Networks

Networks

Introduction

Before describing the various connecting devices that exist in the networks, first I have to explain the TCP / IP is used by Internet.TCP / IP are two protocols (TCP and IP) is a set of protocols covering the different levels of the OSI model (Open Systems Interconnection). TCP (Transmission Control Protocol), is translated Protocol Transmission Control Protocol and IP (Internet Protocol), translated means Internet Protocol. The TCP protocol is responsible for managing the data and check for errors in transmission. The IP protocol is responsible for transporting data packets from one place to another. TCP / IP is compatible with any operating system and any hardware and is the most widely adopted architecture for the interconnection of systems. Contrary to what happens with OSI (open systems interconnection), the TCP / IP software, that is, a model to be implemented in any type of network. Facilitates the exchange of information regardless of the technology and type of cross subnets, providing seamless communication across heterogeneous systems. The TCP / IP and OSI is divided into levels, and is trying to pass information to adjacent levels. The number of levels varies according to the network. Each level n of a machine communicates with other machines at no peer calling process. To establish a communication each level, starting with the highest, sends information to the adjoining lower level to the level lower than directly accessing the physical media. On the target machine information shall remain the way up until you reach the next level. To normalize the levels structured networks in the International Organization for Standardization (ISO) proposed the OSI Reference Model (Open Systems Interconnection). The OSI system has 7 levels which are: Physical, Link, Network, Transport, Session, Presentation and Application. Each of these levels is done by a piece of hardware and / or system software.

Now we will discuss some famous model of Cisco routers which can be used for wired networking.

1. Cisco 857 Integrated Router (4 Port Switch)

Its belongs to Cisco 850 family series as a wireless router & for a secured broadband, or it can also be use with the analog phone wire system for small offices specially,it have 4 port and can be placed outside as a external device with a flash memory of not more then 20 Mb with networking protocol of L2TP,PPPoE,PPTPand support th e data link of Ethernet

2. CISCO857-K9 - Cisco 857 Integrated

Another product from Cisco, it have VPN protections, access control list, it's a DSL modem with 4 port secondly it has the option of weighted queuing option, and it can support ADSL2, ADSL etc.

3. Cisco 850 Series integrated

This model can support 802.11b if one is interested in wireless networking, with a very easy setup of installation with 4 port switch option.

4. Cisco 851

Again this is also a good model with all VPN support and ADSL options but the main drawback of this model is that it cannot support the 802.11b option, it's a 10/100 Mbps Ethernet model with the option of 4 ...