Specifications

Ethernet Network Design 7-3
10BASE5 Ethernet Network Design
A maximum length 10BASE5 coaxial cable has 199 annular rings marked
off at 2.5 m intervals. Because each transceiver tap introduces noise onto
the coaxial cable in the form of a small impedance discontinuity, and
contributes to the overall attenuation of the cable, IEEE has specified that
only 100 taps will be allowed on a 10BASE5 segment, with each tap
separated by a minimum of 2.5 m.
Once the coaxial taps are in place, they can be attached directly to the
transceivers (see Figure 7-3). An Attachment Unit Interface (AUI) cable is
used to connect devices such as workstations or file servers to the
transceivers. The AUI cable, which can be a maximum of 50 m in length, is
made up of four shielded twisted pairs that carry the transmit, receive and
collision signals between the transceiver and its connected equipment.
Figure 7-3. Transceiver Attachment
Multi-port Transceivers
As you recall from the previous Chapter 6, Ethernet Network Design, a
multi-port transceiver is a device that is used to connect several network
devices at a single tap point. This is useful when it is necessary to
concentrate a number of devices at one physical location or to add more
than 100 devices on a single coaxial backbone. A typical multi-port
transceiver has eight AUI ports for connection to workstations and one
AUI port for connection to the backbone segment.
TRANSCEIVER
Coax Cable
Contact Pin
AUI Connector
Non-Intrusive Tap
1913-20