- Before the
IP protocol:
- There was a proliferation of network protocols interconnecting many different kinds of physical networks
- Goal of the
IP protocol:
- The IP protocol
was designed to
interconnect
any type of networks
I.e.:
- "One network to rule them (networks) all" :)
"Any type of network" would include even:
- physical network types developed in the future
How to achieve this goal:
- The IP protocol requires
very little capability of
the physical network.
- As long as the physical network can deliver a frame to the destination, the physical network can run the IP protocol !!!
- The IP protocol
was designed to
interconnect
any type of networks
- Case in point:
- The IP protocol
can even be and
in fact has been
implemented using
carrier pigeons:
click here
- The IP protocol
can even be and
in fact has been
implemented using
carrier pigeons:
click here
- Fact:
- There are 2 versions of
Internet Protocols in
existence today:
- IPv4 ("version 4")
- IPv6 ("version 6")
- There are 2 versions of
Internet Protocols in
existence today:
- IPv4:
- IPv4 was the
original IP protocol that
became well-known over the
world
- But due to its
popularity,
IPv4
was about to
run out of
IPv4 addresses
(IPv4 has 232 = 4 × 109 addresses)
- IPv4 was the
original IP protocol that
became well-known over the
world
- IPv6:
- IPv6 was
standardized in
1998
- IPv6 has 2128 = 3.4 × 1038 addresses !!!
- IPv6 was
standardized in
1998
- Fact:
- Most computers/routers today
have
both
IPv4 and
IPv6 in their
Operating System
- Such devices are known as dual stacked
- Most computers/routers today
have
both
IPv4 and
IPv6 in their
Operating System
- IPv4 addresses are officially
exhausted:
- IPv4 ran out of
addresses in
Sept 2015:
- IPv4 ran out of
addresses in
Sept 2015:
- Terminology:
- An IP packet is a datagram
- Properties of
a datagram:
- Unreliable delivery
- An IP packet can be lost (= not received by the receiver)
- No Acknowledgement
- The receiver does not acknowledge an IP packet when the packet is received
- Duplicate reception !!!
- The receiver can receive multiple copies of the same datagram !!!
- Unreliable delivery
- Services proviced by the
IP layer:
- The IP layer provides
similar transmission service as
the:
- Physical layer !!!!
Compare the IP datagram and a transmission in the physical layer:
- Both can be lost
- Neither requires ACKs (the Datalink layer uses ACKs, not the physical layer !!!)
- The IP layer provides
similar transmission service as
the:
- Difference between
the IP layer and
the physical layer:
- The physical layer
connects
two neighboring nodes:
- The IP (network) layer
connects
any two nodes:
- The physical layer
connects
two neighboring nodes:
- The reliable communication
function will be
implemented in the
next communication layer:
- The Datalink layer:
- uses the unreliable frame delivery service of the Physical layer to implement reliable communication between neighboring nodes
- The Transport layer (discussed later):
- will use the unreliable packet delivery service of the Network (IP) layer to implement reliable communication between any 2 nodes
- The Datalink layer: