Transcript Document
Very Small Aperture Terminal V-SAT Presented By Kumar Anand Singh Reg No. 04-243 Department of Electronics & Telecommunication Engineering Outline • • • • • • • Introduction Network - VSAT Equipments Installed Server Setup How Managing Network Challenges and Solution Summary VSAT • VSAT stands for "Very Small Aperture Terminal" and refers to receive/transmit terminals installed at dispersed sites connecting to a central hub via satellite using small diameter antenna dishes (0.6 to 3.8 meter). • VSAT networks are now viewed as the most flexible platform in the communications marketplace, typically allowing remote locations to communicate with other sites or a centralized computing facility. SCPC is used for economical distribution of broadcast data as well as for full-duplex or two-way data or video communications. • In a SCPC system, user data is transmitted to the satellite continuously on a single satellite carrier. The satellite signal is received at a single location, in the case of a point-to-point system, or at many locations in a Star Hub Configuration. INTRODUCTION OF VSAT NETWORKS • VSAT is kind of fixed satellite service • VSAT = Very Small Aperture Terminal • VSATs are usually part of intelligent network • Antenna size is typically 0.7 m to 3.7 m , radio output is typically 2 – 20 W VSAT Communication TYPES OF VSAT NETWORKS . Packet Switched Networks - Mainly Data -- Star Connectivity with large Hub - - TDM /TDMA Access -This is the classic definition of (VSAT Network ) . Circuit Switched Networks - Mainly voice - Mesh connectivity - SCPC or Low Rate TDMA Access VSAT Communication Remote to Hub TDMA HUB – TO – REMOTE ( TDM ) VSAT EQUIPMENT VSAT EQUIPMENT Primary Goal • Providing reliable performance and services at lowest possible cost. • Provide appropriate level of performance and services to different user on the basis of their needs. • Provide high speed networking to entire University campus as well as application based services. • Provide high speed of Internet access in order to appropriate utilization of e-journals provided by INFLIBNET Center. • Conducting e-learning program through RSU-CAN • System must be able to handle heavy network load. DHCP Server Graphical View of Firewall Solution Client Reservation • Client Reservation • Client Reservation is used to be sure a computer gets the same IP address all the time. Therefore since DHCP IP address assignments use MAC addresses to control assignments, the following are required for client reservation: • MAC (hardware) address • IP address How Managing Network • • • • • • • Central hub is installed at ERNET India Center, Banglore connected to VSAT facility with DAMA Phone of University.The central hub controls the entire operation of the communication network. At the hub there is a network management system server which allows a network administrator to monitor and control the networks. Two DNS server installed at ERNET Banglore IP Add. 202.141.99.9 and 202.41.1.131 Technical person of ERNET is monitoring bandwidth and traffic of network. University can get status about network. Graphical view of used bandwidth by university can be seen on “www.ugcinfonet.ernet.in/bwview.asp “ . If network generate undesired packets, they inform to University and accordingly takes decision what to do. Some time University used to do disconnect the segment getting undesired packets. Servers are equipped with trial version of anti virus, anti spy ware package. Trial version of Bandwidth monitoring software is using locally. Trial version of Network view software is using for Network Monitoring. Graphical View of Bandwidth taken from www.ugcinfonet.ernet.in/bwview.asp Daily Graph of 02/09/06 Weekly Graph Monthly Graph Yearly Graph Blue color is Transmit Traffic, Green color is Receive Traffic Typical Hub Scenario VSAT EQUIPMENT Applications & Benefits • • • • • • • • • • • wide geographic coverage high availability flexible network configuration rapid network deployment Centralized NMS. Cost Effective Bandwidth On Demand, Pay what you use. Internet Video Teleconferencing Bank transactions, ATM Reservation systems Problems. 1. 2. 3. 4. 5. 6. Since Web server installed here, hackers may access the computers and server without valid authentication for steeling the information, hacking may also lead to interception of the information from network. So some sort of security measures need to be employed to control traffic as well as hacking. Virus and spy ware problems at user end, which is the cause of Router Jam. Internet access speed suddenly gets slowed down. Some terminal runs with proper Internet access speed while some suffers form slow access speed. It may cause of virus, spy ware or unequal distribution of bandwidth. At present got 1 Mbps bandwidth where 256 kbps is provided for transmission of data and 1 Mbps is for receiving data while about 150 PCs are connected with this Network Like any other wireless communication technology information transmitted via VSAT network could be intercept or interfered by a third party. Suggested Solutions 1. A Router on dedicated connections to the Internet should be plugged . in to firewall system 2. 3. Router should be configured with some filtering rules Proxy server may be used to monitor the traffic on the network and allowing users to to a limited number of services or some unwanted services may be blocked 4. 5. 6. 7. . Anti virus and anti spy ware should be install centrally or every PC should be equipped with same. Bandwidth management tool should be installed in order to monitor the network properly. Packet filtering, Application level filtering and Web filtering is needed in order to provide secured network. Currently using windows 2003 server and Most of the PCs with windows O/S, need to move to Linux based operating system in order to make network more reliable, Virus free and less expensive. Thank You ?