Enterprise customers thinking of upgrading to faster 802.11n Wi-Fi have been warned that not all new access points (APs) deliver the promised performance gains.
Some of you might be thinking “theoretical models don’t help me” or “the OSI model is just some engineering thing for the nerds”. However, in reality, it is quite the opposite. The OSI model can help you. Let me show you how.
The standard model for networking protocols and distributed applications is the International Standard Organization's Open System Interconnect (ISO/OSI) model. It defines seven network layers.
Short for Open System Interconnection, an ISO standard for worldwide communications that defines a networking framework for implementing protocols in seven layers. Control is passed from one layer to the next, starting at the application layer in one station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.
At one time, most vendors agreed to support OSI in one form or another, but OSI was too loosely defined and proprietary standards were too entrenched. Except for the OSI-compliant X.400 and X.500 e-mail and directory standards, which are widely used, what was once thought to become the universal communications standard now serves as the teaching model for all other protocols.
Control is passed from one layer to the next, starting at the application layer in one station, proceeding to the bottom layer, over the channel to the next station and back up the hierarchy.
Every network admin is going to have trouble with network links on a Cisco router, at one point or another. The best way to troubleshoot any networking issues is to use the OSI model and go layer by layer. In this article, you will find out how to use the OSI model to troubleshoot, bottom up, using a Cisco router.
A security researcher has claimed that Yahoo's system for blocking automated access to its systems - the CAPTCHA image-recognition system - has been effectively cracked.
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