| More |

Latest News (more news)

4 Reasons Why Your Network Sucks

19 May 2012, 3:53 pm

Your network is a disaster in the making. It sucks. But why?

TalkTalk to make first foray into mobile contracts

18 May 2012, 3:07 am

TalkTalk will branch out into the mobile contract business and plans to increase its core network capacity by more than 100 times as part of its plans to stem revenue loss ( ZDNet UK - Mobile Devices )

Electric Imp Connects Your Home Devices to the Internet

18 May 2012, 1:19 am

If you've ever dreamed about connecting your entire home to the Internet -- so that appliances could start by themselves or you could receive text message alerts to maintain housekeeping -- it looks like your dream is ready to become a reality.

Computer's Networking

Computer's networking is achieved mainly using two types of devices: Switches and Routers. Switches provide OSI Layer 2 connectivity at a local level. Routers provide local and global OSI Layer 3 connectivity.

Switches are frequently installed for high-speed connectivity between end stations at the data link layer (OSI Layer 2). Switching technology has been around since the 1980s (then called Bridging). Switching involves segmentation of local-area networks (LANs) at the Layer 2 level. A multiport swicth typically learns about the Media Access Control (MAC) addresses on each of its ports and transparently passes MAC frames destined to those ports. These bridges also ensure that frames destined for MAC addresses that lie on the same port as the originating station are not forwarded to the other ports.

A Router is a more sophisticated network device than a switch. Each features a number of "ports" the front or back that provide the connection points for these computers, a connection for electric power, and a number of LED lights to display device status. While routers and switches all share similar physical appearance, routers differ substantially in their inner workings. Traditional routers are designed to interconnect multiple IP networks at Layer 3 level. On the Internet or on a large corporate network, for example, routers serve as intermediate destinations for network traffic. These routers receive IP packets, look inside each packet to identify the source and target IP addresses, then forward these packets as needed to ensure the data reaches its final destination.

Layer 3 Switches are a relatively new device. Layer 3 switches are routers with fast forwarding done via hardware. IP forwarding typically involves a route lookup, decrementing the Time To Live (TTL) count and recalculating the checksum, and forwarding the frame with the appropriate MAC header to the correct output port. Lookups can be done in hardware, as can the decrementing of the TTL and the recalculation of the checksum. The routers run routing protocols such as Open Shortest Path First (OSPF) or Routing Information Protocol (RIP) to communicate with other Layer 3 switches or routers and build their routing tables. These routing tables are looked up to determine the route for an incoming packet.

< Newer articles | Older articles >