Part_9_IP_Protocol

Part_9_IP_Protocol - Internet Protocol(IP The Network Layer...

Info iconThis preview shows pages 1–12. Sign up to view the full content.

View Full Document Right Arrow Icon
EE450, USC, Zahid 1 Internet Protocol (IP) “The” Network Layer EE450: Introduction to Computer Networks Professor A. Zahid
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EE450, USC, Zahid 2 Network layer in an Internetwork
Background image of page 2
EE450, USC, Zahid 3 Network Layer at Source/Router/Destination
Background image of page 3

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EE450, USC, Zahid 4 The IP Protocol
Background image of page 4
EE450, USC, Zahid 5 The Internet Protocol z IP is a connection-less, unreliable network layer protocol designed to be used in a connection-less (Datagram) packet switched network such as the Internet. z IP provides best effort services in the sense z There is no guarantee of delivery of error-free packets z There is no guarantee of ordered delivery of packets z There is no guarantee of delivery of packets, i.e. some packets may be lost, some packets may be duplicated z IP relies on upper layer transport protocols (TCP) to take care of these problems
Background image of page 5

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EE450, USC, Zahid 6 IP Packet Format
Background image of page 6
EE450, USC, Zahid 7 The Protocol Field z The protocol field (8-bits) defines the protocol that is using the services of IP. It defines the final destination protocol the packet should be delivered to. This is important since several protocols could be multiplexed over IP z ICMP : 1, IGMP: 2, TCP: 6, EGP: 8, UDP: 17, IPv6: 41, OSPF: 89, etc. ..
Background image of page 7

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EE450, USC, Zahid 8 Fragmentation z IP packet may travel over different networks (LANs and WANs) z A router de-capsulate an IP packet from the frame it receives, process it, and encapsulate it in another frame z Frame size and format varies depend on the data link protocol used by the physical network through which the frame is traveling z MTU (Maximum Transmission Unit) is the maximum size of the data field (payload) in the frame z If Packet size > MTU, Need for Fragmentation
Background image of page 8
EE450, USC, Zahid 9 MTU: Maximum Transfer Unit Protocol MTU (Octets) Ethernet 1500 Token Ring (4 Mbps) 4464 Token Ring (16 Mbps) 17914 FDDI 4352 X.25 576 PPP 296
Background image of page 9

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
EE450, USC, Zahid 10 Fragmentation (Continued) z Each fragment has its own header (most of fields are copied, some will change, including the total length, the Flags and the fragmentation offset fields) z A fragmented datagram may itself be fragmented if it encounters a network with smaller MTU z A packet can be fragmented by a source host or by any router in the path. Re-assembly of the packet must be done at the destination host because those fragments become independent packets and may travel different routes
Background image of page 10
EE450, USC, Zahid 11 Fragmentation and Reassembly z Network links have MTU (max.transfer size) - largest possible link-level frame. z Different link types, Different MTUs z large IP datagram “fragmented” within net z One datagram becomes several datagrams z “Reassembled” only at final destination z IP header bits used to identify, order related fragments fragmentation of one large packet into 3 smaller packets reassembly
Background image of page 11

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full Document Right Arrow Icon
Image of page 12
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Page1 / 36

Part_9_IP_Protocol - Internet Protocol(IP The Network Layer...

This preview shows document pages 1 - 12. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online