Computer Networking

Media is the connection between a sender(transmitter) and a receiver. You can divide media into two broad categories, conductive media (you can see and touch it, e.g. copper wire), and radiated media (can't see, e.g. infrared, microwave, wireless transmission).

Pv4 uses 32-bit (four-byte) addresses. which limits the address space to 4,294,967,296 (232) possible unique addresses. However, some are reserved for special purposes such as private networks (~18 million addresses) or multicast addresses (~270 million addresses). This reduces the number of addresses that can potentially be allocated for routing on the public Internet. As addresses are being incrementally delegated to end users, an IPv4 address shortage has been developing.

Point to Point connecting to a switch
Multiple VLAN’s
A high bandwidth data channel

generally its used for fail-over and reliability. obviously the more connections you have the more reliable your connection however you also have to be aware that the more connections you have on multi-point you also have more security risks involved versus point-to-point connections in which there is only one port to watch and secure which will lower your total surface of attack area.

You can't. Facebook has those records. You will need a court order to get them to hand it over. Good luck and use a better password.

It is now possible to see account activity based on IP addresses from "Account settings" -> "Security" -> "Active sessions" -> "edit".

It depends on the brand and the specs you want with your router. You can find an entry level router for about $50 bucks if you go online, and you may be able to find similar routers in store for not much more.

IP Web cameras are used for security reasons, for instance, you can install it in your hallway and connect to a router and in this way to monitor your hallway. Usually it's cheaper to use IP cameras then usual video cameras.

A database can be consider as a group of file which allow us the multiple ways of accessing the data stored while for a particular file system there is a fixed path of accessing data. Simply put, a file is a collection of bytes stored together. An example of a file could be a Text File (a collection of alphanumeric characters that, when put together, form a readable document) or a Bitmap Image File (a collection of bytes that software would then interpret as elements of an image). A database is a special type of file that holds many tables. Each table can hold many fields as well as records. Think of a table as a spreadsheet. Each column represents different fields, such as "UserID", "LastName", and "CityOfResidence". Each row represents a record, or an entry, in the table, such as an entry for John Smith who lives in Albuquerque. An example of a database would be one that has three tables: Books, Instructors, and Courses. Different fields in the "Books" table would be "Author", "Publisher", "Title", and "ISBN". Different records within "Books" would be, for example, an entry for "Learning Java in 20 Days" (Title) by John C. Doe (Author), published by ABC Publishing Co. (Publisher). Each table in a database requires one field to be designated as the Primary Key. This means that, in order to uniquely identify a record in a table, one field needs to be used. In a "Students" table, the "StudentID" could be used as the Primary Key, since no two records (students) can have the same Student ID. For "Books" it could be "ISBN", since that is unique per book title. Visually, a table would look something like this: "Books" Table {| ! ISBN ! Title ! Author ! Publisher ! 1234567 | "Learning Java" Bob Smith ABC Publishing ! 8675309 | "Plumbing Basics" Joe Public XYZ Inc. ! 6762786 | "American Literature" William Jones LMNOP Corp. Finally, keep the following in mind: a database is a type of file. Therefore, all databases are files, '''but''' not all files are databases. Any chunk of data you save is a file. Ten words of text in notepad, or a dozen images in a folder. Those are both files. A database is both a program to store and organize data, and make it searchable, and the data contained in it. I guess you could call a database a file as well, but they are typically large, and referred to as databases. You might search a product database for widgets of wool, orange in color, made in New Zealand. The result of that search you could also call a file. When database managment systems (DBMS) first were developed, they used multiple files per database, typically one file per table. Now days, most of the common DBMS systems use one file per database. A database is a type of file (or a group of files.) |}

The PS3 has a high speed gigabit ethernet connection in the back for hard wiring into your LAN/router/modem. You'll need a Cat5e or better, ethernet cable of suitable length to plug into both pieces of equipment. Enter the appropriate details in the network section of the PS3 setup menu and off you go! Then it's just down to the speed of your internet connection! My hard wired setup is great for playing online games. No delays in retrieving game info!

File transfer protocol

An important goal in peer-to-peer networks is that all clients provide resources, including bandwidth, storage space, and computing power. Thus, as nodes arrive and demand on the system increases, the total capacity of the system also increases. This is not true of a client-server architecture with a fixed set of servers, in which adding more clients could mean slower data transfer for all users. The distributed nature of peer-to-peer networks also increases robustness in case of failures by replicating data over multiple peers, and -- in pure P2P systems -- by enabling peers to find the data without relying on a centralized index server. In the latter case, there is no single point of failure in the system. When the term peer-to-peer was used to describe the Napster network, it implied that the peer protocol was important, but, in reality, the great achievement of Napster was the empowerment of the peers (i.e., the fringes of the network) in association with a central index, which made it fast and efficient to locate available content. The peer protocol was just a common way to achieve this.

The modern Ethernet cable is a Category 5 UTP cable, with an RJ 45 connector.

TracFone uses both Verizon and AT&T's network to provide service to their customers. The network you have depends on your location.

is a telex pin number is the same as your bank pin number that you used for your personal account

Just what the name implies, a server or simplified enclosure that allows you to store files locally on a local network. this can be in the form of a NAS hard drive where it is basic storage only or a full computer system that handles other server duties as well.

Advantages of TDMA

1. The user gets full bandwidth of the channel in a particuler time slot.

2. For bursty signals such as voice or speech TDMA gives maximum utilization of the channel

3. most suitable technique for digital transmission.

Disadvantages of TDMA

1. it is not much suitable for continues signals

2. extra guard time are necessary

3. synchronization is necessary.

data link layer

With broadband there is less need for web caching. Its definitely less heard off anyway. But pretty much, if you frequent a site on a server that is perhaps 18 hops away. It will take awhile for the page to get to you, so what happens is when you go onto a website a copy of the page is stored locally. Next time you request it, you are shown the copy on your computer. It's much faster to show you a page on your own computer then it is to get a page the other side of the network/internet. ISP's also cache popular pages too. So when one of their customers requests it, they have it pretty much ready to go.

A hub forwards packets it receives through one port to every other port on the device. A switch will read packet headers and identify which machines are connected to which port based on the information they send. Any packets addressed to those machines will only get sent to that port of the switch. A router looks at packet headers to determine which port it needs to forward a packet through, and also will translate packets between different protocols if needed. A router can also define subnets and will filter traffic as needed. Routers usually include DHCP, port forwarding capabilities and a whole host of other things usually controlled by software and therefore user customizable.
Hubs, Switches, Routers A Hub is, in its simplest form, just like a mains multiplug unit. There is no intelligence or circuitry in it. More complex units may incorporate an amplifier or repeater. The network signal goes into one port and out of all the others. This is a Layer 1 device. A Switch has a small level of intelligence, in that it can open a message, check the IP address, and direct the message packets to the port on which the device with that IP address resides. It cannot modify IP addresses or see addresses outside of the range of the 'home' network. This is a Layer 2 device. A Router can read IP addresses, and direct the messages to another network with different IP addresses to the originating network. The Router software can build up an address table, so that it 'knows' where other devices are. This is a Layer 3 device. CT

A typical IP address looks like this:
216.27.61.137

The internet uses a very complex topology, due to the massive number of nodes and the high redundancy that is characteristic of high availability systems like the internet. Different parts of the internet look like different topologies. The internet would be best approximated as a mesh topology.

For an image of a simple mesh topology, and a discussion of the different possible network topologies, see the wikipedia article in the links below.

It depends on the type of modem. Serial modems must be connected to a PC serial port and configured manualy. Serial modems are rarely ever used now. PCI modems must be installed into a spare PCI slot on the inside of the PC, the modem should auto configure. USB modems should be plugged into a USB port and like PCI modems should auto configure.

They all stand for some kind of computer area networks:- LAN's = Local Area Network, WAN's = Wide Area Network, MAN's = Metropolitan Area Network, HAN's = Home Area Network.