A survey on how Sky X Technology intends to take over from its TCP counterpart in the upcoming future.

1. Sky X Technology
Soumyajit Pal
Department of Computer Science
St. Xavier’s College
Kolkata, India

2. OVERVIEW
• Satellite
• Satellite communication
• Characteristics of satellite communication
• TCP and its limitations
• Sky X Family
• XTP
• Performance of Sky X System
• Advantages of Sky X System
• Future prospects of Sky X System
• Conclusion
• References

3. Satellite

4. Satellite Communication

5. Characteristics of satellite communication
• Long latency.
• Asymmetric bandwidth.
• High bit error rate.
• Back channel bandwidth much smaller than
forward channel.

6. TCP and its limitations
• Transmission Control Protocol (TCP).
• Functions in the transport layer of TCP/IP
protocol suite.
• Connection-oriented and reliable.
• Greatly used for terrestrial communication.
• Incapable to handle harsh conditions
associated with satellite transmission.

7. TCP and its limitations (cont.)
• Window Size – Sliding window mechanism to limit data
transferred. If window becomes full sender stops and
waits for new ACK. Not suited for satellite
communication: distance.
• Congestion Avoidance – Assumes all data loss is due to
congestion and reduces rate of data transfer.
Misinterprets satellite scenario typically characterized
by long round-trip time and bit errors.
• Data ACK Scheme – TCP uses ACK scheme to provide
high reliability. Again ill-suited for satellite links

8. Sky X Family
• Works particularly well in satellite conditions.
• Provides data compression and web specific
enhancements.
• Provides maximum performance.
• Throughput exceeds bandwidth for
compressed data.
• Consists of Sky X Gateway and Sky X
Client/Server.

9. Sky X Gateway
• Transparently replaces TCP connections from
client and converts data to Xpress Transport
Protocol for transmission over satellite.
• Sky X Gateway on opposite side of satellite
link translates data back to TCP for
communication with server.
• Also known as TCP-PEP.
• Splits single TCP connection into three
separate components.

10. Sky X Client/Server
• Similar to Sky X Gateway.
• Only difference: Sky X Client software installed
separately on each client.
• Connections from client intercepted and send
over satellite using XTP.
• Sky X server establishes a TCP connection with
destination server.
• Transparency replacing.
• Enhances performance of Internet and private
networks over satellite links.

11. Xpress Transport Protocol (XTP)
• Reliable.
• Real time.
• Lightweight.
• Developed by a group of researchers at
Protocol Engines Incorporated (PEI).
• Specially designed for high-speed, reliable and
interconnected networks like satellite.

12. XTP (cont.)
• Efficient ACK Algorithm.
• Flow Control.
• Dynamic Window Sizing.
• Rate Control.
• Error Control.
• Data Compression.

13. Performance of Sky X
• Performance depends on the following
factors:
• Bandwidth.
• Delay.
• Asymmetry.
• Bit error rate.
• Number of simultaneous connections.
• Compressibility of data.

14. Advantages of Sky X
• Makes satellite communication come alive.
• Transparency enhancement.
• Web performance go up by 3 times or more.
• File transfer speeds go up by 10 to 100 times.
• Maximizes throughput such that it exceeds
bandwidth.
• Example: For a bandwidth of 10 Mbps for a
satellite network Sky X provides throughput of
5.8 Mbps for uncompressed data and 15.1 Mbps
for compressed data.

15. Future Prospects
• SCPS redefines the Internet protocols for
operation over stressed communication links.
• XipLink is an independent and high
performance implementation of SCPS.
• Will be replacing Sky X for satellite
communications.
• Aims for even greater level of performance.

16. Conclusion
• Tested successfully.
• World is reducing to a global village.
• Long distance communication is imperative.
• Improvement in rate of information exchange.
• Sky X Technology is unavoidable.

17. References
• [1] Robert M. Sanders and Alfred C. Weaver, The Xpress Transport Protocol (XTP) - A tutorial,
Computer Networks Laboratory Department of Computer Science Thornton Hill University of
Virginia.
• [2] Craig Partridge and Timothy J. Shepard, TCP/IP Performance over satellite links, BBN
Technologies
• [3] Prof. S. Ghosh, Lecture No. # 31 TCP, Centre for Educational Technology, Indian Institute of
Technology Kharagpur, National Program on Technology Enhanced Learning (NPTEL), Computer
Networks.
• [4] Prof. S. Ghosh, Lecture No. # 18 Satellite Communication, Centre for Educational Technology,
Indian Institute of Technology Kharagpur, National Program on Technology Enhanced Learning
(NPTE), Computer Networks.
• [5] https://www.petri.com/forums/forum/networking/general-networking/46348-ip-traffic-vs-non-
ip-traffic, IP Traffic vs non-IP Traffic - Petri IT Knowledgebase Forums
• [6] http://www.rfwireless-world.com/Terminology/satellite-based-communication-vs-terrestrial-
based-communication.html, Satellite based communication vs terrestrial based communication |
difference between Satellite based communication and terrestrial based communication
• [7] http://www.spacedaily.com/news/internet-03t.html, SkyX Gateway Increases Web Satellite
Download Speeds Up to 8 Times
• [8] http://www.cnet.com/products/mentat-skyx-gateway-xr10-gateway/, Mentat SkyX Gateway
XR10 - gateway Overview - CNET

18. References (cont.)
• [9] http://it.med.miami.edu/x198.xml, Public vs. private networks - Information Technology - Miller School of
Medicine at the University of Miami
• [10] http://www.slideshare.net/search/slideshow?searchfrom=header&q=Sky+X+Technology, 'Sky X Technology'
on SlideShare
• [11] http://www.slideshare.net/kedar1993/sky-x-technology-43938904?qid=0656ea4c-cc2f-4c83-bd46-
9a3ed8735878&v=qf1&b=&from_search=7, Sky x technology
• [12] http://s3.amazonaws.com/ppt-download/skyxtechnology-150127042126-conversion-gate02.pptx?response-
content-
disposition=attachment&Signature=%2FhlexpxIY%2FpN%2FqP9t0XYt6h46RE%3D&Expires=1446528616&AWSAcce
ssKeyId=AKIAIA7QTBOH2LDUZRTQ, skyxtechnology-150127042126-conversion-gate02.pptx
• [13] http://www.slideshare.net/ankurroyaldude/sky-x-ppt-ankur?qid=0656ea4c-cc2f-4c83-bd46-
9a3ed8735878&v=qf1&b=&from_search=8, sky x ppt ankur
• [14] http://www.slideshare.net/ManojDatt1/sky-x-tech-ppt-by-manoj-datt?qid=0656ea4c-cc2f-4c83-bd46-
9a3ed8735878&v=qf1&b=&from_search=9, Sky X Tech PPT by Manoj Datt
• [15] http://s3.amazonaws.com/ppt-download/a1522ef3-3da3-4201-a769-70efcb2596e1-150623120620-lva1-
app6891.pptx?response-content-
disposition=attachment&Signature=409lmcoBmzgayTK0vydpJGuj38g%3D&Expires=1446528701&AWSAccessKeyId
=AKIAIA7QTBOH2LDUZRTQ, a1522ef3-3da3-4201-a769-70efcb2596e1-150623120620-lva1-app6891.pptx
• [16] http://s3.amazonaws.com/ppt-download/presentation1-150219215710-conversion-gate01.pptx?response-
content-
disposition=attachment&Signature=LawiqRmWOoNxRwZ%2BqYzGrpYSLjs%3D&Expires=1446528730&AWSAccess
KeyId=AKIAIA7QTBOH2LDUZRTQ, presentation1-150219215710-conversion-gate01.pptx

19. References (cont.)
• [17] http://s3.amazonaws.com/ppt-download/spyxtchnology-120120074244-
phpapp02.ppt?response-content-
disposition=attachment&Signature=SeR676qo1ztIjsHZgwRgamS8z3M%3D&Expires
=1446528752&AWSAccessKeyId=AKIAIA7QTBOH2LDUZRTQ, skyxtchnology-
120120074244-phpapp02.ppt
• [18] https://en.wikipedia.org/wiki/Performance-enhancing_proxy, Performance-
enhancing proxy - Wikipedia, the free encyclopedia
• [19] https://en.wikipedia.org/wiki/Xpress_Transport_Protocol, Xpress Transport
Protocol - Wikipedia, the free encyclopedia
• [20] https://en.wikipedia.org/wiki/Category:Transport_layer_protocols,
Category:Transport layer protocols - Wikipedia, the free encyclopedia
• [21] https:// en.m.wikipedia.org/wiki/Protocol-spoofing, Protocol Spoofing
• [22] http:// www.wickedbandwidth.com/difference_symmetrical_asymmetrical,
Difference between symmetrical and asymmetrical bandwidth
• [23] http://www.xiplink.com, XipLink Technology
• [24] https://en.m.wikipedia.org/wiki/Satellite_internet_access, Satellite internet
access

20. Questions!