Editing 100BaseVG (section)

==Physical layer==
The [[physical layer]] requires four [[twisted pair]]s of "voice-grade" cabling for a link, so Category 3 cables or better can be used. While control signaling uses two pairs for each direction simultaneously, all four pairs are switched to a single direction during data transmission, as required and defined during control signaling. This makes 100BaseVG an inherently [[half-duplex]] medium like e.g. [[10BASE5]] (yet faster) but without the [[CSMA/CD]] drawbacks.

100BaseVG also supports full-duplex operation over [[optical fiber]] or over two pairs of [[shielded twisted pair]].

{| class="wikitable" style="line-height:110%;"
|+Comparison of [[Ethernet over twisted pair|twisted-pair-based Ethernet]] physical transport layers (TP-PHYs)<ref name="TDG_ETH_2nd">{{cite book |title=Ethernet: The Definitive Guide |edition=2nd |author=Charles E. Spurgeon |publisher=O'Reilly Media |year=2014 |isbn=978-1-4493-6184-6}}</ref>
! Name
! Standard
! Status
! Speed (Mbit/s)
! Pairs required
! Lanes per direction
! Bits per hertz
! [[Line code]]
! [[Symbol rate]] per lane (MBd) 
! Bandwidth
! Max distance (m)
! Cable
! Cable rating (MHz)
! Usage
|-
| {{nowrap|100BaseVG}}
| {{nowrap|802.12-1995}}
| {{N/A|obsolete}}
| align="right" | 100
| align="right" | 4
| align="right" | 4
| align="right" | 1.{{overline|6}}
| align="right" | 5B6B ''Half-duplex only''
| align="right" | 30
| align="right" | 15
| align="right" | 100
| align="center" | [[Category 3 cable|Cat&nbsp;3]]
| align="right" | 16
| {{N/A|''Market failure''}}
|}