Question

1) Two key network layer functions are forwarding and routing.
What are forwarding and routing?
How does a router work ?

2) 1. Distinguish between the process of routing a packet from the source to the destination and the process of forwarding a packet at each router.
2. List four types of delays in a packet-switch network.

Answer 1

1) FORWARDING AND ROUTING:

FORWARDING:

It is a process occurring in Network Layer.

It is a process af moving a packet from the input port to the appropriate output port.

It is a process of getting through single interchange.

ROUTING:

It is also a process occurring in Network Layer.

It is a process of determining the end-to-end routes between sources and destinations.

It is a process of planning a trip from source to destination.

WORKING OF ROUTER:

A Router is a device that routes the traffic between the devices and the internet.It communicates between the internet and the devices which is in your home which are connected to internet network.

In a home, there will be a range of internet connected devices including,smartphones,tablets,smart TVs,personal computers.thermostats etc.This connected devices forms a network by the ROUTER.The incoming and outgoing internet traffic on network is enabled in most efficient and fastest way with the help of router.Router assigns a local IP address to each of the devices on the network.Routers connects with a modem like a fiber ,cable,or DSL modem to other devices for enabling communication between the devices and the internet.

2)  .PROCESS OF ROUTING A PACKET FROM SOURCE TO DESTINATION AND PACKET FORWARDING:

Routing is the process in which the system takes decision on where to send the packet.The system containing routing protocols discover the other system on the local network.In same local network,a source system and a destination system occurs,then the path in which packet  travel between them is called direct route.beyond the packet's source system, if a packet travel at least one hop beyond,then the path between the source and destination system is called as indirect route.In system's routing table ,the routing protocols learn the path to a destination interface and retain about known routes.

Packet forwarding is a process or a basic method for sharing information across systems over a network.The transferring of packets are done between the source interface and destination interface,which is on two different systems.when we send a message or issue a command to a non local interface,the system will forwards those packets on to the local network.the packets from the local network are retrieved when the interface with the destination IP address are specified in the packet headers.if the local network is not having the destination address ,then the packets will be forwarded to the adjacent network or the hop.the automatic configuration of packet forwarding is done usually when you install Oracle Solaris.

.In packet switched network,there are four types of delays:

. processing delay-it is the time needed to process a packet.

.queuing delay-it is the sum of delays which is encountered by the packet between the time of insertion into the network and delivery to address.

.transmission delay-it is the transmission rate pf an interface.

.propagation delay-it is the time taken for a signal to traverse the medium.