A Study On The Sky X Devices

In today’s worlds Connectivity is the most important thing. No matter where ever we are we need to keep ourselves connected with the world to keep ourselves updated. The world around us is changing at a rapid pace so if we don’t keep up with it we would be left behind. One of the prime way by which we do this is internet. But there are places where Internet is not available. There are few places where due to terrestrial location or other reasons the internet availability is not possible or it’s prohibited.

In today’s world we feel like sharing whatever we can on the network, we share a lot of data on the network. We keep uploading the Videos on Youtube. We keep on adding our photo on the networking websites. Day by day our need for the bandwidth is increasing as our need to share and upload the data keeps on increasing.

Here comes an option for this also it’s the communication using the satellites. The Geo-stationary satellite orbiting at an altitude of 36,000 kms can be used for this. Satellites can be used to carry our data traffic and they could be used to communicate with each other. But the problem with it was that the prevalent TCP protocol at that time did not have enough of technology advances to overcome the disadvantages of satellite communication as compared to its advantages.

So the “SKY-x technology “was introduced, it provided a secure and fast way to transfer data through satellite. It was totally transparent to the users. In place of tcp protocol it used a new XTP protocol (Xpress Transport Protocol) .This new Protocol is optimize for the data transfer over Satellite.

Problem with TCP:

The data transfer using satellite is facing various problems like large latency rate and high Bit error rate with the Asymmetric design of the bandwidth of all satellite. Satellite is one of the best options in the upcoming days to communicate and transfer data. But there did not exist proper standards or Protocol for the transfer of the data. The currently used TCP Protocol was not optimized for the transfer of data over Satellite, due to which the High bandwidth provided by the Satellite mostly goes unused. This also reduces the throughput of the satellite transmission. So we were not able to fully utilize the benefits provided by the Satellite transmission.

Where as the Satellite transmission was more prone to bit error caused due to the environmental changes. The TCP Protocol was designed so that they can give high performance and large throughput over local area network.TCP protocol had various feature for LPV6 which were specialized for the Optical fiber network. So network setup of Optical cables and using the TCP protocol were far more reliable and cheaper than transmission using TCP protocol over satellite. All the benefits which are incurred over the cable network by TCP Protocol are lost on the satellite transmission.

TCP had a congestion avoidance algorithm/mechanism which were not suited for satellite transmission because satellite transmission had a long round trip. This long round trip was misinterpreted by the TCP as congestion and hence it reduces the transmission rate. This resulted in the wastage of the bandwidth provided by the Satellite transmission. Hence the Congestion avoidance algorithm used by the TCP is also a big problem in the Satellite transmission.

The WINDOW SIZE Problem:

The TCP protocol utilizes a sliding window mechanism to limit the total amount of data to be transfer over the network. When the window become full, the sender stops sending the data anymore until it receives the acknowledgment signal from the recevier.As the back channel speed is less on satellite using tcp protocol its very difficult to transfer data on satellite, So to avoid this TCP statically fix the size of window to 100 kb over the T1 satellite, which limits the total amount of bandwidth which we can use as compared to total provided by the satellite. Moreover many of the operating system uses a window size of 8 Kb which only provides us with a speed of 128 kbps per connection, which is very less as compared to bandwidth available over satellite. Thus window sizing mechanics reduces the transfer of the data over the Satellite.

While the SK-x technology dose not use a fix window size of 8 Kb it uses the performance enhanced size of the window thus allowing us to fully utilize the bandwidth provided by the Satellite & for the data which can be compressed SKY-x technology provides a better throughput rate than the simple cable network. Thus the SKY-x technology is much better than the TCP Protocol for the transfer of data over the satellite.

SKY- x Technology:

The SKY-x technology was developed by one of the worlds leaders in TCP/IP Protocol developer Mentat.The SKY-x technology Products replace the TCP protocol product to transfer data over Satellite. These Products are transparent to Users they behave the same way as the TCP Protocol product and they provide more security and Less Latency time while giving high throughput over satellite. It consists of SKY-x Gateway, SKY-x Client/Server, SKY-x OEM Products. The SKY-x gateway works in the same way as the TCP Gateway except that the Sky-x gateway intercepts the TCP signal and helps to convert it to the SKY-x protocol so that it can be used to transfer over the satellite. The SKY-x client are the same except that they need to be installed on the pc’s of the local user to help them to connect using satellite.

The SKY-x technology & Protocol replaces the TCP Protocol used on Optical Fiber for the use on the satellite. Adding the SKY-x products into the network helps the user to efficiently use the full bandwidth provided by the satellite. The SKY-x products enhances the performance of the network transparently with out needing to change any thing over the client side or the server side. The SKY-x product increases the overall performance by thrice, while increases the files transfer by 10 to 100 times over the satellite. This product are enhanced version of the otherwise known TCP Performance enhancing (TCPPEP) Or the Satellite spoofer.

The XTP protocol used was developed by the XTP forum a non profit organization. The SKY-x products divide the normal TCP connection into three different components:

1. The connection between the TCP client and the SKY-x gateway on the remote side of the network.

2. The Connection between two SKY-x gateway involving XTP protocol for the transfer of the data over the Satellite.

3. The Connection between the SKY-x Gateway and the TCP server on the other side of the network.

Unicast versus Multicast:

The fiber optic network used the unicast data transfer to send the data to all the clients it used to send the same copy of data to all the clients which a bit time consuming and waste a lot of bandwidth of the network. While the Unicast was not good for the satellite network. But the only multicast protocol available was UDP based. This UDP based protocol did not involve any method to detect the error in data transfer and to check the re-transmission of the data over the network. It even does not provide any mechanism to re-sequences the data packets sent over the network.

This problem was overcome by the SKY-x multicast. It provides a reliable and secure way to multicast the data over the satellite. It provides fast efficient, reliable multicast file transfer. Any data that is lost or corrupted during the transmission is re-transmitted, providing transfer reliability & rendering the special FEC software as a unnecessary thing. The SKY-x multicast fan out is an important part of the SKY-x Gateway. It transparently converts the TCP unicast data to the SKY-x multicast data. The SKY-x gateway can transfer the file to every remote location with just one multicast. As the SKY-x multicast is transparent to the user any device can transfer the data using the Multicast no matter whatever operating system it has without needing any special software.

Below is a graph showing comparison between Unicast traffic and Multicast traffic:

As shown in the graph Unicast transmission increases the traffic of the network considerably, whereas using multicast for the same no of users the traffic is 18th of the Unicast transmission. Thus the SKY-x technology also reduces the traffic over the high bandwidth Satellite Network.

Thus SKY-x technology has overcome each and every Limitation of the TCP protocol & hence providing us with an efficient way to connect using the Satellite.

SPEED – TCP versus SKY-x:

The new technology used in the Sky-x products increases the performance as well as the speed of the network. The SKY-x products use a Fast start feature which enables it to establish new connection at a very fast speed. The HTTP Benchmark by the WEB Stone shows that for an 8 Mbps line having 50 simultaneous connections using a SKY-x gateway has an average response time of 0.7 to 1.1 sec which is much lowered as compared to the 3 sec time on a network using TCP protocol.

Increased Throughput:

The Sky-x Technology provides a high bandwidth even at a high bit error rate. It does so by compressing the data transmitted over the network. For a 10 Mbps satellite the TCP protocol is able to provide a small bandwidth of 1.5 Mbps while at an error rate of 1* 10-5 its bandwidth drops to as low as 0.03 Mbps. While on the other hand even at the above mentioned error rate the SKY-x products maintains a bandwidth of 5.8 Mbps when the data is not compressible, if the data is compressible it maintains a bandwidth of 15.1 Mbps.

THE SKY-x Architecture:

The SKY-x products or network have a SKY-x Gateway installed into the system. This gateway provided by the SKY-x helps to make the network transparent to the user, it transparently intercepts the TCP protocol transmitted by the user and convert it into the XTP (Xpress Transport Protocol) which is optimized for the Satellite transmission. Then on the other side it converts back the XTP protocol into the TCP protocol for the Server. So the client and the Server side in the Network remain unaware to all this translation. It requires no special change to be made on the part of the client or the Server in the Network, so all the applications & the Program which were used previously keeps functioning on this network also.

The XTP protocol also supports the TCP congestion avoidance algorithm to keep the terrestrial network stable and protected. The two Sky-x Gateway pass the data between each other as if there doesn’t exists any intermediate link between client and the server.

XTP protocol also provides a functionality called as Web pre-fetching. The Web Pre-fetch is used to fetch all the embedded objects in a web page whenever a client sends a request for even a simple html page. Then these embedded objects are made visible to the client as and when it is requested by the client thus avoiding the fetch time required for fetching it from the satellite.

Thus the XTP protocol not only provides the security & stability on the satellite network but it also considerably increases the speed of data transfer by using the Web Pre-fetch.

XTP also provides an Accelerator which helps in speeding up the network traffic. It accelerates the XML and HTTP sessions, database synchronization as well as the transfer of the file Large or small between the client and the Server. Thus it helps in providing a better response time and throughput of the network. It also helps in speeding up the Database backups. It minimizes the re-transmission of data required due to error in it or due to the loss of data. Thus it also helps in the use of Satellite as a communication medium.

SKY-x Products:

Mentat was the first company to build a product having the sky-x technology. Mentat is leader in developing the products based on the TCP/IP protocol. Renowned Companies like Apple, IBM, Motorola, and Sony depend on the TCP/IP network software provided by Mentat. It launched various product named

Mentat SKY-x XR10 Gateway.

Mentat SKY-x XH45 Gateway.

Mentat SKY-x XH155 Gateway.

These products built by Mentat had the in built Accelerator to speed up the network traffic.

The XR10 is designed to be used for the satellite which provides a link of 10 Mbps. Or it could also be used in combination with the other Mentat products like the XH45 which supports higher bandwidth links.

The XH45 is designed for the satellite providing the link of 45 Mbps or it can also be used as a hub in a network having XR10 products.

In the Same way Mentat also provides the SKY-x servers as SS10 & SS45.

The SKY-x SS10 server is used in the network having 10 Mbps links.

While the SKY-x SS45 server is used in the network having the 45 Mbps links.

Packeteer Mobiliti Technology:

Packeteer is the Global Leader in Wan Application Optimization. In Today’s World the users should be able to work from wherever there business demands. On the other hand the Companies should also provide their workers with the facility like LAN no matter wherever they are or they would be at a risk to lose many chances to carry out their business successfully. Packeteer came forward with a solution to this by integrating the SKY-x technology into its Mobility software. So the user can access the LAN from the remote location using there Desktops and Laptops.

This Mobiliti software supports TCP file transfer & automatic backup. It cache’s or saves the recently used document on the client side so as that the user can access them whenever needed even if the server is not available. This software is available in various languages like German, French, Chinese and Japanese. It also automatically configures the my document folder & also provides and option to choose the location to store the recently used file by the user.

Conclusion:

Thus the new SKY-x technology is better than the TCP Protocol for Satellite transmission. The Sky-x Technology provides a large bandwidth as well as a fast data transfer on the satellite network. It has removed all the limitations which existed in the use of TCP for satellite transmission. Thus the SKY-x technology has opened a new horizon in the way we used to communicate with each other. Now we can use the Satellite as the medium of communication and remain connected with each other even at the most remote places on the earth.

And this new SKY-x Technology also comes as a savior to us for our daily increasing bandwidth requirements. It provides a large bandwidth to transfer data on the network. Thus now we can connect to more places and also share more Data on the network.