Computer Networking

Piggybacking is a term used to refer to access of a wireless internet connection by bringing one's own computer within the range of another's wireless connection, and using that service without the subscriber's explicit permission or knowledge. It is a legally and ethically controversial practice, with laws that vary in jurisdictions around the world. While completely outlawed in some jurisdictions, it is permitted in others. A customer of a business providing hotspot service, such as a hotel or cafe, is generally not considered to be piggybacking, though non-customers or those outside the premises may be. Many such locations provide wireless Internet access as a courtesy to their patrons, either with or without an extra charge, or simply to draw people to the area.[1]

You use a Rj-45 connector with twisted-pair cabling in an Ethernet LAN. Rj-45 is a connector with a 4 5 wiring sequence.

Many premium channels such as HBO scramble their signals so that people cannot get these for free on their television sets. A descrambler is a gadget that allows you to restore the picture and sound of a scrambled channel by "unlocking" the signals. A descrambler has to be used in combination with a cable converter. Both these devices are perfectly legal although it may not seem so. You can get a converter from your cable company and attach a descrambler to it or you can purchase both the devices on your own and use them to access channels. What is illegal though is if you do not inform the cable company that you are receiving their signals. If you do not pay for these services, then it becomes illegal. There are many descramblers and converters available in the markets. These also vary in their cost depending on the quality and features that you want and also if you want a new one or are alright with buying an old one. A combination descrambler/converter device is also available. This is a one piece set top box with an in-built descrambler. The converter lets you access the cable channels on a television that is not cable ready, and the built-in descrambler allows you to view premium channels. A descrambler cannot work with any cable signals but has to be compatible to the signals provided by the cable company in your area. So you cannot just pick it up and attach it to a television that is served by another cable service.

Basically a layer 2 switch operates utilizing Mac addresses in it's caching table to quickly pass information from port to port. A layer 3 switch utilizes IP addresses to do the same.

While the previous explanation is the "What", for folks in networking the following "How" is far more interesting.

Essentially, A layer 2 switch is essentially a multiport transparent bridge. A layer 2 switch will learn about MAC addresses connected to each port and passes frames marked for those ports. It also knows that if a frame is sent out a port but is looking for the MAC address of the port it is connected to and drop that frame. Whereas a single CPU Bridge runs in serial, todays hardware based switches run in parallel, translating to extremly fast switching.

Layer 3 switching is a hybrid, as one can imagine, of a router and a switch. There are different types of layer 3 switching, route caching andtopology-based. In route caching the switch required both a Route Processor (RP) and a Switch Engine (SE). The RP must listen to the first packet to determine the destination. At that point the Switch Engine makes a shortcut entry in the caching table for the rest of the packets to follow. Due to advancement in processing power and drastic reductions in the cost of memory, today's higher end layer 3 switches implement a topology-based switching which builds a lookup table and and poputlates it with the entire network's topology. The database is held in hardware and is referenced there to maintain high throughput. It utilizes the longest address match as the layer 3 destination.

Now when and why would one use a l2 vs l3 vs a router? Simply put, a router will generally sit at the gateway between a private and a public network. A router can perform NAT whereas an l3 switch cannot (imagine a switch that had the topology entries for the ENTIRE Internet!!). In a small very flat network (meaning only one private network range for the whole site) a L2 switch to connect all the servers and clients to the internet is probably going to suffice. Larger networks, or those with the need to contain broadcast traffic or those utilizing VOIP, a multi network approach utilizing VLANs is appropriate, and when one is utilizing VLANs, L3 switches are a natural fit. While a router on a stick scenario can work, it can quickly overtax a router if there is any significant intervlan traffic since the router must make complicated routing decisions for every packet that it recieves.

MOdulator-DEModulator, by names of processes which perform the main role in modems.

The minimum size of an Ethernet frame is 64 bytes. Even if the VLAN tag is 4 bytes, the Ethernet frame with VLAN tagging remains 64 bytes.

'IP number' is actually called IP address. You can find out your IP address along with other usefull information about your computer at www.IKnowYour.info

Application Layer

A referral to the file's actual location.

The Nyquist theorem defines the maximum bit rate of a noiseless channel.

Yes. A router is simply a "distributor" of the connection.

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Simple assign the range in the DHCP Server after excluding some IPs For the Network Server(s).

But if suppose you have already assigned the range and want to configure a static IP for the server in that range only, then just add the exclusion range in DHCP that you don't want DHCP to use for distribution. Exclusion range can be of one IP also.

Hope this helped

-- By MyNarutoAnime

The best topology is ring topology.

Star is the next best after ringr, and then bus, which is pretty old, but not too expensive.

Full mesh topology is theoretically the best since every device is connected to every other device, thus maximizing speed and security. These, however, are quite expensive to install. The next best would be tree topology, which is basically a connection of stars.

BitTorrent is the name of a peer-to-peer (P2P) file distribution client application and also of its related file sharing protocol, both of which were created by programmer Bram Cohen. BitTorrent is designed to distribute large amounts of data widely without incurring the corresponding consumption in costly server and bandwidth resources. CacheLogic suggests that BitTorrent traffic accounts for ~35% of all traffic on the Internet,[1] while other sources are skeptical.[2] The original BitTorrent application was written in Python. Its source code, as of version 4.0, has been released under the BitTorrent Open Source License, which is a modified version of the Jabber Open Source License. There are numerous compatible clients, written in a variety of programming languages, and running on a variety of computing platforms. BitTorrent clients are programs which implement the BitTorrent protocol. Each BitTorrent client is capable of preparing, requesting, and transmitting any type of computer file over a network using the BitTorrent protocol. This includes text, audio, video, encrypted content, and other types of digital information. BitTorrent is a file transfer protocol. For more information, try this site: http://www.bittorrent.com/about.html

A LAN is a Local Area Network, for example in your house or the computers that are connected at work. It is different from a WAN, or Wide Area Network, which is where a computer or a LAN is hooked up to the internet.

There are various advantages and disadvantages to traveling by a bus. An advantage is that it is environmentally friendly. A negative is that it can take a long time.

254 - a class C subnet uses 8 bits for the hosts and 0 and 255 are reserved.

A typical network consists of one or more hubs, switches and routers. They all do similar jobs, however hubs are cheaper because all traffic from one port is broadcast across all other ports. They are "dumb".

Switches are more intelligent (and thus more expensive) and will quickly "learn" which IP addresses are connected to which ports. When a message is initially broadcast across all ports for a given IP address, only one port will respond (if at all), and the switch will then associate that port with the IP address for all future messages, reducing congestion across all other ports. This is why whenever a new machine is introduced to the network (or an existing machine goes offline), there is often a "lag" on the network while the switches figure out the new topology.

A router is the same as a switch but it is also programmable; it is really a computer in its own right. Routers typically provide two or more network interfaces allowing two or more otherwise separate networks to be linked. The router acts as the gateway between those networks. Your home broadband router is a typical example, linking your home network (the local area network) to the Internet (the wide area network). A side-effect of routers is that a machine outside the LAN cannot initiate communications with a local machine; the local machine must initiate all communications outwith the LAN. As far as the WAN is concerned, only the router is visible, but the router uses network address translation (NAT) to route legitimate communications to the correct local machine. All illegitimate communications are simply ignored. A router typically provides a hardware firewall which can be configured to limit the type of (legitimate) communications that may be permitted either to or from the local area network.

Switches, hubs and routers may be daisy-chained or arranged in a star configuration, or a combination of the two. Each switch is linked to one or more network access points and computers connect to the network via these access points.

Access points can also be made available using Wi-Fi, utilising Wi-Fi extenders or repeaters as necessary to increase the range.

Wired connections are typically achieved using CAT5 or CAT5e cabling (8-core, twisted-pair), however network switches are typically linked via CAT6 or, in some cases, fibre optic cabling.

Internet with capital 'I' refers to the Internet as in the world wide web, and what most people think of when you say internet.

Internet with a lowercase 'i' refers to a bunch of small LANS connected together to form some kind of host-to-host packet delivery service. So basically Internet capital I refers to inter-networking at the global level. Whereas internet with a lowercase 'i' refers to it on a much smaller level.

Hubs and Switches

By calling the pizza guy.....

PRESS THE ON BUTTON ¬.¬

Data modulation is a method of Electronic packing of data. In Data communication data is transmitted through a process which is called "Data Modulation".

If your referring to cat5, cat5e, cat6 wire, what you have is two wires that carry voltage, when voltage travels on wire it creates a magnetic field around the wire, you have two wires that carries voltages and both wires are creating a magnetic field... then you have eddy currents... take two magnetic and bring them close together and you disturb there magnetic fields or crossing of eddy currents as you disturb there magnetic field you feel the resistance or how it becomes harder to bring them closer together. The resistance of the magnetic fields is the same on two conductors they resist flow. So if you twist the two pairs together somehow it helps to cancel or reduce the repulsion of the fields and allow the voltage to flow better or more efficiently. the tighter or more twist per length the better.

change the dns setting and config your dns, monitor all the traffic with any network sniffer.