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Internet Trends and the Cost of Connectivity
1st BroadSky Workshop, Lacco Ameno, Italy November 6, 2003
Will Ivancic – [email protected]
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Experimental Satellites (70s – early 90s) Maintain US preeminence in satellite communication Focused on Commercial Communications Satellites
Space Communications (mid 90s +) NASA Mission Focused
Earth Science Computer Information and Communications Technology
(CICT) Human Exploration and Development of Space
Aeronautics (2000 +) Capacity (Air Traffic Management) Safety (Weather and Security)
NASA Glenn’s Space Communications Program
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Aeronautics Communications, Navigation, and Surveillance (Low
Data-Rate Requirements) Delivery via VHF and/or Satellite Command and Control requires a reliable transport protocol Current protocols
Aircraft Communications Addressing and Reporting System (ACARS)
Aeronautical Telecommunication Network (ATN) Moving Toward IPv6 (commercial standards)
Weather (Low Data-Rate Requirements) Possible use of multicasting and broadcasting protocols Low Bandwidth requirements May use non-reliable transport protocols (no feedback)
Others (Medium to High Data-Rate Requirements) Entertainment Maintenance Video Surveillance Black Box Data eBusiness (Records, manuals, maps, etc…)
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Transmission Control Protocol (TCP) Currently the Dominant Reliable Transport Protocol in
the Internet Designed to be fair and operate over shared
infrastructure (Congestion Dominates most end-to-end links)
Slow Start (Exponential Increase) to probe for bandwidth Rate Halving when packet is lost (Multiplicative Decrease) Rate Increase by 1 packet per round trip (Additive
Increase) Parameters Affecting Throughput
Bandwidth-Delay Product Congestion Errors File Size
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Round Trip Time (RTT) Delay US to Japan Terrestrial
20 – 100 msec GEO Satellite
550 msec (Theory) Real Systems 0.8 - 1.5 sec
802.11 Wireless Ethernet Negligible (Network Delay Dominates)
G2 / G3 Cellular ~1 Second using General Packet Radio Services
(GPRS) from T-Mobile LEO
~1 – 2.5 Seconds (Using Globalstar)
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Performance Enhancing Proxies (PEPs)
Middleware deployed to help TCP performance over links with large bandwidth-delay products
Attempt to optimize control loops Often breaks end-to-end architecture
If so, breaks end-to-end reliability (at lease at the transport layer)
Difficulty working with Security (IPSec, Virtual Private Networks)
Internet Internet
Control Loop 1 Control Loop 3Control Loop 2
End-to-End Control Loop
PEPs
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Reliable Transport Protocol Developments TCP Swift Start
Improves Slow Start Performance TCP Westwood
Attacks Additive Increase, Multiplicative Decrease (AIMD) problem
Cumulative Explicit Transport Error Notification Attacks Additive Increase, Multiplicative Decrease
(AIMD) problem Stream Control Transport Protocol (SCTP)
New Reliable Transport Protocol Incorporates many proposed improvements to TCP
Byte Counting Selective Acknowledgements Non-Blocking of multiple streams
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Internet Trends Inexpensive Broadband Connectivity
Cable Modem, DSL, WiFi, G2.5/G3/G4 Always On Connectivity Peer-to-Peer networking
Symmetric Links (no longer highly asymmetric) Conversation may be initiated from outside your network!
eBusiness Web replaces paper forms (e.g. eNASA, eCoast Guard)
Network Centric Warfare Mobile Networking
Maintain connections when crossing networks IPv6 Security
Network Address Translation and Proxies can really mess things up, but are probably here to stay.
Ad Hoc Networking
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What is Mobile-IP and Mobile Networking? Mobile IP is a routing protocol that
enables IPnodes (hosts and routers) using either IPv4 or IPv6 to seamlessly “roam" among IP subnetworks. Supports transparency above the IP layer,
including the maintenance ofactive TCP connections and UDP port bindings.
Link Independent Supports Multi-Homing (connections to more
than one route and/or media type)
Mobile Router uses
FAPort A
NOC HA Carnival Cruise
FA
FAPortB
Ethernet Ethernet
Time
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Military Applications
AWACS
UAV
Intelligence Control Center
Battle Group Command Center (BGCC)Battle Group Command Center (BGCC)
Home-Agentdeployed inBGCC
Foreign-Agentdeployed in UAV
Foreign-Agent deployed in Tracked Command Post Carrier.Unit deployed in vicinity of the battlefield.
Tactical data forwarded from surveillance satellites to the BGCC.
Communications link between BGCC and the Field Command Post
Mobile-Router deployed in ArmoredField Unit. Secondary communications link utilized due to lost LOS of primary.
Non-preferred-pathbecomes preferred-path
Preferred-path
Non-preferred-pathIn case of communications loss of preferred-path
Mobile-Router deployed in Armored Field Unit.
INTERNET
Z
Z
ForeignAgent
HomeAgent
HQ
Hostage House
Z
Remote Command Center
INTERNET
Z
Z
ForeignAgent
HomeAgent
HQ
Hostage House
Z
Remote Command Center
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Securing Networks Constraints/Tools
Policy Security Policy Education Enforcement
Architecture Protocols
Must be done up front to be done well
Security• Security Bandwidth Utilization • Security Performance • Tunnels Tunnels Tunnels and more Tunnels• Performance Security
User turns OFF Security to make system usable!• Thus, we need more bandwidth to ensure
security.
PAYLOADHEADER
ORIGINAL PACKET
HEADER
VIRTUAL PRIVATE NETWORK
HEADER
ENCRYPTION AT THE NETWORK LAYER
HEADER
ENCRYPTION ON THE RF LINK
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Conclusions Regarding Security
Security Breaks Everything At least it sometimes feels like that. “The ultimate Denial-of-Service attack.” – D.S.
Need to change policy where appropriate. Need to develop good architectures that
consider how the wireless systems and protocols operate.
If you cannot change policy or architecture, then you must change the protocol.
Possible solutions that should be investigated: Dynamic, Protocol aware firewalls and proxies.
Possibly incorporated with Authentication and Authorization.
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Satellites and Their Competition
The Cost of Connectivity
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RF Technologies (Mobile) Globalstar (L-Band)
Globalstar MCM-8 (Client/Server) Seatel MCM-3 (Client/Server) Qualcomm MDSS-16
Boeing Connex (Ku-Band) INMARSAT Swift 64 TrackNet™ 2.0 (Ku-Band) G2.5/G3/G4
General Packet Radio Service (GPRS) – 56 kbps 1xRTT – 110 kbps
WiFi (802.11) VHF
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Satellites vs. The World Advantages
Broadcast / Multicast
Large Coverage Area
Physical Security Surveillance Remote Sensing Navigation
(Supplemented by Governments and Defense Agencies)
Disadvantage Cost to deploy Cost of Service Time to deploy Landing Rights
(politics) Bandwidth and
Frequency reuse Point-to-Point Costs Incremental
deployment may be difficult
High Link budgets Link Delay
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Cost of Connectivity (Examples)
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Deployment issues (mobile) Equipment Costs Service Cost Network Peculiarities
Network Address Translators Performance Enhancing Proxies Security Mechanisms
Packet Filtering Connection Mechanisms
Smart Card Authentication MAC and/or Static Key (manual login is unacceptable)
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Verizon Wireless Coverage
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T-Mobile Coverage
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Cingular Wireless Coverage
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GSM Coverage - TerrestrialBased on Particular Service Providers
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Satellite Coverage
Globalstar
From SaVi
INMARSAT
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Typical Ku-Band Coverage
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Applications, Requirements and Costs
128 kbps550 msec RTT
11 Mbps~50 msec RTT
Refernece: Ryu MIURA and Masayuki OOD: “R&D Program on Telecom and Broadcasting System Using High Altitude Platform Stations,” Journal of the Communications Research Laboratory Vol.48 No.4 2001
Stratospheric Platforms – These Are Coming Soon –
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High Altitude Airships (Platforms)
- Coming Soon - 500 feet long, 160
feet in diameter Volume of 5.2 million
cubic feet, about 25 times larger than the blimps seen at athletic events.
21.33 km (70,000 feet) elevation
Payload 1814 kilograms (4000 pounds)
10 kWatts power
www.lockheedmartin.com/akron/protech/aeroweb/aerostat/haa.htm
The Missile Defense Agency today (Sept 29.2003) awarded Lockheed Martin (NYSE: LMT - News) a $40 million design and risk reduction contract as the next phase of the advanced technology concept demonstration to deliver a high altitude airship (HAA) prototype in 2006
www.elec.york.ac.uk/comms/presentations/HAPsmainpres2000/HAPSmainpres.pdf
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Comments Relative to Mobile Networking Fixed Flat-Rate pricing or die
Price per bit or connect time Not manageable Impossible to budget
Voice, Video and Data are all just bits Cost of satellite equipment and services
justifies: Development of new technologies (e.g. Ad
Hoc Networks, High Altitude Airships and Stratospheric Platforms)
Deployment of new infrastructure
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Papers and Presentations
http://roland.grc.nasa.gov/~ivancic/papers_presentations/papers.html
orhttp://roland.grc.nasa.gov/~ivancic/
and pick “Papers and Presentations”