– Very chatty - many exchanges between client
and server
• Having datacenters in major cities around
the globe allows Google to cut RTT
ping www.virginia.edu and also ping www.google.com
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Cost of switches
• Recall the controller within the switch
• What did it run?
– Routing protocol and shortest-path
computation to create forwarding tables
• Who can modify that software?
– Only the switch equipment vendor (Cisco)
– Why?
– Cisco switch uses closed software model
unlike Windows PC
– Software developer salary: major cost
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How many switches
are needed in a datacenter?
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One million computers
Assume each switch has 50 ports
Need 20,000 switches
Each switch costs $50K. Cost adds up!
Drive the cost of switch down by removing
software
• Google said our own developers can write that
routing protocol software and run it on a
centralized host (one of their own datacenter
hosts)
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Software Defined Network (SDN)
Championed by Google
(ii) Run Shortest-Path Algorithm
Compute forwarding tables for all switches
(i) Collects topology info
(iii) Write forwarding
tables to each switch
OpenFlow
Switch
Complex routing protocol sofware removed from switch controller
thus lowering cost of switch; Standardized OpenFlow protocol
https://www.lkn.ei.tum.de/fileadmin/tueilkn/sdn.PNG
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Hot research areas
• OpenFlow/SDN
– Turned the networking world upside down
– Distributed protocols had been the mantra
for 30+ years! Now it is centralized
– What happens to Security? Reliability?
– How do SDN controllers owned and
operated by different networks
communicate?
• Data-center networks:
– Power consumption; Failures; Wiring
• Internet of Things (IoT)
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Impact of Networks:
World is Flat
• Book by Tom Friedman
• Global Crossing and Wall Street
• India, China, old Soviet States
– Accounting, Call Centers, Radiology, Law, Banking
• What will be the impact of IoT, networked
robotics, and remote haptics?
• Protectionism by governments vs. capital
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Time, Knowledge, Data, Money,
People, Processes (TKDMPP)
Knowledge: Next Slide
Data
Read Moneyball?
Money
Why did MichelAngelo leave
behind unfinished sculptures?
People
Still think
Romains
is correct?
Harry Truman:
“The 'C' students run the world.”
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Importance of knowledge
(Ed Hirsch, UVA)
Shoulders
of giants
(Isaac
Newton)
http://uvamagazine.org/articles/the_facts_of_the_matter
Eureka!
New
Data
Fundamental challenge: Uploading data into human memory
Loreto Peter Alonzi, Talk at UVA, 2014-07-24
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Summary
• Networking sits between EE
hardware and CS software
– We are engineers; important to know the
hardware, software or system that your
research targets
• OpenFlow/SDN: Stanford and Google
– Academia + Industry partnership impt.
• Build, test, prove and sell
• TKDMPP
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