Mixed media bridges

· Interconnect LANs of different types
· Example ethernet and token ring
· These differ in frame format, opeartion and speed and these issues to be taken
care of
· Since the frame formats are different reformatting is done and new FCS is used.
But adds processing overhead.
· Since the data rate is different the bridge should have sufficient buffering capacity
· Two approaches used are : translational bridging
source route transparent bridging

• used to concentrate connectivity
• combine the connectivity of a hub with the traffic regulation of a bridge
• switch frames from incoming ports to outgoing ports providing each port with full
• provide separate data paths
switch functions
– Address learning
– Forward/filter decision
– Loop avoidance