Internet Computing

1. NETWORK LAYER
Data Plane
Group No - 09

2. TABLE OF
CONTENTS
Overview of Network
Layer 01
02
04
05
What’s Inside a
Router?
The Internet
Protocol (IP)
Generalized
Forwarding and SDN

3. INTRODUCTION
Network Layer
• End To End Transport Process
• Addressing End Devices
• Encapsulation
• Routing
• De-Encapsulation
Internet Protocols
• IPv4
• IPv6

5. OVERVIEW OF
NETWORK LAYER
01

6. 01) OVERVIEW OF NETWORK LAYER
1. Forwarding and Routing: The Network Data and Control Planes
2. Network Service Models

7. 1.1) Forwarding and Routing:
The Network Data and Control Planes
Data Plane Control Plane
Network Layer
Forwarding (hardware)
Destination-based
Forwarding
Generalized
Forwarding
Routing Management
(software)

8. Routing
When a packet arrives at a router’s
input link, the router must move
the packet to the appropriate
output link. (Data Plane)
The network layer must determine the route
or path taken by packets as they flow
from a sender to a receiver.
(Control Plane)

9. 1.2) Network Service Models
The Network Service Model –
defines the characteristics of end-to-end delivery of packets between
sending and receiving hosts
1. Guaranteed delivery
2. Guaranteed delivery with bounded delay
3. In-order packet delivery.
4. Guaranteed minimal bandwidth.
5. Security

10. WHAT’S INSIDE A
ROUTER?
02

11. 02) WHAT’S INSIDE A ROUTER?
1. Input Port Processing and Destination-Based Forwarding
2. Switching
3. Output Port Processing
4. Where Does Queuing Occur?
5. Packet Scheduling

12. Input Ports
Switching Ports
Output Ports
Routing Processor
Two key router functions :
• Run function algorithms/protocols
(RIP,OSPF,BGP) – Control Plane
• Forwarding datagrams from incoming
to outgoing link – Data Plane

13. MARS
Output Port
Switching Fabric
Input Port

14. 2.1)
Input Port Processing and
Destination-Based Forwarding

15. 2.2)
Switching

16. 2.3)
Output Port Processing

17. 2.4)
Where Does Queuing
Occur?
Packet queues may form at both the input
ports and the output ports.
• Input queuing
• Output queuing

18. HOL Blocking
At the input port..
At the output port..
1) buffering
2) scheduling discipline
AQM
RED
RR
FIFO
Priority Scheduling
WFQ
2.5) Packet
Scheduling

19. THE INTERNET PROTOCOL (IP)
IPV4, ADDRESSING, IPV6
03

20. 03) THE INTERNET PROTOCOL
1. IPv4 Datagram Format
2. IPv4 Datagram Fragmentation
3. IPv4 Addressing
4. Network Address Translation (NAT)
5. IPv6

21. IP encapsulates the
transport layer segment.
• IP can use either an IPv4 or
IPv6 packet and not impact the
layer 4 segment.
• IP packet will be examined by
all layer 3 devices as it
traverses the network.
• The IP addressing does not
change from source to
destination.
MARS MERCURY VENUS

22. 3.1) IPv4 Datagram
Format

23. TABLE
3.2) IPv4 Datagram Fragmentation

24. Interface –
connection between host/router and physical link
Router - typically have multiple interfaces
Host - typically has one or two interfaces
IP address -
32 bit identifier for host , router , interface
3.3) IPv4 Addressing

25. IP addresses associated with each interface

26. Types of Addressing
Special Address
1. Host Address
2. Network Address
3. Broadcast Address
4. Loopback Address
Private Address
specific ranges of IP
addresses
1. Class A
2. Class B
3. Class C
4. Class D
Classful Addressing

27. CIDR Addressing
address format:
a.b.c.d/x, where x is # bits in subnet portion of address

28. Subnets
What ’ s a subnet ?
A network of device interfaces with same subnet part of IP address
Can physically reach each other without intervening router.

29. configured by system
admin in a file
Control panel-> Network
-> Configuration > tcp/ip->properties
DEC 10
Jupiter is the biggest
planet in our Solar
System
DHCP
Dynamic Host Configuration Protocol
dynamically get address from server
How to get an IP Address ?

30. 3.4) Network Address
Translation (NAT)
local network uses just one IP address as far as outside
world is concerned:
 can change addresses of devices in local network
without notifying outside world
 can change ISP without changing addresses of devices
in local network
 devices inside local net not explicitly addressable,
visible by outside world (a security plus)

32. 3.5) IPv6
Datagram Format Header Format

33. Ipv6 Features
• Longer address fields
• Simplified header format
• Flexible support for options
• Flow labeling capability
• Security
• Large packets
• Fragmentation at source only
• No checksum field

34. Ipv6 Addressing
• 128-bit addresses
• Includes network prefix and host suffix
• No address classes
• Three types of addresses:
Unicast addresses
Multicast addresses
Anycast addresses .

36. Transition from IPv4 to IPv6
• how will network operate with mixed IPv4 and IPv6
routers?
Tunneling:
IPv6 datagram carried as pay loading IPv4 datagram
among IPv4 routers

37. GENERALIZED
FORWARDING
AND SDN
04

38. 03) THE INTERNET PROTOCOL
1. Match
2. Action
3. OpenFlow Examples of Match-plus-action in Action

39. MATCH
Shows the eleven
packet-header fields
and the incoming port
ID that can be matched
in an OpenFlow
ACTION
Each flow table entry has a
list of zero or more actions
that determine the
processing that is to be
applied to a packet that
matches a flow table entry.
1. Forwarding
2. Dropping
3. Modify-field
OPENFLOW EXAMPLES OF
MATCH-PLUS-ACTION IN
ACTION
both the match and
action components of
generalized forwarding,
.

40. THANK YOU