- How to transmit
any kind of
data in
Ethernet:
Note:
- You can transmit
any kind of
data
in the
data portion of
the Ethernet frame
- We will transmit an IP packet using an Ethernet frame !!!
- You can transmit
any kind of
data
in the
data portion of
the Ethernet frame
- How to
to transmit a
(logical network) IP packet:
- We put an
IP packet
inside the
data portion of
the Ethernet frame
Graphically:
- We put an
IP packet
inside the
data portion of
the Ethernet frame
- Encapsulation:
- Encapsulation =
transmission technique where an
entire packet of
a protocol A
(= Internet packet) is
carried inside a
packet of protocol B
(= Ethernet frame)
Graphically:
It's like a capsule:
- Encapsulation =
transmission technique where an
entire packet of
a protocol A
(= Internet packet) is
carried inside a
packet of protocol B
(= Ethernet frame)
- Real life
encapsulation:
the FedEx service
We can put a letter (= packet A) inside a FedEx envelop (= packet B)
- Scenario:
- Node A wants to
transmit a
message to
node D:
Notice:
- There are two (2) different node with the same physical address (D)
- Node A wants to
transmit a
message to
node D:
- Prelude:
- Each node is
assigned a
unique IP address:
- The router
contains
information (= routing table) on
where to
forward
IP packets:
- Each node is
assigned a
unique IP address:
- How the
logical network forward
packets:
- The messsage is
put inside an
IP packet with
- source IP address = IP1
- destination IP address = IP4
Graphically:
- The IP packet is
transmitted
inside a
Ethernet frame to the
router:
- The IP packet is
extracted from the
Ethernet frame:
- The router uses the
destination IP address to
find the
output port:
- Then
forwards the
IP packet
inside
another
Ethernet (or some other type) frame:
- The messsage is
put inside an
IP packet with