token ring это

Ответ от Cheery[гуру]
у Token Ring одно кольцо, а у FDDI - два
у TR один узел является монитором, задающим скорость передачи данных, у FDDI - его имеет каждое кольцо
работа TR основа на битах приоритета и резевра, у FDDI приоритет основан на так называемом Token Rotation Time
это же приводит к различию формату фреймов и как обрабатывается трафик
Similarities
- FDDI uses a rotating ring setup in the same way as the token ring protocol.
- FDDI's ring operation is basically very similar to the Token Ring early release operation in the way that tokens are passed on the network.
Differences
- As opposed to Token Ring's single ring, FDDI, uses two to achieve better results and less chance of failure.
- In a basic Token Ring network, at any instant there is a single active ring monitor which supplies the master clock for the ring, whereas in FDDI this approach isn't ideal because of the high data rates. Instead, each ring interface has its own local clock, and outgoing data is transmitted using this clock.
- Unlike the basic Token Ring, which is based on the use of priority and reservation bits, the priority operation of the FDDI ring uses a principle that is based on a parameter known as the Token Rotation Time, or TRT.
- FDDI uses a timed token protocol where Token Ring uses priority/reservation token access, leading to differences in frame format and how station traffic is handled
Источник:
Cheery
Высший разум
(199137)
Картинку по ссылке посмотрите.