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Network Technologies
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NETWORK TRAINING (LAN)
Contents Networks: LAN, WAN Network Equipment Transmission PC Network Settings Confirmation of Connection
bcNetwork
LAN - WAN
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What is the Network ?Telephone network, TV network
Familiar and well-known network
Computer network Network connects computers and relative
devices One configuration is LAN which is selected
according to a system scale and connection.
Internet is one of the networks connecting over the world.
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What is LAN ?LAN: Local Area Network
It is a computer network in an enclosed zone, for example, a floor in a office, an office, a building, a complex
LAN
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Connection via LANStar Wiring
The most popular LAN is based on Ethernet using star connection. There are also other kinds of LANs based on other standards.
In this training, we just only explain about the star connection based on Ethernet.
LAN
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Ethernet NetworkAdvantages of an Ethernet Network
Ethernet protocol ubiquity Off-the-shelf functionality Standardised Hardware, Software &
Administration Tools Built-in routing features & extras
Filtering: converting data formats to match with media Bridging: connecting LANs Tree Spanning: construction of a virtual tree structure
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WAN (1)
WAN: Wide Area Network Well known: the Internet: public network VPN: Virtual Private Network: using public
communication lines (rented lines)
Connection to the WAN via DSL(Digital Subscriber Line)
Using analogue or ISDN telephone lines= 1 twisted pair
Transmission rate depends on distance to the next node
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WAN (2)
Unsymmetrical DSLs downstream data rate >> upstream data rate
ADSL (Asynchronous DSL) good for PC use (high download rate)
Symmetrical DSLs downstream data rate = upstream data rate
MDSL (Medium bit rate DSL), HDSL (High ..) connects company’s LANs, video conferences
SDSL (Symmetrical DSL) multi-media applications
VDSL (Very high bit rate DSL): new
bcNetwork
Equipment
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Network CableCable and Connector Type
CAT5 UTP cable with RJ-45 connector are used generally on 10BASE-T/100BASE-TX (Ethernet transmission speeds).
A cross cable is used between equipment or between repeater hubs
a straight cable is used between equipment and switching hub.
RJ-45 connectors
Network Technology: Equipment
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Cat5 Cable CAT5 UTP is an inexpensive
unshielded twisted pair data grade cable.
It is similar to telephone cable but the pairs are more tightly twisted.
Other CAT5 cables are the shielded STP or FTP types but
more expensive allow only short distances between
network devices Maximum UTP CAT5 cable length
between devices:100m (at 100MBps = 100Base-TX)
Network Technology: Equipment
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HUBDifferent HubsHubs connect network devices to each other. So network devices communicate via Hubs. HUB = Repeater HUB SWITCH = Switching HUB
Network Technology: Equipment
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Causing high data traffic because covering all lines
Repeater Hub Repeater Hub
MAC MACMACMAC
Repeater HubTransmits Data to All Nodes (Devices) on the Network
Only one transmitter can access the media at a given time
Only Half Duplex modepossible, because data collusion appears when transmitting from more than one device data drops
All agents must have the same transmission rate (10 or 100 Mb/s)
Network Technology: Equipment
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MAC
Ethernet Switch
MAC
MAC
MAC
Transmits data only to the receiver after confirmation of the receiver’s (MAC) address (selected signal path)
Switch (Switching Hub) (1)
Separate Paths
Independent full duplex paths can exist (simultaneous transmission)
Switches allow a virtual and intelligent routing of Ethernet packets
Agents can have different speeds Layer-3-switches analyze transmitter’s and receiver’s IP addresses and try to switch
all following frames
Network Technology: Equipment
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Switch (2)Spanning Tree (IEEE 802.1D)
Switch
Switch
Switch
before auto-configuration
Switch
Switch
Switch
after auto-configuration
Switch
Switch
Switch
looploop in case of failure
re-activation
The spanning tree function constructs an internal virtual tree structure between switches to
obtain best network properties avoid loops re-activating of de-activated signal paths
deactivated
Network Technology: Equipment
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Switch (3)
VLAN = Virtual LAN
VLAN 1 Switch
N-8000MI
N-8500
N-8000EX N-8500
N-8000EX
VLAN 2
If several applications shall be used in a LAN, then the virtual LAN feature can separate these applications virtually to provide best performance within each VLAN
Network Technology: Equipment
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Switch (4)
Unicast/Multicast Transmission to several receivers
Unicast: sending several of the same data packages to every receiver, i.e. sender must have high transmission rate
Multicast: sending the data packages once but with several destination addresses, and the Switch multiplies it to each receiver
Switch Switch
Data package with addresses of 3 receivers
Network Technology: Equipment
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Recommendations on Hubs for N-8000 Repeater hub must not be used use Switch!
Full duplex operation Support of spanning tree Automatic negotiation of transmission speed and mode
(IEEE802.3u (100BASE-TX) / IEEE802.3 (10BASE-T) standard) Multicast is supported by IGMP
(Internet Group Management Protocol)
Use QoS (Quality of Service = for real-time audio transmission) equipment as much as possible in a route.
Select VLAN feature when using same LAN for Packet Intercom and PCs
IP stations can be powered by Switches with PoE (power over Ethernet) feature
Network Technology: Equipment
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Networks with Switches
N-8000EX
N-8500
Switch
N-8500 N-8500
Switch
N-8000EX
N-8000EX
N-8000EX
N-8000MISwitch
N-8000EX
N-8000MIN-8000EX
N-8500
Switch
2nd line is spare line
within 100m
within 100m
within 100mwithin 100m
severalN-8000EX
Switch
in rack
severalN-8000EX
Switch
in rack
max
. 100
m
max. 100m
max. 100m
max. 100m
max. 100m
max. 100mhigh data traffic: 2 lines
Network Technology: Equipment
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Network Technology: Equipment
WAN Router with NAT/NAPTGeneral
Shares the Internet connection into several devices
Shares a global IP address for several devices
NAT: Network Address Translation Translates a global IP address into a
private IP address but: only 1 user can access the Internet at
a time
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Network Technology: Equipment
WAN Router with NAPT (1)
NAPT: Network Address Port Translation Translates a global IP address and port no. into a
private IP address and port no. (IP masquerade) Several users can access the Internet simultaneously
(session; max. no. of sessions!) Usually it uses a dynamic routing table but this is not
suitable for the N-8000 system N-8000 communicates with acknowledge signals. When
using a dynamic routing table, then the acknowledge signal may not be sent back to the correct receiver
Therefore it is necessary to use fixed private port no. which can be set by the N-8000 software
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WAN Router with NAPT (2)
Function of NAPT
Router213.191.74.18 3000
213.191.74.18 3001
3000 :192.168.0.1 23543001 :192.168.0.2 5832
::
192.168.0.1 2354
192.168.0.2 5832
Sender
Network Technology: Equipment
Receiver
192.168.0.1 2354
192.168.0.2 5832
Router213.191.74.18 3000
213.191.74.18 3001
bcTransmission
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Data Rate (Throughput)Official Data Rate
Means the capacity of how many data can be transmitted per second.
The data rate is mentioned as bps (bit per second).
Sometimes it is called forward speed or line capacity.
Effective Data Rate Means the actual capacity of which the data is transmitted.
In the LAN, the real transmission rate is 60-80% less. (Besides, around half of the rate in case of half duplex)
Network Technology: Transmission
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Ethernet Protocol
• Assumes a given transfer media:
the standardized Ethernet network
• Ethernet Packet Structure:
Dest. Addr. Source Addr. P FCSPayload
6 6 2 46-1500 4
EthernetLAN
EthernetLAN
ProtocolsEthernet Protocol vs Internet Protocol
Network Technology: Transmission
Internet Protocol• Makes no assumption on the transfer media
• Allows transfers across any media & jumps from one media to the other (via bridges)
EthernetLAN
EthernetLAN
ATMATM
EthernetLAN
EthernetLAN
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IP AddressWhat is an IP Address?
IP address means just the address of the node (device):
An IP address of a LAN (such as in an office) is assigned by a network administrator.
An IP address of the Internet, so called “Global IP Address”, is assigned by an Internet provider
Network Technology: Transmission
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Composition of the IP AddressThe IP address consists of 4 Bytes, divided into
Host address Subnet address
Example: 192.168.1. 3/24
Example:
A slash after the IP address indicates how many bits belong to the subnet address. The remaining bits belong to the host address.
1 1 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 1 1bits (binary)
192 168 1 3Bytes
192.168.1. 3written
Network Technology: Transmission
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Example: IP address ”192.168.1. 3“ but…
Subnet mask Network address(Subnet) Host address 255.255.255. 0 192.168. 1 3 255.255. 0. 0 192.168 1.3 255. 0. 0. 0 192 168.1.3
The above three setting mean: All nodes belong to a different subnet. *Examples 192.168.1.3/24, 192.168.1.3/16, 192.168.1.3/8
Subnet MaskA subnet mask is a parameter that divides the IP address into
the subnet (local network) to which the node belongs to
the host address of the node in the subnet.
Network Technology: Transmission
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Default GatewayTransmitting Data to other Network
When the data shall be transmitted to a node of an other subnet, then it will be forwarded to the node called Gateway in the network.
When the data is not send to a known node in the subnet, then the data is transmitted to the node called Default gateway.
The default gateway (in almost all cases it is a router) can route the data to communicate properly, if the default gateway is set in every nodes.
Network Technology: Transmission
bcSettings
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Windows2000Windows XP
Network setting on PC (1)
Select Properties in My Network Places
Network Technology: Settings
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Windows XP
Windows2000
Network setting on PC (2)
Select Properties in Local Area Connection
Network Technology: Settings
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Network setting on PC (3)
Select Properties in Internet Protocol(TCP/IP)
Windows2000Windows XP
Network Technology: Settings
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Network setting on PC (4)
Change the setting after note the current setting.
Windows2000Windows XP
Network Technology: Settings
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Proxy server setting (1)Select Properties of Internet Explorer
Click the tagfor Connections
Network Technology: Settings
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* CautionDon’t change other topics.Reset after use.
Proxy server setting (2)Select the LAN Setting
Uncheck after note the number of Address and Port
Network Technology: Settings
bcConfirmation
of Connection
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Echo requirement
Echo response
Please respond
Hello
Confirmation of Connection Link LED (normal: green) Ping (confirmation of IP communication)
When a ping is activated on a PC, then the data called echo requirement is transmitted to the other nodes.
When the activation of ping was successful, then it was confirmed that the PC and the node can communicate with IP packets.
The node who received the echo requirement transmits the echo response to the PC
Network Technology: Confirmation