Thursday, January 8, 2009
Thursday, October 30, 2008
EACH CATEGORY
PORTAL:AOL,MSN
NEWS
NBC.COM
BUISNESS/MARKETING
NIKE.COM
EDUCATIONAL
PHOENIX UNIVERSITY
WEB CT
ENTERTAINMENT
INTERACTIVE & ENGAGING
OFFER/MUSIC,VIDEOGAMES,SPORTS,CHATS,SWEEPTAKES
ADVOCACY
OPINION,IDEA
BLOG
WIKI
ONLINE SOCIAL NETWORKS
FACEBOOKS
MYSPACE
CONTENT AGGREGATOR
BUISNESS
PERSONAL
INDIVUAL OR FAMILY CREATED
NEWS
NBC.COM
BUISNESS/MARKETING
NIKE.COM
EDUCATIONAL
PHOENIX UNIVERSITY
WEB CT
ENTERTAINMENT
INTERACTIVE & ENGAGING
OFFER/MUSIC,VIDEOGAMES,SPORTS,CHATS,SWEEPTAKES
ADVOCACY
OPINION,IDEA
BLOG
WIKI
ONLINE SOCIAL NETWORKS
FACEBOOKS
MYSPACE
CONTENT AGGREGATOR
BUISNESS
PERSONAL
INDIVUAL OR FAMILY CREATED
Wednesday, October 29, 2008
sub domains
the Domain Name System (DNS) hierarchy, a subdomain is a domain that is part of a larger domain.[1] For example, "mail.example.com" and "calendar.example.com" are subdomains of the "example.com" domain, which in turn is a subdomain of the "com" top-level domain (TLD).
Note that "subdomain" expresses relative dependence, not absolute dependence: for example, wikipedia.org comprises a subdomain of the org domain, and en.wikipedia.org comprises a subdomain of the domain wikipedia.org. In theory, this subdivision can go down to 127 levels deep, and each DNS label can contain up to 63 characters, as long as the whole domain name does not exceed a total length of 255 characters. But in practice some domain registries have shorter limits than that.
A subdomain is sometimes termed a vanity domain, especially when it is a subdomain of an ISP's own domain aliased to an individual user account. However, the term "vanity domain" has other usages, discussed at that article.
Some websites use different subdomains to point to different server clusters. For example, www.example.com points to Server Cluster 1 or Datacentre 1, and www2.example.com points to Server Cluster 2 or Datacentre 2, etc.
Subdomains are commonly used by organizations that wish to assign a unique name to a particular department, function, or service related to the organization. For example, a university might assign "cs" to the computer science department, such that a number of hosts could be used inside that subdomain, such as mail.cs.example.edu or www.cs.example.edu.
Depending on application, a record inside a domain, or subdomain might refer to a Host name, or a service provided by a number of machines in a cluster
Free Subdomains or Free Subdomain services are Free Url Redirection services that provide free short url in form of a subdomain, e.g. http://username.smth.com, but that free subdomain is longer than 3 symbols
Note that "subdomain" expresses relative dependence, not absolute dependence: for example, wikipedia.org comprises a subdomain of the org domain, and en.wikipedia.org comprises a subdomain of the domain wikipedia.org. In theory, this subdivision can go down to 127 levels deep, and each DNS label can contain up to 63 characters, as long as the whole domain name does not exceed a total length of 255 characters. But in practice some domain registries have shorter limits than that.
A subdomain is sometimes termed a vanity domain, especially when it is a subdomain of an ISP's own domain aliased to an individual user account. However, the term "vanity domain" has other usages, discussed at that article.
Some websites use different subdomains to point to different server clusters. For example, www.example.com points to Server Cluster 1 or Datacentre 1, and www2.example.com points to Server Cluster 2 or Datacentre 2, etc.
Subdomains are commonly used by organizations that wish to assign a unique name to a particular department, function, or service related to the organization. For example, a university might assign "cs" to the computer science department, such that a number of hosts could be used inside that subdomain, such as mail.cs.example.edu or www.cs.example.edu.
Depending on application, a record inside a domain, or subdomain might refer to a Host name, or a service provided by a number of machines in a cluster
Free Subdomains or Free Subdomain services are Free Url Redirection services that provide free short url in form of a subdomain, e.g. http://username.smth.com, but that free subdomain is longer than 3 symbols
Tuesday, October 28, 2008
A network operating system (NOS) is software that controls a network and its message (e.g. packet) traffic and queues, controls access by multiple users to network resources such as files, and provides for certain administrative functions, including security.
The upper 5 layers of the OSI Reference Model provide the foundation upon which many network operating systems are based
6WINDGate, 6WIND software packages that turn Linux distributions into routers's control plane and data plane.
Cisco IOS (formerly "Cisco Internetwork Operating System") is a NOS having a focus on the internetworking capabilities of network devices. It is used on Cisco Systems routers and some network switches.
BSD, also used in many network servers.
Android is a software platform and operating system for mobile devices, based on the Linux kernel, developed by Google and later the Open Handset Alliance.[2] It allows developers to write managed code in a Java-like language that utilizes Google-developed Java libraries,[3] but does not support programs developed in native code.[4]
The unveiling of the Android platform on 5 November 2007 was announced with the founding of the Open Handset Alliance, a consortium of 34 hardware, software, and telecom companies devoted to advancing open standards for mobile devices.[5] Google has pledged to make most of the Android platform available under the Apache free-software and open source license.[6]
The upper 5 layers of the OSI Reference Model provide the foundation upon which many network operating systems are based
6WINDGate, 6WIND software packages that turn Linux distributions into routers's control plane and data plane.
Cisco IOS (formerly "Cisco Internetwork Operating System") is a NOS having a focus on the internetworking capabilities of network devices. It is used on Cisco Systems routers and some network switches.
BSD, also used in many network servers.
Android is a software platform and operating system for mobile devices, based on the Linux kernel, developed by Google and later the Open Handset Alliance.[2] It allows developers to write managed code in a Java-like language that utilizes Google-developed Java libraries,[3] but does not support programs developed in native code.[4]
The unveiling of the Android platform on 5 November 2007 was announced with the founding of the Open Handset Alliance, a consortium of 34 hardware, software, and telecom companies devoted to advancing open standards for mobile devices.[5] Google has pledged to make most of the Android platform available under the Apache free-software and open source license.[6]
Friday, October 24, 2008
NIC- recieves the data packet from the network layer
Broadcast-a broadcast ia a signal sent
collision Domain-two or more devices transmit
Broadcast-a broadcast ia a signal sent
collision Domain-two or more devices transmit
Thursday, October 23, 2008
topology
The way in which geographical elements are related to each other. The topology of the data must be defined before GIS analysis can be performed.
A bus network topology is a network architecture in which a set of clients are connected via a shared communications line, called a bus. There are several common instances of the bus architecture, including one in the motherboard of most computers, and those in some versions of Ethernet networks.
Bus networks are the simplest way to connect multiple clients, but may have problems when two clients want to transmit at the same time on the same bus. Thus systems which use bus network architectures normally have some scheme of collision handling or collision avoidance for communication on the bus, quite often using Carrier Sense Multiple Access or the presence of a bus master which controls access to the shared bus resource
A ring network is a network topology in which each node connects to exactly two other nodes, forming a circular pathway for signals - a ring. Data travels from node to node, with each node handling every packet.
Because a ring topology provides only one pathway between any two nodes, ring networks may be disrupted by the failure of a single link. A node failure or cable break might isolate every node attached to the ring. FDDI networks overcome this vulnerability by sending data on a clockwise and a counterclockwise ring: in the event of a break data is wrapped back onto the complementary ring before it reaches the end of the cable, maintaining a path to every node along the resulting "C-Ring". 802.5 networks -- also known as IBM Token Ring networks -- avoid the weakness of a ring topology altogether: they actually use a star topology at the physical layer and a Multistation Access Unit to imitate a ring at the datalink layer.
Star networks are one of the most common computer network topologies. In its simplest form, a star network consists of one central switch, hub or computer, which acts as a conduit to transmit messages. Thus, the hub and leaf nodes, and the transmission lines between them, form a graph with the topology of a star. If the central node is passive, the originating node must be able to tolerate the reception of an echo of its own transmission, delayed by the two-way transmission time (i.e. to and from the central node) plus any delay generated in the central node. An active star network has an active central node that usually has the means to prevent echo-related problems.
The star topology reduces the chance of network failure by connecting all of the systems to a central node. When applied to a bus-based network, this central hub rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network, sometimes including the originating node. All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only. The failure of a transmission line linking any peripheral node to the central node will result in the isolation of that peripheral node from all others, but the rest of the systems will be unaffected.
[edit]
A bus network topology is a network architecture in which a set of clients are connected via a shared communications line, called a bus. There are several common instances of the bus architecture, including one in the motherboard of most computers, and those in some versions of Ethernet networks.
Bus networks are the simplest way to connect multiple clients, but may have problems when two clients want to transmit at the same time on the same bus. Thus systems which use bus network architectures normally have some scheme of collision handling or collision avoidance for communication on the bus, quite often using Carrier Sense Multiple Access or the presence of a bus master which controls access to the shared bus resource
A ring network is a network topology in which each node connects to exactly two other nodes, forming a circular pathway for signals - a ring. Data travels from node to node, with each node handling every packet.
Because a ring topology provides only one pathway between any two nodes, ring networks may be disrupted by the failure of a single link. A node failure or cable break might isolate every node attached to the ring. FDDI networks overcome this vulnerability by sending data on a clockwise and a counterclockwise ring: in the event of a break data is wrapped back onto the complementary ring before it reaches the end of the cable, maintaining a path to every node along the resulting "C-Ring". 802.5 networks -- also known as IBM Token Ring networks -- avoid the weakness of a ring topology altogether: they actually use a star topology at the physical layer and a Multistation Access Unit to imitate a ring at the datalink layer.
Star networks are one of the most common computer network topologies. In its simplest form, a star network consists of one central switch, hub or computer, which acts as a conduit to transmit messages. Thus, the hub and leaf nodes, and the transmission lines between them, form a graph with the topology of a star. If the central node is passive, the originating node must be able to tolerate the reception of an echo of its own transmission, delayed by the two-way transmission time (i.e. to and from the central node) plus any delay generated in the central node. An active star network has an active central node that usually has the means to prevent echo-related problems.
The star topology reduces the chance of network failure by connecting all of the systems to a central node. When applied to a bus-based network, this central hub rebroadcasts all transmissions received from any peripheral node to all peripheral nodes on the network, sometimes including the originating node. All peripheral nodes may thus communicate with all others by transmitting to, and receiving from, the central node only. The failure of a transmission line linking any peripheral node to the central node will result in the isolation of that peripheral node from all others, but the rest of the systems will be unaffected.
[edit]
Wednesday, October 22, 2008
DSL
"DSL" redirects here. For other uses, see DSL (disambiguation).
A DSL Modem
Comparing DSL & Dial-Up
DSL or xDSL, is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop, although in recent years, the term digital subscriber line has been widely adopted as a more marketing-friendly term for ADSL, which is the most popular version of consumer-ready DSL. DSL uses high frequency, while regular telephone uses low frequency on the same telephone line.
Typically, the download speed of consumer DSL services ranges from 256 kilobits per second (kbit/s) to 24,000 kbit/s, depending on DSL technology, line conditions and service level implemented. Typically, upload speed is lower than download speed for Asymmetric Digital Subscriber Line (ADSL) and equal to download speed for the rarer Symmetric Digital Subscriber Line (SDSL).
A DSL Modem
Comparing DSL & Dial-Up
DSL or xDSL, is a family of technologies that provides digital data transmission over the wires of a local telephone network. DSL originally stood for digital subscriber loop, although in recent years, the term digital subscriber line has been widely adopted as a more marketing-friendly term for ADSL, which is the most popular version of consumer-ready DSL. DSL uses high frequency, while regular telephone uses low frequency on the same telephone line.
Typically, the download speed of consumer DSL services ranges from 256 kilobits per second (kbit/s) to 24,000 kbit/s, depending on DSL technology, line conditions and service level implemented. Typically, upload speed is lower than download speed for Asymmetric Digital Subscriber Line (ADSL) and equal to download speed for the rarer Symmetric Digital Subscriber Line (SDSL).
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