Introduction to Client Server Networks

The term client-server refers to a popular model for computer networking that uses client and server devices each designed for specific purposes. The client-server model can be used on the Internet as well as local area networks (LANs).

Future of 4G Technologies Emerging

According to In-Stat reports, the primary 4G technologies are expected to be Long-Term Evolution, Ultra-Mobile Broadband and IEEE 802.16m WiMax. The International Telecommunication Union is expected to release an official definition of wireless 4G technology in 2008 or 2009.

Sophos Strengthens Next-Generation Web Security with WS1000

IT security and control firm Sophos today announced the latest version of its WS1000 web appliance, which brings together enterprise-grade policy and URL filtering with trusted real-time security filtering–all managed on one easy-to-use platform. The new Sophos solution enables businesses to effectively protect against growing web threats at the gateway, which are not adequately protected by current market offerings. The WS1000 also offers network administrators improved oversight and reporting of web browsing behaviors in their organization.

Sprint Nextel Plans $5 Billion for 4G Wireless Broadband Network

Sprint Nextel has indicated that it expects to spend more than $5 billion to build a nationwide 4G wireless broadband network. The carrier will market the services associated with the new network under the name Xohm.

Linksys Dual-Band Wireless-N Gigabit Router

The Dual-Band Wireless-N Gigabit Router is really four devices in one box. First, there's the dual-band Wireless Access Point, which lets you connect to the network without wires. There's also a built-in 4-port full-duplex 10/100/1000 Switch to connect your wired-Ethernet devices together at up to gigabit speeds. The Router function ties it all together and lets your whole network share a high-speed cable or DSL Internet connection

Smart Network Devices (SND) unveiled the world's smallest autonomous network camera at Embedded World 2003 in Nurnberg.

Smart Network Devices (SND) unveiled the world's smallest autonomous network camera at Embedded World 2003 in Nurnberg Measuring only 3 x 6 x 2cm and with an estimated material cost of under Eur 70.00 it sets new standards in network-supported security and video-surveillance technology

Connecting either to Ethernet or directly to the Internet, it carries out image compression at a speed capable of supporting M-JPEG at between 5 and 10frame/s.

The camera is a reference design, based on the SND Micro WebTarget board.

It uses the newest CMOS image-sensor technology and a Hyperstone 32bit RISC/DSP CPU for image compression.

Data from the sensor passes through a buffer unit to the CPU, where it is compressed into JPEG-format and then made available to the network through a 100Mbit/s Ethernet interface.

The small size and the low costs come from the minimising the system's hardware components.

The CMOS image sensor produces digital data, eliminating costly and expensive conversion of an analogue video signal.

The image sensor automatically handles the primary image processing (colour filter, automatic white balance, adaptive sensitivity according to light conditions, Gamma correction etc) so that downstream image processors are unnecessary.

Image compression into JPEG-format is through software.

The image acquisition and compression is under the control of SND's HyNetOS embedded network operating system.

This provides all necessary drivers (CMOS-sensor, Ethernet) and communication protocols (TCP/IP, HTTP, FTP) as well as a file system for plug-in to random networks or directly to the Internet.

A wireless variant of the network camera module, based on SND's Micro BlueTarget Bluetooth board, is planned for the 2nd quarter of 2003.

The corresponding Bluetooth-protocol-stack for HyNetOS is available now.

The network camera reference design is available now as an evaluation kit, complete with full hardware schematics for volume manufacturing.

The HyNetOS is available under license.

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Other hardware for establishing networks or dial-up connections

Other hardware for establishing networks or dial-up connections:

Multiplexer: device that combines several electrical signals into a single signal

Network Card: a piece of computer hardware to allow the attached computer to communicate by network

Modem: device that modulates an analog "carrier" signal (such as sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information, as a computer communicating with another computer over the telephone network

ISDN terminal adapter (TA): a specialized gateway for ISDN

Line Driver: a device to increase transmission distance by amplifying the signal. Base-band networks only.

Some hybrid network devices

Some hybrid network devices:

Multilayer Switch: a switch which, in addition to switching on OSI layer 2, provides functionality at higher protocol layers.

Protocol Converter: a hardware device that converts between two different types of transmissions, such as asynchronous and synchronous transmissions.

Brouter: Combine router and bridge functionality and are therefore working on OSI layers 2 and 3.

Digital media receiver: Connects a computer network to a home theatreHardware or software components that typically sit on the connection point of different networks, e.g. between an internal network and an external network:

Proxy: computer network service which allows clients to make indirect network connections to other network services* Firewall: a piece of hardware or software put on the network to prevent some communications forbidden by the network policyOther hardware for establishing networks or dial-up connections:

Multiplexer: device that combines several electrical signals into a single signal.

Network Card: a piece of computer hardware to allow the attached computer to communicate by network.

Modem: device that modulates an analog "carrier" signal (such as sound), to encode digital information, and that also demodulates such a carrier signal to decode the transmitted information, as a computer communicating with another computer over the telephone network.

ISDN terminal adapter (TA): a specialized gateway for ISDN.

Line Driver: a device to increase transmission distance by amplifying the signal. Base-band networks only.

Common basic network devices

About Computer Networking Device, here's the explamation : Common basic network devices:

Gateway: device sitting at a network node for interfacing with another network that uses different protocols. Works on OSI layers 4 to 7.

Router: a specialized network device that determines the next network point to which to forward a data packet toward its destination. Unlike a gateway, it cannot interface different protocols. Works on OSI layer 3.* Bridge: a device that connects multiple network segments along the data link layer. Works on OSI layer 2.* Switch: a device that allocates traffic from one network segment to certain lines (intended destination(s)) which connect the segment to another network segment. So unlike a hub a switch splits the network traffic and sends it to different destinations rather than to all systems on the network. Works on OSI layer 2.

Hub: connects multiple Ethernet segments together making them act as a single segment. When using a hub, every attached device shares the same broadcast domain and the same collision domain. Therefore, only one computer connected to the hub is able to transmit at a time. Depending on the network topology, the hub provides a basic level 1 OSI model connection among the network objects (workstations, servers, etc). It provides bandwidth which is shared among all the objects, compared to switches, which provide a dedicated connection between individual nodes. Works on OSI layer 1.

Repeater: device to amplify or regenerate digital signals received while setting them from one part of a network into another. Works on OSI layer 1.Some hybrid network devices:* Multilayer Switch: a switch which, in addition to switching on OSI layer 2, provides functionality at higher protocol layers.

different types of networks

topology : The geometric arrangement of a computer system. Common topologies include a bus, star, and ring. See the Network topology diagrams in the Quick Reference section of Webopedia.

protocol : The protocol defines a common set of rules and signals that computers on the network use to communicate. One of the most popular protocols for LANs is called Ethernet. Another popular LAN protocol for PCs is the IBM token-ring network .

architecture : Networks can be broadly classified as using either a peer-to-peer or client/server architecture.Computers on a network are sometimes called nodes. Computers and devices that allocate resources for a network are called servers.

MakSat WindMAX

High Power OFDM Radio Router/Bridge with Multiple modes like Access Point/Client/Bridge and operates in IEEE 802.11b/g standards. s.

Network Router

A network router is a small electronic device that allows you build a home network simply. The home router serves as the core or "centerpiece" of the network to which computers, printers and other devices can be connected. Networking with a router helps you to. For example you want to share files between computers, share an Internet connection between computers
share a printer, or connect your game console or other home entertainment equipment to the Internet.

Catalyst 6500 Series and 4500 Series routing switches

Cisco Systems, Inc. rolled out two enhancements to its Catalyst 6500 Series and 4500 Series routing switches. The new improvements are designed to better support peer-to-peer and real-time applications. They are the Cisco Catalyst 6500 Series Virtual Switching System 1440, which combines multiple Catalyst 6500 switches into one and scales system bandwidth capacity to 1.44 terabits per second; and the Cisco Catalyst 4500 E-Series with CenterFlex technology, which the company says it provides high network performance for rich applications.

"Business works differently now. Ideas come from everywhere. Negotiations and discussions come from everywhere. To keep pace, you need a different kind of network that can support apps that we haven't seen until now -- like Web 2.0 and telepresence," said Tere Bracco, senior manager of network systems at Cisco.

The Cisco Catalyst 6500 Series Virtual Switching System 1440 is enabled by the Virtual Switching Supervisor Engine 720 with 10 Gigabit Ethernet, hardware module that can make two 6500 switches behave and appear to administrators as one and costs $31,500.

The Cisco Catalyst 4500 E-Series with CenterFlex technology now delivers 320 gigabits per second and a fourfold increase in per-slot bandwidth using its unique centralized and flexible architecture. It provides 250 mpps (million packets per second) centralized performance and is based on Cisco's new CenterFlex technology which resulted in the filing of 19 new technology patents enhancing security, quality of service (QoS) and performance, the company claims.

PowerEdge M-Series

Packet Island, Inc. today announced that they will demonstrate their latest SaaS-based sniffer product, PacketPro at TMC's ITEXPO conference in Miami. This SaaS-based product has the ability to provide managed service providers and IT outsourcing companies remote visibility to troubleshoot problems in their customers' networks. Many companies don't have the internal networking staff to troubleshoot complex networking issues, especially voice over IP, which is time sensitive traffic. I haven't seen their product demo yet, so I'll be sure to stop by their booth. I believe they leverage Ethereal/WireShark, an open-source packet sniffing software. I know their solution supports SIP, SCCP (Cisco Skinny protocol), and Asterisk as reported by TMCNet.

PacketPro is a remote VoIP Lifecycle Management and Packet Sniffing solution. It consists of a 4" x 5" micro-appliance in a portable kit that can be shipped to a customer site. Packet Island's hosted service enables this micro-appliance to be used as a remote ethereal sniffer to diagnose a broad variety of network problems.

Cisco Announces New Data Center Concept with Nexus 7000

Cisco Systems Inc. will announce today a network switch for corporations, the Nexus 7000, which will allegedly provide a significant increase in traffic capacity over the company’s current products (the Catalyst series), to 15 trillion bits of data a second.

The Nexus 7000 combines Ethernet switching and storage capabilities into a single product and is designed to operate in corporate data centers. They will be powered by the NX-OS operating system, which will act as the brain of the data center. The Nexus Series of Cisco switches starts at $75,000 and will be available in the second quarter.

The Nexus project has required high research and development costs and the efforts of more than 500 engineers in the last four years, Cisco said. The new data center design proposed by Cisco will mean direct competition with server makers such as IBM and HP.

Difference Between Switch, Hubs and switch

Hubs and Switches serve for multiple computers together, and from the outside, they function identically they allow the connected computers to exchange data among themselves. However, the way they handle data internally is very different.

I copy this examples so that you can understand much better:

You can think of a hub like a house with 4 rooms, 4 people, and 4 phones but only one phone number. Each person has the phone to his ear, and they can converse with each other, but if one person speaks, everyone can hear it regardless if the statement was intended for them or not. So, if person 4 wanted to send a message to person 3, he would have to tell everyone to be quiet, say "this message is for person 3" and then say the message.
Figure 1 - 4 port hub.

Imagine the same situation except that each room has its own telephone number. This situation describes a switch. If person 4 wanted to send a message to person 3, he could call directly to that room without disturbing the people in rooms 1 or 2. That means that at the same time 3 and 4 are talking, room 1 and 2 could have a conversation without disrupting any other conversations.

The difference between a switch and a hub is that a switch can handle multiple communications between the computers attached to it whereas a hub handle one at a time. If there are only two computers transmitting data across a network, a hub would perform identically to a switch. However, if more than two computers were trying to transmit across the network at the same time, the switch would perform far better.

While router serves a slightly different function. A router is explicitly designed to connect two networks together, usually a Local Area Network, or LAN (like a single small office) to a Wide Area Network, or WAN (like the Internet). A router also has additional "smart" software with security features that disallow unauthorized access to the computers in the LAN from the outside.

host

A host is simply a computer (or server) that has a constant, high speed connection to the Internet. The importance of this is that this will allow your website to view worldwide over the internet. There are many host that are available today that gives the developer to view its website. Free web hosting are available today so that you can post your website on the internet for free this is a service which provides users with the ability to store web sites and media on the Internet for no cost. This is so good for all those who wanted to post the website with no cash involved.

The Server

From my previous post I had just said about the capability of the "client"and now I will post again about the server and what the server do or what the server can do, what's the services the server can offered. The Server allows or restrict the client from viewing the sites in the internet. The Server can directly interact to the client because of the power to manipulate whatever the server allows to the client. The server can manipulate the client in terms of restricting the client from accessing the unwanted sites by the server or just by saving your files in other client or folder. The server can block the internet data processing and many more, it has full accessed to the internet and if client want to view the restricted site the must have an approval of the server so that you can view it. The example of this is in internet cafe you notice that when you open example youtube.com there is a restriction of the site this restriction are cause by the server.

The Client

My own understanding about client is that it is an application or system that has a limitation accessing the services via WAN(Wide Area Network) and in LAN(Local Area Network). Client only interact to the services being allowed by the server but cannot interact directly to the server. Client does not have the power to view all the things that he wanted because the server the power to block some sites that the server wanted not to view. The client cannot have the authority to view the interested site if there is an existing server. The client can remotely interact with another client like for example transfering data to another client. The client can recieve files from another cumputer through LAN that give as a pathways of both client this makes them interact to each other.