Wednesday, August 3, 2011

Unicast,Multicast,Broadcast

Unicast:Unicast traffic is traffic addressed to a single device on the network.Unicast packets are sent from host to host. The communication is from a single host to another single host. There is one device transmitting a message destined for one reciever.Unicast uses IP delivery methods such as Transmission Control Protocol (TCP) and User Datagram Protocol (UDP), which are session-based protocols. When a Windows Media Player client connects using unicast to a Windows Media server, that client has a direct relationship to the server.

Multicast:Multicast is a special protocol for use with IP. Multicast enables a single device to communicate with a specific set of hosts, not defined by any standard IP address and mask combination. This allows for communication that resembles a conference call.Multicast is a true broadcast. The multicast source relies on multicast-enabled routers to forward the packets to all client subnets that have clients listening. There is no direct relationship between the clients and Windows Media server. The Windows Media server generates an .nsc (NetShow channel) file when the multicast station is first created. Typically, the .nsc file is delivered to the client from a Web server.

Broadcast:Broadcast is when a single device is transmitting a message to all other devices in a given address range. This broadcast could reach all hosts on the subnet, all subnets, or all hosts on all subnets. Broadcast packets have the host (and/or subnet) portion of the address set to all ones. By design, most modern routers will block IP broadcast traffic and restrict it to the local subnet.

Friday, July 29, 2011

IEEE Standards

IEEE 802.1 Bridging (networking) and Network Management
IEEE 802.2 Logical link control (upper part of data link layer)
IEEE 802.3 Ethernet (CSMA/CD)
IEEE 802.4 Token bus (disbanded)
IEEE 802.5 Defines the MAC layer for a Token Ring (inactive)
IEEE 802.6 Metropolitan Area Networks (disbanded)
IEEE 802.7 Broadband LAN using Coaxial Cable (disbanded)
IEEE 802.8 Fiber Optic TAG (disbanded)
IEEE 802.9 Integrated Services LAN (disbanded)
IEEE 802.10 Interoperable LAN Security (disbanded)
IEEE 802.11 Wireless LAN & Mesh (Wi-Fi certification)
IEEE 802.12 demand priority (disbanded)
IEEE 802.13 Not Used
IEEE 802.14 Cable modems (disbanded)
IEEE 802.15 Wireless PAN
IEEE 802.15.1 (Bluetooth certification)
IEEE 802.15.4 (ZigBee certification)
IEEE 802.16 Broadband Wireless Access (WiMAX certification)
IEEE 802.16e (Mobile) Broadband Wireless Access
IEEE 802.17 Resilient packet ring
IEEE 802.18 Radio Regulatory TAG
IEEE 802.19 Coexistence TAG
IEEE 802.20 Mobile Broadband Wireless Access
IEEE 802.21 Media Independent Handoff
IEEE 802.22 Wireless Regional Area Network

Tuesday, July 26, 2011

Ethernet

The ethernet is a system for connecting computers within a building using hardware running from machine to machine. It differs from the Internet, which connects remotely located computers by telephone line, software protocol and some hardware. Ethernet uses some software (borrowed from Internet Protocol), but the connecting hardware was the basis of the patent (#4,063,220) involving newly designed chips and wiring. The patent* describes ethernet as a "multipoint data communication system with collision detection".

In simple terms ethernet is the most common LAN (Local Area Network) technology in use today.Ethernet was developed by Xerox in the 1970s, and became popular after Digital Equipment Corporation and Intel joined Xerox in developing the Ethernet standard in 1980.Ethernet was officially accepted as IEEE standard 802.3 in 1985.
The original Xerox Ethernet operated at 3Mbps. Ethernet networks up to 10Gbps now exist.

Ethernet uses CSMA/CD when transmitting packets. The Carrier Sense Multiple Access with Collision Detection (CSMA/CD) is an algorithm, for transmitting and receiving packets over a common network hardware medium, by aiding in avoiding transmission collisions. The network is checked for other transmissions; when the way is clear, the computer transmissions can begin. If a collision is detected the packet is retransmitted later.

Saturday, July 23, 2011

Routing Tables

A routing table is an electronic document that stores the routes to the various nodes in a computer network. The nodes may be any kind of electronic device connected to the network. The Routing Table is usually stored in a router or networked computer in the form of a database or file. When data needs to be sent from one node to another on the network, the routing table is referred to in order to find the best possible route for the transfer of information.

Almost all computers and network devices connected to Internet use routing tables to compute the next hop for a packet. It is electronic table that is stored in a router or a networked computer. The routing table stores the routes (and in some cases, metrics associated with those routes) to particular network destinations. This information contains the topology of the network immediately around it. The construction of routing table is the primary goal of routing protocols and static routes.

Routing tables can generally be maintained manually when the network is small and static. The routing tables for all static network devices never change unless and until the administrator of the network changes them manually. In dynamic routing, the devices themselves automatically build and maintain their own routing tables. They do this by exchanging information regarding the network topology using routing protocols. This enables the devices in the network to automatically adapt to the changes in the network like device failures and network congestion as and when they occur.

Thursday, July 21, 2011

Network Topologies

In this post we are going to discuss about the type of network topologies that are available to a network administrator.Based on the requirement he can select any of them.In this post we will also see for which type of network which type of topology suited most.

A network topology is like a framework, although purely in virtual terms. A topology is a layout of how computers should connect, not how they are physically arranged in a space.

Bus Topology:

The most common network topologies include the bus topology, which connects all the computers with a single cable. The computers are all able to see when a machines taps into the wire to connect to another machine, however privacy is assured as only the connecting units can access the data. This arrangement work well with less devices, it’s easy enough to set up (10Base-2 ("ThinNet") and 10Base-5 ("ThickNet") cables work well). However the downside is that if the connecting cable fails all the units attached cannot interact.

Ring Topology:
The second one is the ring topology, typically used in schools; the arrangement is such that each unit is connected to two other units, hence like a ring. If one of the units crashes however the whole network ceases to function properly (FDDI, SONET, or Token Ring technology are good for implementing this topology).

Star Topology:

Next, the star topology typically has a hub (hub, router or switch) to which all units are connecting using a unshielded twisted pair cable. The benefits of this type are that if a unit crashes, the network still continues to function. The downside is that more cable is required.

Tree Topology:
The tree topology consists of a number of star topologies connected through a bus topology. Confusing? It’s actually quite simple; we simple connect the central hubs of the star networks in the form of a bus topology. This type of network is easy to expand.

Mesh Topology:
The mesh topology uses routes, therefore any messages transferred can take a number of routes to get to their destination, in a full mesh network, every device connects to every other device.

The type of topology you choose to implement really depends on you requirements, so look carefully at the number of units involved and how complicated your network is expected to be.

Tuesday, July 19, 2011

Golf Platzreife

Golf is now the emerging game that is popularized among all the people. Earlier only the rich and educated people played it. Now the popularity of the game is wide spread, so that every one has interest in playing the game. This particular game attracts all the types of crowds regardless of their age. Many people are now interested in learning this game. Mainly students involve themselves in this game so much and are very eager to learn the game. They are interested in learning in all the nuances, rules and regulations of the game. Since many people are interested in learning the game, there are many golf academies newly erecting in and around the city. Golf academies bear the responsibility to teach the young generation about the game. The rules of the golf etiquette are the first and fore most things, the golf academies teach their students. The rules of the game mainly aim at the safety of the golfers and to the pace of the play, which helps in keeping the game enjoyable. The golf etiquette is an essential part of the game. This is something very vital that all the new comers and the new beginners should learn on the course. For any game to be played successfully, the instruments used for the play should be manufactured or prepared with utmost care and you can found all these instruments at their Golf shop. A standard set of a golf club mainly consists of three woods, eight irons and a putter. Actually according to the rules and regulations of the play a golfer is allowed to carry 14 clubs in the bag. The more clubs the player carries the easier is his victory. To know more about golf academies, please visit Golfkurse.
The above site explains you all the details about the game. They are one of the largest German golf shops with a full range of all brand names. You can also visit Golf Platzreife it will be useful for you.

Thursday, July 14, 2011

Ideal Destination for Golf Lovers

A truly exciting sport that requires patience and skill. The sport of men. The Sport of sophisticates. The sport of men with way too much money. Jokes aside but, no gaming console is really complete without its own golf game.

Yesterday I was visiting some sites on golf club house locations and in those the one that i really found interesting is Whisper Rock Golf Course Homes.They provides you such a wonderful location in Scottsdale area that is ideal for any golf course home.

The whisper rock country club is nestled in amongst meandering hillsides and is laid out in a jungle setting. This golf course has some of the most beautifully designed holes on the Eastern side. The 18-hole course is carved through a virgin forest of full-grown trees that make for excellent playing under mature conditions.

Fairways and greens are kept in excellent condition. Utilizing water hazards, dog-legs and four island greens to good effect, the relatively short 18-hole course is well suited for golfers of all levels.

Greens are fast and generally have large undulations making reading the correct line especially important. The narrow palm tree lined fairways make it a challenge to recover from errant tee shots. Adding to the difficulty is also the relative long distance between the tees and the fairways. Shorter tee shots often wind up in the difficult to hit out of semi rough.

If you have any doubt or queries regarding buying or selling the club house in the space you can always contact to Holm Group that will help you in exploring more.