SFA's ResNet FAQ

What does an Ethernet connection look like on my computer and in the wall?
(Also see question 11 for how to check in your Windows Control Panel to determine if your computer already has an Ethernet adapter installed.) On a typical desktop computer system, the RJ-45 connector/port will look similar to a typical phone jack, only slightly larger (see Figure 8a). The hardware configuration of this particular computer system includes a typical modem (labeled at bottom), as well as two (2) network cards. One card is typical of many newer Ethernet network cards. It provides one RJ-45 port (circled in red) and uses a standard Ethernet (or Cat 5) cable. Most adapters will have LNK (link) and ACT (activity) lights visible next to the RJ-45 port (circled in green). You'll notice the RJ-45 adapter's indicator light is not as obvious (its the small square "dot" to the left of the port) as those on the wireless network adapter (recognizable by the attached antennae) installed in the expansion slot above it. On the wireless adapter, the lights are located just to the left of center on the card—one is amber and one is green.
          Figure 8a
Figure 8b

Some desktop systems have what is known as an "on-board" or "integrated" network adapter, which is included on the system's motherboard itself. In this case, the RJ-45 port will often be in close proximity to the other system ports for the mouse, keyboard, USB, serials, etc (see Figure 8b). In the case of laptops, notebooks, and other portables, the Ethernet adapter can also be integrated, as is the case with newer systems, but will often be in the form of a PC card (PCMCIA) and installed in a Type II slot. They typically connect to the network by means of a short cable adapter known as a dongle (see Figure 8c). Some newer adapters, however, do not use dongles and are, appropriately enough, known as dongleless adapters (see Figure 8d).

For examples and assistance in identifying Ethernet ports on Macintosh computers, refer to item 5 of the Connectivity Troubleshooting Guide for Mac Users.

Figure 8c

Figure 8d

Which wall-jack do I plug the Ethernet cable into?

The Ethernet cable should be plugged into the BLUE Ethernet jack. The majority of the Ethernet jacks installed in the residence halls on campus are blue in color and in close proximity to the phone jacks, which are gray. Typically both the phone and Ethernet jacks will be visible on the same faceplate mounted to the wall box. (see Figure 8e)

            Figure 8e
Telecommunications & Networking Dept.
Created: June 1, 2001
Last revised: November 30, 2003
Contact: resnet-webmaster@sfasu.edu