Concepts of Layering · Computer Networks · GATE CSE

Consider a file of size 4 million bytes being transferred between two hosts connected via a path consisting of three consecutive links of bandwidth $2 \mathrm{Mbps}, 500 \mathrm{kbps}$, and 1 Mbps , respectively. All processing delays and propagation delays are negligible. Assume that there is no other background traffic over the path and no other additional overhead to transfer the file.

Which one of the following is the total time (in seconds) to transfer the file?

Note: $1 \mathrm{M}=10^6, 1 \mathrm{k}=10^3$

Consider the following statements :

(i) Address Resolution Protocol (ARP) provides a mapping from an IP address to the corresponding hardware (link-layer) address.

(ii) A single TCP segment from a sender $S$ to a receiver $R$ cannot carry both data from $S$ to $R$ and acknowledgement for a segment from $R$ to $S$.

Which ONE of the following is CORRECT?

Identify the ONE CORRECT matching between the OSI layers and their corresponding functionalities as shown.

	OSI Layers		Functionalities
(a)	Network layer	(I)	Packet routing
(b)	Transport layer	(II)	Framing and error handling
(c)	Datalink layer	(III)	Host to host communication

In the following pairs of OSI protocol layer/sub-layer and its functionality, the INCORRECT pair is

Assume that source S and destination D are connected through two intermediate routers labeled R. Determine how many times each packet has to visit the network layer and the data link layer during a transmission from S to D.

The protocol data unit (PDU) for the application layer in the Internet stack is

Which one of the following is not a client-server application?

Choose the best matching between Group 1 and Group 2 :

Group –1

P. Data link layer
Q. Network layer
R. Transport layer

Group – 2

1. Ensures reliable transport of data over a physical point-to-point link
2. Encodes/decodes data for physical transimission
3. Allows end-to-end communication between two processes
4. Routes data from one network node to the next

The forwarding table of a router is shown below.

Subnet Number	Subnet Mask	Interface ID
200.150.0.0	255.255.0.0	1
200.150.64.0	255.255.224.0	2
200.150.68.0	255.255.255.0	3
200.150.68.64	255.255.255.224	4
Default		0

A packet addressed to a destination address 200.150.68.118 arrives at the router. It will be forwarded to the interface with ID _______________.

Consider routing table of an organization's router shown below :

Subnet number	Subnet mask	Next hop
12.20.164.0	255.255.252.0	R1
12.20.170.0	255.255.254.0	R2
12.20.168.0	255.255.254.0	Interface 0
12.20.166.0	255.255.254.0	Interface 1
default		R3

Which of the following prefixes in CIDR notation can be collectively used to correctly aggregate all of the subnets in the routing table?