Download Network Topology Bus Topology Bus topology uses a common

Network Topology
Bus Topology
Bus topology uses a common backbone to connect all the network devices in a network in a linear
shape. A single cable functions as the shared communication medium for all the devices attached
with this cable with an interface connector. The device, which wants to communicate send the
broadcast message to all the devices attached with the shared cable but only the intended recipient
actually accepts and process that message.
Advantages
-easy to install
 dont need much cable
 computers can be detached without effect other computers
 cheap
disadvantages
 performance issue if more then 15 computers are added to the network
 if the backbone cable is broken then the network become useless and no communication
between the computers is possible
 its easy to sniff the traffic on the network
 all the traffic is tranfered over the same cable
Examples
10Base5
10Base2
Ring Topology
In ring Network, every computer or devices has two adjacent neighbors for communication.
In a ring network, all the communication messages travel in the same directory whether
clockwise or anti clockwise.
Advantages
-no kollision in the network
-all stations work as repeater
disadvantages
 if one computer or cable fails the network will breakdown
 hard to install
examples
Token ring
star topology
all computer are connected with a point to point connection to a central device
advantages
 if a cable is broken only the computer wich is connected to the cable can no longer
communicate with the network
 if a computer fails then the other computers are not affected
 easy extensible
 high transmission rate
disadvantages
 if the central device fails the network whole will brakdown
examples
telephone network
Ethernet
Tree Topology
advantages
 if a computer fails then the other computers are not affected
disadvantages
 if a central device fails all computer wich are connected to the central device are no longer
reachable
Mesh Topology
every computer will be connected to one ore more other computers. If every computer is
connected to every other computer, the network will be called complete meshed network
advantages
-the safest network variant
-if one computer faill the communication is still possible because the data will be redirected
disadvantages
-very hard to install(am härtesten zu installierende)
-much cable is necessary
Network Cable
BNC Cable
yellow cable
500 METER LONG
10 Mbit speed
10 mm Durchmesser
10Base5
Thinwire (10Base 2)
185Meter
30 stationen
Minimalabstand 0.5 milimeter
Enden müssen terminiert werden
Kabel Beschreibung
consist
Twisted Pair Kabel 10BaseT
100M
10-10000Mbit
Mehrere Categorie
CAT-1 für Alarmsysteme und analoge Sprachübertragung
CAT-2 für Sprache und RS232-Schnittstellen
CAT-3 Datenübertragung bis 10mbit
CAT-4 Datenübertragung bis
CAT-5 Datenübertragung bis 100 mbit
cat 5e gigabit ethernet
cat 6 gigabit ethernet
cat 7 10Gbit ethernet
cat 8 ??
Beschreibung der Kabel
//optional
LWL
Monomode
Multimode
//optional
OSI
The OSI model defines internetworking in terms of a vertical stack of seven layers. The upper
layers of the OSI model represent software that implements network services like encryption
and connection management. The lower layers of the OSI model implement more primitive,
hardware-oriented functions like routing, addressing, and flow control.
layers 7. Application Network process to application
6.Presentation Data representation and encryption
5. Session Interhost communication
4. Transport End-to-end connections and reliability
3. Network Path determination and logical addressing
2. Data Link Physical addressing (MAC & LLC)
Bit 1. Physical Media, signal and binary transmission
Network Hardware
Hub
classify as Layer 1 devices in the OSI model. At the physical layer, hubs can support little in
the way of sophisticated networking. Hubs do not read any of the data passing through them
and are not aware of their source or destination. Essentially, a hub simply receives incoming
packets, possibly amplifies the electrical signal, and broadcasts these packets out to all devices
on the network - including the one that originally sent the packet!
 passive
 active
 intelligent
Passive hubs do not amplify the electrical signal of incoming packets before broadcasting
them out to the network. Active hubs, on the other hand, do perform this amplification, as
does a different type of dedicated network device called a repeater. Some people use the terms
concentrator when referring to a passive hub and multiport repeater when referring to an
active hub.
Intelligent hubs add extra features to an active hub that are of particular importance to businesses.
An intelligent hub typically is stackable (built in such a way that multiple units can be placed one
on top of the other to conserve space). It also typically includes remote management capabilities via
SNMP and virtual LAN (VLAN) support.
Switch
it is network device that connects networksegments and computers.
Network switches appear nearly identical to network hubs, but a switch generally contains
more intelligence (and a slightly higher price tag) than a hub. Unlike hubs, network switches
are capable of inspecting data packets as they are received, determining the source and
destination device of each packet, and forwarding them appropriately. By delivering messages
only to the connected device intended, a network switch conserves network bandwidth and
offers generally better performance than a hub.


Unmanaged switches — These switches have no configuration interface or options.
They are "plug-and-play." They are typically the least expensive switches, found in
home, SOHO, or small businesses. They can be desktop or rack mounted.
Managed switches — These switches have one or more ways, or interfaces, to modify the
operation of the switch. Common management methods include: a serial console or
Command Line Interface accessed via telnet or Secure Shell; an embedded Simple Network
Management Protocol SNMP agent allowing management from a remote console or
management station; a web interface for management from a web browser. Examples of
configuration changes that one can do from a managed switch include: enable features such
as Spanning Tree Protocol; set port speed; create or modify VLANs, etc. Two sub-classes of
managed switches are marketed today:
switch layer (tabelle)
layer1 Hub
layer2 switch
layer3 switch switch with router functionality (descriotion on the next page)
layer4 switch with firewall, vpn functions
layer7 switch with a proxy
Router
A router (pronounced /'rautər/ in the USA, pronounced /'ru:tər/ in the UK and Ireland, or either
pronunciation in Australia and Canada) is a computer whose software and hardware are
usually tailored to the tasks of routing and forwarding information. For example on the
internet information gets routed to different places using routers.
Routers connect two or more logical subnets, which do not necessarily map one-to-one to the
physical interfaces of the router.[1] The term "layer 3 switch" often is used interchangeably with
router, but switch is a general term without a rigorous technical definition. In marketing usage, it is
generally optimized for Ethernet LAN interfaces and may not have other physical interface types. In
comparison a network hub does not do any routing, instead every packet it receives on one network
line gets forwarded to the other network lines.
Bridge
connect networks with a different media for example ehternet wlan
repeater ??
firewall ??