100VG-Any LAN

100VG-AnyLan (VG =Voice Grade) is a joint development of AT&T Microelectronics, Hewlett-Packard, and IBM and is standardized by the newly created IEEE 802.12 committee. 100VG-AnyLAN supports Ethernet, Token Ring, and other LAN standards, incorporating a collision less polling technique. It is not that simple as it appears. A router upgrade is required to connect 100VG Ethernet and 100VG Token Ring.

1. Distances are
2. 100 meters for Cat 3 UTP (4 pairs)
3. 150 meters for Cat 5 UTP (2 pairs) and Type 1 STP (2 pairs)
4. 2000 meters for fiber
5. The specifications suggest that higher speeds are possible. All pairs are used for transmission in half-duplex mode at 25 MHz
6. Priority access is provided through the DPMA (Demand Priority Media Access) technique
7. 100VG-AnyLAN can be deployed in a scalable star topology.