CHAPTER 5
OTHER LAN TECHOLOGIES
Large Ethernet networks, including:
Hierarchical switch organization to reduce cost,
Single points of failure,
Workgroup versus core switches
Virtual local area networks and Ethernet physical layer standards.
Wireless LANs Including:
802.11 speeds
802.11 access points and hand-offs,
CSMA/CA + ACK,
Bluetooth master/slave operation
Spread spectrum transmissions (box features)
ATM LANs Including:
Quality of service (QoS) guarantees for voice and video (but not necessarily for data)
ATM preparation using meshes and virtual circuits to reduces switching costs
Comparisons between ATM and Ethernet in handling brief traffic peaks
Legacy LANs Including:
token -ring networks and early Ethernet standards
LARGER ETHERNET NETWORKS
In a hierarchy There is only on possible path between any two station
Ethernet Requires hierarchical arrangement for its switches
LOW-COST SWITCHING Advantage.
Ethernet switches only have to do simple table lookups when a frame arrives
Simple table lookups are very fast
Making Ethernet switches very inexpensive for the traffic load they handle
Note: routers have to do more work
because there are alternative routes between any two stations
Must identify all possible routes
Then select the best route
WORKGROP VERSUS CORE SWITCHES
Workgroup switches Connect stations directly to switches
Carry traffic to and from their stations (previous chapter)
Dominant port speed
10/100Mbps
Core switches Are switches farther up the hierarchy
They carry traffic between one switch and another
They must work faster than workgroup switches
Have to handle traffic of many workgroup switches
Emerging dominant port speed
1Gbps
10Gbps
VIRTUAL LANs AND ETHERNET SWITCHES
Unicasting Ethernet NICs normally wish to unicast
Send a from a from one station to one other station
Broadcast Send message to all stations
Novel Netware servers may advertise there presence every 60 seconds for so by broadcasting a server advertisement message that is designed to go to all to the...