Network cabling, or wiring is the physical link between all nodes and networking devices on your network. Cabling is available in three basic varieties: twisted-pair (UTP), thin Ethernet (coax), and thick Ethernet. The two most common types for small networks are the twisted-pair and thin Ethernet.
The Intel® InBusiness™ products use twisted-pair cabling because it is the most economical and easily maintainable Ethernet media. Many Intel products are available with RJ-45 ports (for twisted-pair cabling), and/or BNC connections (for network coax cable). Cables and connectors are described in detail in this document.
When planning your network, the cost of cabling should always be a factor. The cable you choose for your network today will likely be in place for a long time. If you are planning on expanding the network or moving into Fast Ethernet products, you may want to start with a higher grade of cable now.
A cable used for both network communications and higher-grade telephone communications. Also known as UTP (unshielded twisted-pair) or STP (shielded twisted-pair), and 10BASE-T/100BASE-TX cable. Used primarily in "Star" networks. Uses RJ-45 connectors.
Thin Ethernet Coax
Usually quarter-inch black coaxial cable, identified by type such as RG-58/U. Sometimes called network coax, 10BASE 2, or thinnet cable. Uses BNC connectors.
Also called standard Ethernet, or thicknet, it is used with 10Mbps baseband networking. It is often used as a backbone cable. Thick Ethernet is heavy, stiff, and difficult to install, and is the most expensive wired cabling used. Uses AUI connectors.
An Ethernet networking system that transmits data at 100 Mbps. Known as 100BASE-TX, it is similar to 10BASE-T Ethernet, only 10 times faster and of higher quality. Uses RJ-45 connectors.
What is UTP?
UTP (unshielded twisted-pair or "stranded" cabling) comes in both Category 3 (10BASE-T for 10 Mbps networking) and Category 5 (100BASE-TX for 100 Mbps Fast Ethernet networking). It is thin, flexible and easy to use with the common RJ-45 connector. The two main advantages of twisted-pair networks are the low cost of the cables, and the ease of installation in a star network.
Another major advantage is its ability to quickly resolve failed connections. In a twisted-pair network, if a connection fails somewhere on the network between a node and the hub, only that node is disabled; the rest of the network is unaffected (except for the inability to access that node). Usually, replacing one segment of cable at the failed node will fix the problem. If the failure occurs in the link between two hubs, the two hubs continue to operate separately, although they are isolated from each other's network resources.
When it comes time to expand your network, twisted-pair cable is particularly useful. Using a commercially available twisted-pair "crossover" cable, you can connect your existing hub directly to another hub, switch or bridge without complication. (See also "RJ-45 Straight-through Ports" and "RJ-45 Crossover Ports.")
Unlike coax cable, twisted-pair cable with RJ-45 connectors will provide connection information between your computer and the network connection. This status will usually be displayed by a light on your hub.
This cable type is used with a Star topology. Remember, each segment of wire must not exceed 100 meters (about 328 feet).
Quality Cable Standards
Networking standards specify cable types for use in 10 Mbps and 100 Mbps Ethernet networks. Category ratings depict the quality or ability to carry data; the higher the category, the better the cable, and therefore, more reliable data. UTP cable should be stamped with the rating (category) clearly marked on the plastic covering.
Your home phone cabling is likely a Category 1 and uses RJ-11 connectors; smaller than the RJ-45 used in networking. Some commercial installations use Category 3 cabling for telephone connections. Network connections cannot be made with Category 1; use only Category 3 or 5.
Category 3 UTP
Category 3 is used for network and data transmission operating at 10 Mbps. Category 3 should never be used with 100 Mbps Fast Ethernet networks.
Category 5 UTP
Category 5 is required for network and data transmission operating at 100 Mbps (Fast Ethernet). This cable grade can be used successfully for 10 Mbps operation, but it is slightly more expensive than Category 3. If you will be upgrading to 100Mbps in the near future, you should consider installing your network with Category 5 cable now.
Coax cabling is similar to but higher quality than cable TV or antenna cabling. There are two types of coax cable used on a network: thin (10BASE 2) and thick (10BASE 5). Because 10BASE 5 is rarely used in small networks, only thin Ethernet is being described. Remember, in a coax bus or backbone network, if a single connection fails, the entire network may be disabled.
10BASE-2 (or network coax bus or backbone cable) is also called thinnet. Thin coax cable is similar to but of higher quality than your home TV and VCR cable. The cable should be clearly marked with RG-58/U stamped on the casing. It is usually quarter-inch coax cable and connects to your network with a BNC connector.
Thinnet is reasonably flexible and is very reliable. While it is more expensive than 10BASE-T cable, it is often the choice for small networks using a bus topology.
Connectors and Ports
10BASE-T cable uses RJ-45 connectors that connect to RJ-45 connector ports on most Intel InBusiness networking products. RJ-45 connectors are similar in design to your modular telephone connectors; just a little larger. They click quickly and easily into the port, making a very secure connection.
BNC (coax) Connectors
A BNC connector is a high quality connector found on high-end electronic equipment. It is somewhat similar to the "RCA jack" found on most newer TV's and VCR's. The BNC connector must be aligned carefully, pushed into place and twisted clockwise to lock in place, making a very secure connection. BNC/coax cable connections do not provide connection status information between your computer and the network connection. Terminate all open ends of a BNC connector to prevent signal bounce with a 50 ohm terminator.
RJ-45 Straight-Through Ports
A straight-through port is the standard port on most hubs, switches, bridges, etc. It may also be called a 10BASE-T port. It allows direct connection from a node to the connecting equipment. The media used is a 10BASE-T cable with RJ-45 modular connectors. You cannot tell by looking at the port whether it is a standard or crossover port. Your manufacturer's documentation will detail the ports and inform you of port types being used.
RJ-45 Crossover Ports
A crossover port is usually marked with an "X" for easy identification. This specially configured RJ-45 port is provided on some networking devices to allow easier connection when cascading (connecting) from one hub or switch to another; for example, when connecting multiple hubs or multiple switches, allowing expansion of the network. When using a device with a crossover port, a standard, straight-through cable is all that is required. The equipment manufacturer's documentation will inform you when this special type of port is present on your networking device and what type of cable is needed.
BNC (coax) Ports
The BNC connection on some networking devices is provided to facilitate connection to a coax cable (also called 10BASE 2 or thinnet).
Twisted-Pair Network Cable Guide
||Maximum number of nodes|
||10 Mbps Star
||100 Mbps Star
||10 Mbps or 100 Mbps (cascade)
||10 Mbps=Cat. 3
100 Mbps=Cat. 5
|10 Mbps=100 Meters
100 Mbps=5 Meters
COAX Network Cable Guide
||Maximum number of nodes|
(Also known as Thin, Thinnet, or BNC)
NETWORKING 5- 4- 3 Rule:
A LAN can have as many as five cable segments (not exceeding the maximum length), connected by four hubs or switches, but only three sections can have computers attached.
Also, if using BNC both ends of a cable segment must be terminated to prevent signal bounce.
This applies to: