networking - 1.pci bus 2.n computing, an interrupt request...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
1.pci bus 2.n computing, an interrupt request (or IRQ) is a phrase used to refer to either the act of interrupting the bus lines used to signal an interrupt, or the interrupt input lines on a Programmable Interrupt Controller (PIC). Interrupt lines are often identified by an index with the format of IRQ followed by a number. For example, on the Intel 8259 family of PICs there are eight interrupt inputs commonly referred to as IRQ0 through IRQ7. In x86 based computer systems that use two of these PICs, the combined set of lines are referred to as IRQ0 through IRQ15. Technically these lines are named IR0 through IR7, and the lines on the ISA bus to which they were historically attached are named IRQ0 through IRQ15. Newer x86 systems integrate an Advanced Programmable Interrupt Controller (APIC) that conforms to the Intel APIC Architecture. These APICs support a programming interface for up to 255 physical hardware IRQ lines per APIC, with a typical system implementing support for only around 24 total hardware lines. 3. Network connections are made possible by two main types of hardware: network media and network connectivity devices. This article is going to cover the later in enough detail to have you picking up the network-speak in no time.Network connection devices include: Network interface cards (NIC) Hubs Switches Bridges Routers Gateways Modems A NIC (network interface card) is a piece of hardware that allows you to plug in–or, interface with– a network cable. NIC’s are usually installed as an expansion card or is already built into your motherboard. Hubs are devices that connect all of the segments of a network together. That is, every device on the network (computers, printers) has a cable that is also connected to the hub. Hubs work in such a way that every signal that is received on one port is rebroadcast to every other device. So, if one device sends a signal, all the other devices receive the signal, but only one particular device listens for it. A switch is like a hub in that every device on the network is connected to it. However, a switch does not rebroadcast signals to all other devices. A switch makes a direct link between the device that is transmitting and the device that is receiving. All other devices are totally unaware of the communication taking place. For this reason, switches realize greater performance because bandwidth is not being wasted on needless rebroadcasting. A bridge is used to to keep network traffic separated between network segments. Traffic is not allowed to pass through the bridge unless its destination is on the other side. Bridges are used to join to network segments or to divide a busy network into two segments. Routers
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

networking - 1.pci bus 2.n computing, an interrupt request...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online