Lecture 6 (unfinished)

Question 1

What is the Internet?

Answer 1

Internet: Interconnected Network.

Question 2

What is a switch?

Answer 2

Switch
o It is the central component of a single physical network (e.g Ethernet LAN)
o It interconnects computers in a physical network and transfers frames between them

Question 3

What is a router?

Answer 3

• Router
o It Connects two or more networks and transmits the IP traffic between networks
o The networks can be heterogeneous => The format of the frames differ; (eg. Interface
Ethernet or 802.11)

Question 4

Types of networks in internet

Answer 4

Backbone
metropolitan network
cosmopolitan network
local area network

Question 5

What are backbones in terms of internet?

Answer 5

Backbones: Networks are used to interconnect other networks (e.g. WANs)

Question 6

What are commercial networks in terms of internet?

Answer 6

Commercial networks provide access to their subscribers in backbone networks

Question 7

What is ISOC?

Answer 7

It is a professional association that facilitates, promotes and supports the development of the Internet as a global communications system

Question 8

What is ICANN

Answer 8

ICANN is responsible for the management of IP addresses and DNS domains

Question 9

What is the Internet Architecture Board?

Answer 9

15 members

It serves as the final quality control council of Internet standards

Question 10

What is IRFT?

Answer 10

IRFT deals with long-term research programs

Question 11

What is IETF?

Internet Engineering Task Force

Answer 11

deals with the short-term creation of Internet standards

9 areas e.g. security

Question 12

Layers in TCP-IP Protocol Stack

Answer 12

Application
Transport
Network
Data Link
Physical

Question 13

Describe internet Protocol in terms of TCP-IP Layer?

Answer 13

Internet Protocol (IP)
o No guarantee if the packet will arrive
o Congestion may cause the routers due to limited buffer size
o When congested occurs, routers will drop the packets

Question 14

What is an IP host?

Answer 14

IP host: A device with ΙΡ address
e.g. Ethernet switch (L3)

Multiple hosts can be located either on a network or part of a subnet

Question 15

What are some IP layer Service Characteristics?

Answer 15

Connectionless service: There is no signaling establishment between sender and receiver

The IP Packet (Datagrams) vary in length

Best Effort Service
o Delay, out of sequence packets and manage losses from higher-layer protocols
o IP forwarding
o Using the routing tables

Provides reports for the transmission and delivery of IP Packet
o Using the protocol ICMP

Question 16

What do IP packets/datagram consist of ?

Answer 16

A header followed by Payload

o Payload from higher-level protocols (eg. TCP, UDP)

Question 17

Describe IP packets

Answer 17

IP packets are encapsulated within the physical network using a physical
network (e.g. Ethernet, WiFi)
Ethernet maximum length 1500 bytes
• Use of fragmentation and reassembly method for transmitting through
different networks maximum frame length

Question 18

What is Forwarding in terms of IP Routing?

Answer 18

Forwarding: Transfer packets from router’s input to appropriate output
(interface)

Question 19

What is Routing in terms of IP Routing

Answer 19

Routing: determine the route of packets from the sender to the recipient

Question 20

Maximum Transmission Unit formula?

Answer 20

Maximum Transmission Unit

o MTU = IP Datagram (data + header)

Question 21

What is multihoming in terms of IP Addressing?

Answer 21

Multihoming: When a host is connected to multiple networks and uses an IP address for each network

Question 22

How are IP Addresses defined

Answer 22

IETF RFC standard 1166