18-05-2010, 01:18 PM
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SKY X TECHONOLOGY
Contents
INTRODUCTION
The internet protocols are not optimized for satellite conditions and consequently the throughput over the satellite networks is restricted to only a fraction of available bandwidth.
The Sky X systems replaces TCP over satellite page link with a protocol optimized for the long latency, high loss and asymmetric bandwidth conditions of the typical satellite communication.
Adding the Sky X system to a satellite network allows users to take full advantage of the available bandwidth.
The Sky X Client and the Sky X Server enhance the performance of data transmissions over satellites directly to end user PCâ„¢s, thereby increasing Web performance by 3 times or more and file transfer speeds by 10 to 100 times.
Sky X System
Sky X products increase the performance of IP over satellite through a combination of protocol connection-splitting, data compression, and Web pre-fetching, while remaining entirely transparent to end users.
The Sky X works by transparently replacing TCP connections from the client and converting the data to Xpress Transport protocol (XTP) for the hop over the satellite page link which is the protocol optimized for satellite conditions.
Gateway Operations..
The Sky X gateway works by intercepting the TCP connection from the client and converting the data to the Xpress Transport Protocol (XTP) for transmission over the satellite.
The Sky X gateway on the opposite side of the satellite page link translates the data back to TCP for communication with the server.
This architecture offers vastly improved performance while remaining entirely transparent to the end user.
The Sky X gateway splits the single TCP connection into three separate components.
A TCP connection on the remote side between the client and Sky X gateway, an XTP connection involving Sky X protocol over the satellite between the two Sky X gateways and a TCP connection between the opposite Sky X gateway and server.
XTP
XTP is a reliable, transport-layer protocol specifically designed to operate efficiently over high-speed networks and offers a level of performance not possible with TCP on long latency, high loss satellite links.
Working
The two Sky X gateways pass control data between each other, allowing the Sky X gateway on the opposite side of the satellite to appear to be the original source or destination device. This architecture maintains full TCP reliability and end-to-end flow control.
Client-server operations
The Sky X Client / Server increases the throughput and efficiency of network access over satellites by transparently replacing TCP with the Xpress Transport Protocol (XTP) for the satellite segment of the connection.
The sky X client/server system enhances the performance of the internet and private network access over satellite links.
The sky X client software installed on the PCâ„¢s of the end user, works in conjunction with a sky X server hardware unit located at the network hub.
Operations of client-server¦
The Sky X Client, installed on Microsoft Windows-based computers, transparently intercepts TCP connections from applications running on the PC and transmits the data over the satellite page link using XTP.
The Sky X Server, installed at the hub of the satellite network, establishes a new TCP connection for communication with any device on the local network or over the Internet.
The Sky X Server is available in two models namely the SS10 and SS45. The SS10 provides Sky X enhancement for links of up to 10 Mbps while the SS45 provides Sky X enhancement for links of up to 45 Mbps.
Sky X Multicast Fan out
Computer networking traditionally relies on unicast data transfers which establish point-to-point connections between devices.
In situations where the same data is transferred to multiple users, the server must send a copy of the file to each recipient independently. This process is both time consuming and wastes much of the bandwidth resources.
In contrast, multicast technology makes it possible for multiple recipients to receive a single data stream.
The Sky X multicast fanout, an integral component of the Sky X gateway, transparently converts TCP unicast connections into reliable multicast transfers.
Through the use of common TCP based applications such as FTP, the Sky X gateway can deliver a file to every remote location across a wide area network with only a single multicast transfer.
By combining this reliable multicast transmission technology with a transparent fanout functionality which allows any TCP connection to be converted into a multicast transfer.
Sky X multicast fanout functionality is ideal for file transfers, cache replication, video file distribution, content delivery networks, database replication, and any other distribution of data or files to multiple users over a satellite page link or other wide area network.
Performance
Without performance enhancement, a default window size of 8 KB limits TCP throughput to less than 100 Kbps over satellite. As the graph on the left illustrates, even on server operating systems using a 32 KB window, TCP is only able to reach a through-put of 440 Kbps.
Sky X gateway overcomes this limitation, taking full advantage of the available bandwidth regardless of the window size of the client or server. For compressible data, Sky X can provide throughput rates far greater than the page link bandwidth.
Round-Trip Delay vs. Throughput
The Sky X gateway system removes the dependency of TCP on the round-trip time of the link.
The figure below shows the measured throughput on an error-free, 10 Mbps link. These results illustrate that TCP throughput drops rapidly as the round-trip time increases.
In contrast, Sky X is able to maintain full usage of the page link regardless of the round-trip time. For compressible text, Sky X consistently delivers throughput rates greater than the actual bandwidth.
Bit Error Rate vs. Throughput
The Sky X system overcomes the high sensitivity of TCP to the bit error rate of the link.
The graph given below shows the throughput as a function of the bit error rate for a 10 Mbps satellite page link using a 1 MB TCP window.
Even at low error rates, TCP is able to deliver only 1.5 Mbps.
Sky X fully saturates the page link at low error rates and even at an error rate of 1×10-5, achieves 5.1 Mbps.
Applications
The Sky X gateway combines protocol, application and system level enhancements to provide maximum throughput for satellite networks.
The Sky X Protocol utilizes a highly efficient selective retransmission algorithm for the acknowledgment of data. Because there is only a single path over the satellite with no intermediate routing.
Sky X products include HTTP specific optimizations to further accelerate web downloads.
Packeteer SKY X
Packeteer Introduces New SkyX Accelerators for Improved TCP-Based Application Performance.
New SkyX Accelerators Support Expanded Range of Link Speeds.
The introduction of two new SkyX Accelerator models based on new hardware platforms that provide substantially improved scalability to support future features and functional enhancements.
Packeteer's SkyX Accelerators improve TCP-based application performance including SAP, FTP file transfers, e-mail and Web access.
SKY X accelerator
When TCP protocol design limitations, high latency and lost packets threaten application connection speed, SkyX Accelerator ramps flow, fully utilizes links and keeps data moving along.
Accelerate file trasfers, large and small speed XML.
Optimize application performance over high-latency and satellite links.
Increase page link utilization on fat WAN Links.
Maximize bandwidth utilization and ROI.
Minimize retransmission and recover more quickly from errors.
Conclusion
The sky X gateway is the leading solution for overcoming the limitations of TCP/IP over satellite. ISPâ„¢s, corporations, governments, and military organizations around the world rely on sky X gateway to enhance the performance of their satellite networks.
Testing by independent third parties including INTELSAT and NASA confirms that the sky X Gateway dramatically improves performance for the internet and private access over satellite networks.
The world is reducing to a global village by the use of satellite communication and so the improvement in the rate of information interchange through satellite is a must and thus sky X technology becomes unavoidable.
SKY X TECHONOLOGY
Contents
INTRODUCTION
The internet protocols are not optimized for satellite conditions and consequently the throughput over the satellite networks is restricted to only a fraction of available bandwidth.
The Sky X systems replaces TCP over satellite page link with a protocol optimized for the long latency, high loss and asymmetric bandwidth conditions of the typical satellite communication.
Adding the Sky X system to a satellite network allows users to take full advantage of the available bandwidth.
The Sky X Client and the Sky X Server enhance the performance of data transmissions over satellites directly to end user PCâ„¢s, thereby increasing Web performance by 3 times or more and file transfer speeds by 10 to 100 times.
Sky X System
Sky X products increase the performance of IP over satellite through a combination of protocol connection-splitting, data compression, and Web pre-fetching, while remaining entirely transparent to end users.
The Sky X works by transparently replacing TCP connections from the client and converting the data to Xpress Transport protocol (XTP) for the hop over the satellite page link which is the protocol optimized for satellite conditions.
Gateway Operations..
The Sky X gateway works by intercepting the TCP connection from the client and converting the data to the Xpress Transport Protocol (XTP) for transmission over the satellite.
The Sky X gateway on the opposite side of the satellite page link translates the data back to TCP for communication with the server.
This architecture offers vastly improved performance while remaining entirely transparent to the end user.
The Sky X gateway splits the single TCP connection into three separate components.
A TCP connection on the remote side between the client and Sky X gateway, an XTP connection involving Sky X protocol over the satellite between the two Sky X gateways and a TCP connection between the opposite Sky X gateway and server.
XTP
XTP is a reliable, transport-layer protocol specifically designed to operate efficiently over high-speed networks and offers a level of performance not possible with TCP on long latency, high loss satellite links.
Working
The two Sky X gateways pass control data between each other, allowing the Sky X gateway on the opposite side of the satellite to appear to be the original source or destination device. This architecture maintains full TCP reliability and end-to-end flow control.
Client-server operations
The Sky X Client / Server increases the throughput and efficiency of network access over satellites by transparently replacing TCP with the Xpress Transport Protocol (XTP) for the satellite segment of the connection.
The sky X client/server system enhances the performance of the internet and private network access over satellite links.
The sky X client software installed on the PCâ„¢s of the end user, works in conjunction with a sky X server hardware unit located at the network hub.
Operations of client-server¦
The Sky X Client, installed on Microsoft Windows-based computers, transparently intercepts TCP connections from applications running on the PC and transmits the data over the satellite page link using XTP.
The Sky X Server, installed at the hub of the satellite network, establishes a new TCP connection for communication with any device on the local network or over the Internet.
The Sky X Server is available in two models namely the SS10 and SS45. The SS10 provides Sky X enhancement for links of up to 10 Mbps while the SS45 provides Sky X enhancement for links of up to 45 Mbps.
Sky X Multicast Fan out
Computer networking traditionally relies on unicast data transfers which establish point-to-point connections between devices.
In situations where the same data is transferred to multiple users, the server must send a copy of the file to each recipient independently. This process is both time consuming and wastes much of the bandwidth resources.
In contrast, multicast technology makes it possible for multiple recipients to receive a single data stream.
The Sky X multicast fanout, an integral component of the Sky X gateway, transparently converts TCP unicast connections into reliable multicast transfers.
Through the use of common TCP based applications such as FTP, the Sky X gateway can deliver a file to every remote location across a wide area network with only a single multicast transfer.
By combining this reliable multicast transmission technology with a transparent fanout functionality which allows any TCP connection to be converted into a multicast transfer.
Sky X multicast fanout functionality is ideal for file transfers, cache replication, video file distribution, content delivery networks, database replication, and any other distribution of data or files to multiple users over a satellite page link or other wide area network.
Performance
Without performance enhancement, a default window size of 8 KB limits TCP throughput to less than 100 Kbps over satellite. As the graph on the left illustrates, even on server operating systems using a 32 KB window, TCP is only able to reach a through-put of 440 Kbps.
Sky X gateway overcomes this limitation, taking full advantage of the available bandwidth regardless of the window size of the client or server. For compressible data, Sky X can provide throughput rates far greater than the page link bandwidth.
Round-Trip Delay vs. Throughput
The Sky X gateway system removes the dependency of TCP on the round-trip time of the link.
The figure below shows the measured throughput on an error-free, 10 Mbps link. These results illustrate that TCP throughput drops rapidly as the round-trip time increases.
In contrast, Sky X is able to maintain full usage of the page link regardless of the round-trip time. For compressible text, Sky X consistently delivers throughput rates greater than the actual bandwidth.
Bit Error Rate vs. Throughput
The Sky X system overcomes the high sensitivity of TCP to the bit error rate of the link.
The graph given below shows the throughput as a function of the bit error rate for a 10 Mbps satellite page link using a 1 MB TCP window.
Even at low error rates, TCP is able to deliver only 1.5 Mbps.
Sky X fully saturates the page link at low error rates and even at an error rate of 1×10-5, achieves 5.1 Mbps.
Applications
The Sky X gateway combines protocol, application and system level enhancements to provide maximum throughput for satellite networks.
The Sky X Protocol utilizes a highly efficient selective retransmission algorithm for the acknowledgment of data. Because there is only a single path over the satellite with no intermediate routing.
Sky X products include HTTP specific optimizations to further accelerate web downloads.
Packeteer SKY X
Packeteer Introduces New SkyX Accelerators for Improved TCP-Based Application Performance.
New SkyX Accelerators Support Expanded Range of Link Speeds.
The introduction of two new SkyX Accelerator models based on new hardware platforms that provide substantially improved scalability to support future features and functional enhancements.
Packeteer's SkyX Accelerators improve TCP-based application performance including SAP, FTP file transfers, e-mail and Web access.
SKY X accelerator
When TCP protocol design limitations, high latency and lost packets threaten application connection speed, SkyX Accelerator ramps flow, fully utilizes links and keeps data moving along.
Accelerate file trasfers, large and small speed XML.
Optimize application performance over high-latency and satellite links.
Increase page link utilization on fat WAN Links.
Maximize bandwidth utilization and ROI.
Minimize retransmission and recover more quickly from errors.
Conclusion
The sky X gateway is the leading solution for overcoming the limitations of TCP/IP over satellite. ISPâ„¢s, corporations, governments, and military organizations around the world rely on sky X gateway to enhance the performance of their satellite networks.
Testing by independent third parties including INTELSAT and NASA confirms that the sky X Gateway dramatically improves performance for the internet and private access over satellite networks.
The world is reducing to a global village by the use of satellite communication and so the improvement in the rate of information interchange through satellite is a must and thus sky X technology becomes unavoidable.
