P2P (Networking):

Definition: The term P2P refers to “peer-to-peer” networking. A peer-to-peer network allows computer hardware and software to function without the need for special server devices. P2P is an alternative to client-server network design.

P2P is a popular technology for file sharing software applications like Kazaa, WinMX and Overnet. P2P technology helps the P2P client applications upload and download files over the P2P network services.

P2P technology can also be found in other places. Microsoft Windows XP (starting with Service Pack 1), for example, contains a component called “Windows Peer-to-Peer Networking.” P2P is especially popular in homes where an expensive, decidated server computer is neither necessary nor practical.

Finally, the P2P acronym has acquired a non-technical meaning as well. Some people have described this second meaning of “P2P” as “people-to-people”. From this perspective, P2P is a model for developing software and growing businesses that help individuals on the Internet meet each other and share common interests. So-called social networking technology is an example of this concept.

Dial UP Connection:

Definition: Dial up networking technology provides PCs and other network devices access to a LAN or WAN via standard telephone lines. Dial up Internet service providers offer subscription plans for home computer users.

Types of dial up services include V.34 and V.90 modem as well as Integrated Services Digital Network (ISDN). Dial up systems utilize special-purpose network protocols like Point-to-Point Protocol (PPP).

To use a dial up Internet connection, a client modem calls another modem located at the Internet Service Provider (ISP). The modems transfer network information over the telephone until one modem or the other disconnects.

When the popularity of the Internet exploded in the 1990s, dial up was the most common form of Internet access due mainly to its low cost to setup. However, the performance of dial up networking is relatively poor due to the limitations of traditional modem technology. V.90 modem dial up supports less than 56 Kbps bandwidth and ISDN handles approximately 128Kbps.

Many home users are currently replacing their dial up services with high-speed broadband technologies that operate at much higher speeds.

Broadband & DSL:

Definition: The term broadband refers to any type of transmission technique that carries several data channels over a common wire. DSL service, for example, combines separate voice and data channels over a single telephone line. In DSL, voice fills the low end of the frequency spectrum and data fills the high end.

In home networking, broadband constitutes any form of high-speed Internet access using this transmission technique. Both DSL and cable modem are common broadband Internet technologies. So-called broadband routers and broadband modems are network devices that support both DSL and cable. Other forms of home broadband include fiber (FTTH) and fixed wireless.

To qualify as a broadband Internet service, the technology should as a general guideline support network bandwidth of at least 256 Kbps for connections in one direction.

Definition: DSL is a high-speed Internet service like cable Internet. DSL provides high-speed networking over ordinary phone lines using broadband modem technology. DSL technology allows Internet and telephone service to work over the same phone line without requiring customers to disconnect either their voice or Internet connections.

DSL technology theoretically supports data rates of 8.448 Mbps, although typical rates are 1.544 Mbps or lower.

DSL Internet services are used primarily in homes and small businesses. DSL Internet service only works over a limited physical distance and remains unavailable in many areas where the local telephone infrastructure does not support DSL technology.

What Is a Layer 3 Switch?

Traditional network switches operate at Layer 2 of the OSI model while network routers operate at Layer 3. This often leads to confusion over the definition of “Layer 3 switch.”

A Layer 3 switch is a high-performance device for network routing. Layer 3 switches actually differ very little from routers. A Layer 3 switch can support the same routing protocols as network routers do. Both inspect incoming packets and make dynamic routing decisions based on the source and destination addresses inside. Both types of boxes share a similar appearance.

Layer 3 switches were conceived as a technology to improve on the performance of routers used in large local area networks (LANs) like corporate intranets. The key difference between Layer 3 switches and routers lies in the hardware technology used to build the unit. The hardware inside a Layer 3 switch merges that of traditional switches and routers, replacing some of a router’s software logic with hardware to offer better performance in some situations.

Layer 3 switches often cost less than traditional routers. Designed for use within local networks, a Layer 3 switch will typically not possess the WAN ports and wide area network features a traditional router will always have.

switch (network switch):

Definition: A network switch is a small hardware device that joins multiple computers together within one local area network (LAN). Technically, network switches operate at layer two (Data Link Layer) of the OSI model.

Network switches appear nearly identical to network hubs, but a switch generally contains more intelligence (and a slightly higher price tag) than a hub. Unlike hubs, network switches are capable of inspecting data packets as they are received, determining the source and destination device of each packet, and forwarding them appropriately. By delivering messages only to the connected device intended, a network switch conserves network bandwidth and offers generally better performance than a hub.

As with hubs, Ethernet implementations of network switches are the most common. Mainstream Ethernet network switches support either 10/100 Mbps Fast Ethernet or Gigabit Ethernet (10/100/1000) standards.

Different models of network switches support differing numbers of connected devices. Most consumer-grade network switches provide either four or eight connections for Ethernet devices. Switches can be connected to each other, a so-called daisy chaining method to add progressively larger number of devices to a LAN.