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Delivery and Routing of IP Packets
Oleh:Abdul Kholiq,S.Kom
www.abdkejora.wordpress.com
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Delivery
• Mean the physical forwarding of packet• Concepts :
– Connectionless and connection-oriented service– Direct and indirect delivery
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Connectionless vs Connection-oriented service
• Delivery is accomplish using either connectionless or connection-oriented service
• Connection-oriented:– Network layer protocol first establish connection– After that, a sequence of packets can be sent one after
another. – A packet is logically connected to the packet traveling
before it and to a packet traveling after it – When all packet have been delivered, the connection is
terminated– Route of a sequence of packet can be made only once,
when the connection is established.• Routers do not have to recalculated the route for each individual
packet
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• Connectionless– The network protocol treats each packet
independently, with each packet having no relationship to any other packet.
– Packets may not travel the same path to their destination
– IP protocol is a connectionless protocol. • It is designed this way because IP, as an internetwork
protocol, may have to deliver the packets through several heterogeneous network
• If IP were to be connection-oriented, all of networks in the internet should also be connection-oriented, which is not the case
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Direct versus Indirect Delivery
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Figure 6-1
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Figure 6-2
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Routing Methods• Next- Hop routing• Network-specific routing• Host-specific routing• Default routing
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Figure 4-3
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Figure 6-4
Network specific routing
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Figure 6-5
Host specific routing
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Figure 6-6
Default routing
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Static vs Dynamic Routing• Static routing table contains information entered manually
– ADM enters the route for each destination in table– When a table is created, it cannot update automatically when there is a
change in the internet– Can be used in a small internet or in an experimental internet for
troubleshooting
• Dynamics routing table – is updated periodically using one of the dynamic routing protocol such
a RIP, OSPF, or BGP– Whenever there is a change in the internet, such as shut down of a
routers or breaking of a link, the dynamic routing protocols update all of the tables in the routers (and eventually in the host)
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Figure 6-7
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Figure 6-8
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Figure 6-9