Transcript Powerpoint - Syzygy Engineering

Internet Trends
and the
Cost of Connectivity
1st BroadSky Workshop, Lacco Ameno, Italy
November 6, 2003
Will Ivancic – [email protected]
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NASA Glenn’s Space
Communications Program
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Experimental Satellites (70s – early 90s)
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Maintain US preeminence in satellite communication
Focused on Commercial Communications Satellites
Space Communications (mid 90s +)
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NASA Mission Focused
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Earth Science
Computer Information and Communications Technology (CICT)
Human Exploration and Development of Space
Aeronautics (2000 +)
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Capacity (Air Traffic Management)
Safety (Weather and Security)
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Aeronautics
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Communications, Navigation, and Surveillance (Low Data-Rate
Requirements)
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Delivery via VHF and/or Satellite
Command and Control requires a reliable transport protocol
Current protocols
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Weather (Low Data-Rate Requirements)
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Aircraft Communications Addressing and Reporting System (ACARS)
Aeronautical Telecommunication Network (ATN)
Moving Toward IPv6 (commercial standards)
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)
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Entertainment
Maintenance
Video Surveillance
Black Box Data
eBusiness (Records, manuals, maps, etc…)
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Transmission Control Protocol (TCP)
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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)
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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
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Bandwidth-Delay Product
Congestion
Errors
File Size
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Round Trip Time (RTT) Delay
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US to Japan Terrestrial
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GEO Satellite
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Negligible (Network Delay Dominates)
G2 / G3 Cellular
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550 msec (Theory)
Real Systems 0.8 - 1.5 sec
802.11 Wireless Ethernet
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20 – 100 msec
~1 Second using General Packet Radio Services (GPRS) from
T-Mobile
LEO
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~1 – 2.5 Seconds (Using Globalstar)
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Performance Enhancing Proxies (PEPs)
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Middleware deployed to help TCP performance
over links with large bandwidth-delay products
Attempt to optimize control loops
Often breaks end-to-end architecture
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If so, breaks end-to-end reliability (at lease at the
transport layer)
Difficulty working with Security (IPSec, Virtual
Private Networks)
PEPs
Internet
Internet
Control Loop 1
Control Loop 2
End-to-End Control Loop
Control Loop 3
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Reliable Transport Protocol
Developments
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TCP Swift Start
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TCP Westwood
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Attacks Additive Increase, Multiplicative Decrease (AIMD)
problem
Cumulative Explicit Transport Error Notification
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Improves Slow Start Performance
Attacks Additive Increase, Multiplicative Decrease (AIMD)
problem
Stream Control Transport Protocol (SCTP)
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New Reliable Transport Protocol
Incorporates many proposed improvements to TCP
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Byte Counting
Selective Acknowledgements
Non-Blocking of multiple streams
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Internet Trends
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Inexpensive Broadband Connectivity
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Always On Connectivity
Peer-to-Peer networking
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Maintain connections when crossing networks
IPv6
Security
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Web replaces paper forms (e.g. eNASA, eCoast Guard)
Network Centric Warfare
Mobile Networking
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Symmetric Links (no longer highly asymmetric)
Conversation may be initiated from outside your network!
eBusiness
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Cable Modem, DSL, WiFi, G2.5/G3/G4
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?
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Mobile IP is a routing protocol that enables IP
nodes (hosts and routers) using either IPv4
or IPv6 to seamlessly “roam" among IP
subnetworks.
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Supports transparency above the IP layer,
including the maintenance of
active TCP connections and UDP port bindings.
Link Independent
Supports Multi-Homing (connections to more than
one route and/or media type)
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Mobile Router uses
Time
Ethernet
Ethernet
FA
FA
PortB
FA
Port A
NOC HA
Carnival Cruise
Military Applications
AWACS
Tactical data forwarded from
surveillance satellites to the BGCC.
Home-Agent
deployed in
BGCC
Communications link
between BGCC and the
Field Command Post
Battle Group Command Center (BGCC)
Foreign-Agent
deployed in UAV
Intelligence Control
Center
Non-preferred-path
becomes preferred-path
UAV
Non-preferred-path
In case of communications
loss of preferred-path
Preferred-path
Mobile-Router deployed in Armored
Field Unit. Secondary communications
link utilized due to lost LOS of primary.
Mobile-Router deployed in
Armored Field Unit.
Foreign-Agent deployed in
Tracked Command Post Carrier.
Unit deployed in vicinity of the
battlefield.
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Hostage House
Z
INTERNET
Foreign
Agent
HQ
Z
Home
Agent
Z
Remote Command Center
Hostage House
Z
INTERNET
Foreign
Agent
HQ
Z
Home
Agent
Z
Remote Command Center
Securing Networks
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Constraints/Tools
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Policy
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Security Policy
Education
Enforcement
Architecture
Protocols
Must be done up front to be done well
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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.
ENCRYPTION ON THE RF LINK
ENCRYPTION AT THE NETWORK LAYER
VIRTUAL PRIVATE NETWORK
ORIGINAL PACKET
HEADER
HEADER
HEADER
HEADER
PAYLOAD
Conclusions Regarding Security
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Security Breaks Everything 
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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:
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Dynamic, Protocol aware firewalls and proxies.
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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)
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Globalstar (L-Band)
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Boeing Connex (Ku-Band)
INMARSAT Swift 64
TrackNet™ 2.0 (Ku-Band)
G2.5/G3/G4
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Globalstar MCM-8 (Client/Server)
Seatel MCM-3 (Client/Server)
Qualcomm MDSS-16
General Packet Radio Service (GPRS) – 56 kbps
1xRTT – 110 kbps
WiFi (802.11)
VHF
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Satellites vs. The World
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Advantages
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Broadcast / Multicast
Large Coverage Area
Physical Security
Surveillance
Remote Sensing
Navigation
(Supplemented by
Governments and
Defense Agencies)
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Disadvantage
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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)
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Equipment Costs
Service Cost
Network Peculiarities
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Network Address Translators
Performance Enhancing Proxies
Security Mechanisms
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Packet Filtering
Connection Mechanisms
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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 - Terrestrial
Based on Particular Service Providers
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Satellite Coverage
Globalstar
INMARSAT
From SaVi
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Typical Ku-Band Coverage
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Applications, Requirements and Costs
128 kbps
550 msec RTT
11 Mbps
~50 msec RTT
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Stratospheric Platforms
– These Are Coming Soon –
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
High Altitude Airships (Platforms)
- Coming Soon 
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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
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www.elec.york.ac.uk/comms/presentations/HAPsmainpres2000/HAPSmainpres.pdf
Comments Relative to Mobile
Networking
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Fixed Flat-Rate pricing or die
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Price per bit or connect time
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Not manageable
Impossible to budget
Voice, Video and Data are all just bits
Cost of satellite equipment and services
justifies:
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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
or
http://roland.grc.nasa.gov/~ivancic/
and pick
“Papers and Presentations”
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