PA Computer Networking:

If your company or small business has a need to connect their computers together to share resources (Internet Access, printers, plotters, CD-ROM's, storage/HD, etc) - Nyetech can help!

We can install and support Hubs, Switches, Routers, WiFi, and Bridges - as well as appropriate Category 5e or 6 wiring and connections. Switches are usually wired together via fiber. In addition, we can install firewalls to secure your network yet also allow Virtual Private Networking (VPN).

For information on what these terms mean, read below.

Contact us if you would like to discuss your needs!

Hub

A hub is a repeater. It basically takes the data that comes into a port and sends it out all the other ports in the hub. It doesn't perform any filtering or redirection of data. Although it's actually a little more complicated, you can think of a hub like a piece of wire. A better analogy might be that of an Internet Chat room. Everything that everyone who joins a particular chat is seen by everyone else. If there are too many people trying to chat, things get bogged down.

Bridge

Bridges do not know anything about protocols, and just forward data depending on the destination address in the data packet. This address is not the IP address, but the MAC (Media Access Control) address that is unique to each network adapter card.

Bridges are very useful for joining networks made of different media types together into larger networks, and keeping network segments free of data traffic that doesn't belong in a particular segment.

Switches

Switches are the same thing as Bridges, but usually have multiple ports with the same "flavor" connection (Example: 10/100BaseT).

Switches can be used in heavily loaded networks to isolate data flow and improve performance. In a switch, data between two lightly used computers will be isolated from data intended for a heavily used server, for example. Or in the opposite case, in "auto sensing" switches that allow mixing of 10 and 100Mbps connections, the slower 10Mbps transfer won't slow down the faster 100Mbps flow.

Although switch prices are dropping so that there is very little difference from hub prices, most home users get very little, if any, advantage from switches, even when sharing "broadband" Internet connections. However, small business users of say 10+ clients, may benefit from the use of a Switch instead of a Hub.

Router

Routers forward data packets from one place to another, too! However routers forward data depending on the Network address, not the Hardware (MAC) address. For TCP/IP networks, this means the IP address of the network interface.

Routers isolate each LAN into a separate subnet, so each network adapter's IP address will have a different third "octet" (Example: 192.168.1.1 and 192.168.2.1 are in different subnets.). They are necessary in large networks because the TCP/IP addressing scheme allows only 254 addresses per (Class C) network segment.

Routers, like bridges, provide bandwidth control by keeping data out of subnets where it doesn't belong. However, routers need to be set up before they can get going, although once set up, they can communicate with other routers and learn the way to parts of a network that are added after a router is initially configured.

Routers are also the only one of these four devices that will allow you to share a single IP address among multiple network clients.

Firewall

This is a tool designed to prevent unauthorized access to or from a private network. Firewalls can be implemented in both hardware and software, or a combination of both. Firewalls are frequently used to prevent unauthorized Internet users from accessing private networks connected to the Internet, especially intranets. All messages entering or leaving the intranet pass through the firewall, which examines each message and blocks those that do not meet the specified security criteria.

There are several types of firewall techniques:

Network Address Translation: An Internet standard that enables a local-area network (LAN) to use one set of IP addresses for internal traffic and a second set of addresses for external traffic. A NAT box located where the LAN meets the Internet makes all necessary IP address translations. NAT provides a type of firewall by hiding internal IP addresses

Packet filter: Looks at each packet entering or leaving the network and accepts or rejects it based on user-defined rules. Packet filtering is fairly effective and transparent to users, but it is difficult to configure. In addition, it is susceptible to IP spoofing.

Application gateway: Applies security mechanisms to specific applications, such as FTP and Telnet servers. This is very effective, but can impose a performance degradation.

Circuit-level gateway: Applies security mechanisms when a TCP or UDP connection is established. Once the connection has been made, packets can flow between the hosts without further checking.

Proxy server: Intercepts all messages entering and leaving the network. The proxy server effectively hides the true network addresses.

In practice, many firewalls use two or more of these techniques in concert.

A firewall is considered a first line of defense in protecting private information. For greater security, data can be encrypted.

Click one of the links in the right-hand column, for additional information!