Editing 10BASE5 (section)

==Network design and installation==
For its [[Ethernet physical layer|physical layer]] 10BASE5 uses cable similar to RG-8/U [[coaxial cable]] but with extra braided shielding. This is a stiff, {{convert|0.375|in|adj=on}} diameter cable with an impedance of 50&nbsp;[[Ohm (unit)|ohms]], a solid center conductor, a foam insulating filler, a shielding braid, and an outer jacket. The outer jacket is often yellow-to-orange [[fluorinated ethylene propylene]] (for fire resistance) so it often is called "yellow cable", "orange hose", or sometimes humorously "frozen yellow garden hose".<ref>{{cite book |title=All-in-One Networking+ Certification Exam Guide |author=Mike Meyers |edition=3rd |publisher=McGraw-Hill |date=2004 |page=79}}</ref> 10BASE5 coaxial cables had a maximum length of {{convert|500|m|sp=us}}. Up to 100 nodes could be connected to a 10BASE5 segment.<ref>{{cite web |url= http://computernetworkingnotes.com/n_plus_certifications/10base_ethernet.htm |title= 5-4-3 rule |access-date= 2010-06-30 |archive-date= June 11, 2010 |archive-url= https://web.archive.org/web/20100611104753/http://computernetworkingnotes.com/n_plus_certifications/10base_ethernet.htm |url-status= dead }}</ref>

[[Transceiver]] nodes can be connected to cable segments with [[N connector]]s, or via a ''[[vampire tap]]'', which allows new [[node (networking)|node]]s to be added while existing connections are live. A vampire tap clamps onto the cable, a hole is drilled through the outer shielding, and a spike is forced to pierce the outer three layers and contact the inner conductor while other spikes bite into the outer braided shield. Care is required to keep the outer shield from touching the spike; installation kits include a "coring tool" to drill through the outer layers and a "braid pick" to clear stray pieces of the outer shield.

Transceivers should be installed only at precise 2.5-meter intervals. This distance was chosen to ''not'' correspond to the signal's wavelength; this ensures that the reflections from multiple taps are not in phase.<ref>{{Citation | title = IEEE Standard 802.3-1985 | pages = 121 | isbn = 0-471-82749-5 | publisher = [[IEEE]] | author = Technical Committee on Computer Communications of the IEEE Computer Society | year = 1985}}</ref> These suitable points are marked on the cable with black bands. The cable is required to be one continuous run; T-connections are not allowed.

As is the case with most other high-speed buses, segments must be [[Electrical termination|terminated]] at each end. For coaxial-cable-based Ethernet, each end of the cable has a 50&nbsp;ohm resistor attached. Typically this resistor is built into a male N connector and attached to the cable's end just past the last device. With termination missing, or if there is a break in the cable, the signal on the bus will be reflected, rather than dissipated when it reaches the end. This reflected signal is indistinguishable from a [[Carrier-sense multiple access with collision detection|collision]] and prevents communication.