Monday, March 9, 2009

Building Peer-to-peer connection

1. Create a simple peer-to-peer network between two PCs.

Connect two PCs to create a simple peer-to-peer Ethernet LAN between two workstations. The workstations will be directly connected to each other without using a hub or switch. The computers must also be configured with the correct IP network settings so that they can communicate . A category 5/5E UTP crossover cable is needed. This is very useful for transferring files and for troubleshooting interconnecting devices between PCs. Two Workstations required with an Ethernet 10/100 NIC installed.

2. Identify the Proper cable to connect the two PCs.

Locate a crossover cable that is long enought to reach from one PC to the other, attach one end to the NIC in each PCs.

3. Configure workstation IP address Information

Assigned a valid IP address for each PCs included subnest mask, default gateway. Note that the default gateway IP Address is not required, since this computers are directly connected.

Wndows XP users follow this steps: 1. click on start > settings> Control panel and then click Network connection icon. 2. Select Local Area Network connection and click on change settings of this connection. 3. Select TCP/IP protocol icon that is associated with the NIC in this PC.
4. Click on prperties and click on use the following IP address.

Example: PC 1 IP address Subnet MASK
PC 2 IP address Subnet mask

4. Test Connectivity using ping commands

Access the command or MS-DOS prompt. Windows XP : start>Progarms>Accessories>Command Promp.

Verify that PCs can communicate; Test connectivity from one PC to the other by pinging the IP address of the opposite computer.

EXample: c:>ping
or c:> ping

what was the result?

example result :

Pinging 192.168.1. with 32 bytes of data:

Reply from : bytes=32 time<1ms TTL=150
Reply from : bytes=32 time<1ms TTL=150
Reply from : bytes=32 time<1ms TTL=150
Reply from : bytes=32 time<1ms TTL=150

Ping statistics for
Packets: sent = 4, Received = 4, Lost = 0 (0% loss),
Approximate round trip times in mili-seconds:
Minimum = Oms, Maximum = Oms, Average = Oms

Computer quotes

"The computer will become the hub of a vast network of remote data stations and information banks feeding into the machine at a transmission rate of a billion or more bits of information a second. Laser channels will vastly increase both data capacity and the speeds with which it will be transmitted. Eventually, a global communications network handling voice, data and facsimile will instantly link man to machine--or machine to machine--by land, air, underwater, and space circuits. [The computer] will affect man's ways of thinking, his means of education, his relationship to his physical and social environment, and it will alter his ways of living... These forces] will coalesce into what unquestionably will become the greatest adventure of the human mind." --- David Sarnoff, President of RCA, **1964**

huh! Just read this quotes this early morning and I am really amazed by this quotes . How about you?

Friday, March 6, 2009

LAN & WAN Devices

LAN & WAN Devices consist of different devices such as router, hub switch, gateway and more. This devices link up all the local and remote network segments with each other. The two important devices of network are Routers and Switches.

LAN Devices:

A hub is a networking device, which is used to connect the two segments of a wired network.

A network switch performs the same functionality in a network as a hub except a different that switch does not broadcast the data packets to all the computers in a network like a hub. A network switch has multiple ports like 4, 8, 16 and 24 etc. All the computers in a wired network are directly connected with the switch through Ethernet cable. Switches limit the traffic to and from each port and all the devices connected to the switch has maximum available bandwidth. Switch doesn’t provide the built-in firewall capabilities like the routers. In the telecommunication and packet switched infrastructure switches play an important role. They transmit the data towards its destination based on the IP address.

LAN card, network interface card or NIC is used to join the computers in a network. A NIC card is installed in any available PCI port inside the computer.

A gateway can be hardware or software and it acts as a bridge between two networks. A gateway is an entrance point of a network. A gateway connects a LAN with internet. A router acts as a gateway device in a network. In big networks, a computer server which acts as a gateway also acts as a proxy server and a firewall server. A gateway computer is usually attached with the router and switch.

A repeater is a network device that is used to retransmit the weaker signals in a network. A repeater receives the signals on the electromagnetic or optical transmission mediums. Repeater removes the unwanted noise from the incoming signals.

WAN Devices:

A router is a network communication device that is used to connect two or more logically and physically different networks. A router can be used to connect a LAN to LAN, LAN to WAN and LAN to internet. A router acts as a post office where sorting and distribution of the posts (packets in case of routers) is done. A router works on the basis of an IP address. Every router has built-in operating system known as IOS. A router works on the network layer of the OS model and it routes the data towards the optimal path. Router uses the header information of the packets and forwarding table to define the best shortest possible path of the data.

ISDN Adaptors

ISDN (Integrated Services Digital Network) is a data communication method and it is used over the regular telephone lines. To use the ISDN lines, you need to install add-on adapters known as ISDN terminal adapters. ISDN Terminal Adapter works like a digital modem i.e. it converts the signals from digital to analog and vice versa. ISDN Terminal adapter is plugged into the serial port of the system. Some ISDN adapters have the feature of switching between digital and analog modes.


CSU/DSU stands for channel service unit and data service unit. CSU is used to connect a terminal to a digital line. DSU is used to perform the protective and diagnostic functions of the telecommunication line. CSU/DSU is a network device of the size of an external modem. The Channel service unit receives and transmits the signals from the wide area network line. CSU/DSU are two separate devices and they are sometimes used in conjunction with the T1 LAN cards.


A bridge is a network communication device that is used to connect two segments of a LAN that uses the same protocol. Bridge is like a router but it doesn’t analyze the data before sending. A bridge operates at the data link layer of the OSI model and it can be used to connect the physically different networks and the networks that use the different protocols such as Ethernet and Token Ring.


A modem is communication device that performs two different functions such as modulation and demodulation i.e. it converts the digital data into analog and analog into digital. The faster types of the modems are used by the internet such as DSL modem, cable modem and optical modems. The features like BPS, auto answer, data compression, voice/data, fax capability and flash memory distinguish one modem from the other.


Network bridge and router combined together to form a device known as brouter.