Bus and Ring...i memorize all arh!~

10board36
common standards broadband, coaxial cable, 10mbps, 3600 meters, can delivery concurrent data, popular but difficult to work.

two sub layer in data link
MAC sublayer
layout or format of the data frame, fields - error detection, workstation addressing.

Logical link control sublayer
provide error control.

CD
preamble,frame of bytes,data destination,source address,data length,data, PDA , checksum

token passing protocol
SD, AC, FC, DA, SA, data, checksum, ED, FS

token passing ring different with FDDI
standard token passing ring, workstation will know sizes of the transmit data, then will remove data from ring, passed to next workstation.
FDDI transmit multiple frame. end of token will add a frame then data will travel to next workstation, neighbor workstation will regenerate own frame. fast and wont take long time.

Bus and ring network.
bus-if the node is down. the network will not effect. CD.
easy to install and expand
delivery time not consitent

Ring- the node down,network will effect. token passing protocol.
high cost and hard to install.
delivery consitent

both same point is.
the node no need to control.
if network down,maybe the cable is broken.
both using token ring to enhance
every node in network will received the message.

active node and inactive node.
active node will capable to received/sending message.
inactive noce will incapable to received or sending message.