[NOTE: The Short answers are from Google so please check all the answers again.The correctness of answer is on your own risk.]
1. The function of transport layer are as follows:
- Communication with session layer and above.
- Reassemble transport protocol data units into data stream.
- Recover lost data.
- it is use for message error control and flow of control
2.The example of longest prefix matching rule is used while routing is;
When the address 192.168.20.19 needs to be looked up, both entries in the forwarding table “match”. That is, both entries contain the looked up address. In this case, the longest prefix of the candidate routes is 192.168.20.16/28, since its subnet mask (/28) is longer than the other entry’s mask (/16), making the route more specific.
3.The differences between TCP and UDP header are:
- TCP is connection oriented where as UDP is connection less .
- TCP is slower than UDP.
- Header size of UDP is 8 bytes where as TCP is more than double of UDP.
4. The link-state protocols is performed by every switching node in the network i.e. node that are prepared to forward packets; in the internet, these are called router.
6. Routing is the process of selecting a path for traffic in a network. or between or across multiple networks. Routing is performed in many types of networks such as internet, public switched telephone network.
7. Mechanism of sharing & exchanging packets/messages by a host(router) to group of targeted host only is define as multi-casting. Using these casting approach only specified range of destination host can receive the transmitted msg.
9.Virtual circuit is a means of transporting data over a packet switched computer network in such a way that it appears as though there is a dedicated physical layer link between the source and destination end system of this data.
10. A content distribution network is also known as a content delivery network. It is a geographically distributed network of specialized server that accelerate the delivery of web content and rich media to internet.
1. List the function of network layer?
- i. determination which router is suitable from source to destination.
- ii. Defines logical address or ip address.
- iii. It is responsible for encapsulating data ￼
2. List the issues of IPv4?
- Weak expansibility of the protocol
- problem of safety of communication.
- Deficiency of address space iv. Problem of renumbering of machines.
Q.1 List out the advantages of layered architecture.
The advantages are:
- Layered architecture enables develop loosely coupled systems
- Layered architecture also helps you to test the components independently of each other
- Layered architecture increases flexibility, maintainability, and scalability.
- Different componentsof the application can be independently deployed, maintained, and updated, on different time schedules
- Layered architectureenables teams to work on different parts of the application parallely with minimal dependencies on other teams
Simplicity: The concept of layered architecture is easy to learn and implement.
Consistency: The layers along with the overall code organization is consistent across all the layered projects.
Browsability: All the objects are kept together. So, when you need to change something in some or all the objects of a particular type, it is easier to quickly find an object.
Q.2 What do you mean by VCI?
VCI stands for Virtual Channel Identifier. A VCI is used in asynchronous transfer mode (ATM) cell networks. Each ATM cell header has a VCI, which is a 16-bit numeric field, for logical virtual channel identification. Each VCI works with a virtual path identifier (VPI) to facilitate end-to-end data packet transfer
A virtual channel identifier (VCI) distinguishes virtual channels (also known as circuits) created in a packet/cell switched network. A VCI has multiple circuits per communication channel and is primarily used for managing the unique identification of each created circuit. A VCI is also known as a virtual circuit identifier (VCI).
Q.4 Define load balancing.
Load balancing refers to efficiently distributing incoming network traffic across a group of backend servers, also known as a server farm or server pool. A load balancer acts as the “traffic cop” sitting in front of your servers and routing client requests across all servers capable of fulfilling those requests in a manner that maximizes speed and capacity utilization and ensures that no one server is overworked, which could degrade performance.
Q.5 What is the difference between IGMP version 2 and 3?
IGMP version 2 has “leave” mechanism i.e. hosts just stop listening to the multicast group address but they never report this to the router
IGMP version 3 adds support for “source filtering” i.e. we can join multicast groups but only from specified source addresses
Q.6 Define IS-IS
Intermediate System to Intermediate System (IS-IS, also written ISIS) is a routing protocol designed to move information efficiently within a computer network, a group of physically connected computers or similar devices. It accomplishes this by determining the best route for data through a packet-switched network.
The IS-IS (Intermediate System – Intermediate System) protocol is one of a family of IP Routing protocols, and is an Interior Gateway Protocol (IGP) for the Internet, used to distribute IP routing information throughout a single Autonomous System (AS) in an IP network.
IS-IS is a link-state routing protocol, which means that the routers exchange topology information with their nearest neighbors. The topology information is flooded throughout the AS, so that every router within the AS has a complete picture of the topology of the AS.
Q.7 What do you mean by tunneling?
Tunneling is a protocol that allows for the secure movement of data from one network to another. Tunneling involves allowing private network communications to be sent across a public network, such as the Internet, through a process called encapsulation. The encapsulation process allows for data packets to appear as though they are of a public nature to a public network when they are actually private data packets, allowing them to pass through unnoticed.
Q.8 Define HOL
Head-of-line blocking (HOL blocking) in computer networking is a performance-limiting phenomenon that occurs when a line of packets is held up by the first packet. Examples include input buffered network switches, out-of-order delivery and multiple requests in HTTP pipelining.
Q.9 What is the maximum and minimum size of IP packet that carries ICMP message?
Maximum 65535 bytes, Minimum 20 bytes
Q.10 Difference between unicasting, multicasting and broadcasting.
- Unicast: from one source to one destination i.e. One-to-One
- Broadcast: from one source to all possible destinations i.e. One-to-All
- Multicast: from one source to multiple destinations stating an interest in receiving the traffic i.e. One-to-Many
- What is IP aggregation?
Ans IP aggregation is used to summarize a number of subnets into one big supernet. It serves as a critical tool to reduce the size of routing table and helps reducing the processing power and memory usage of the router.
- Differentiate between static and dynamic routing.
Suitable for small networks
Suitable for large networks
Routes cannot be changed until authorized by network administrator
Routing protocols finds routes for traversing packets
Routers are not updated dynamically in routing table & hence cannot detect inactive routers
Routing table update routing table with updates routers
4.Define multi homing
Ans Multihoming is a mechanism used to configure one computer with more than one network interface and multiple IP addresses. It provides enhanced and reliable Internet connectivity without compromising efficient performance. The multihoming computer is known as the host and is directly or indirectly connected to more than one network.
5.What is jitter?
Ans Jitter is any deviation in, or displacement of, the signal pulses in a high-frequency digital signal. The deviation can be in terms of amplitude, phase timing or the width of the signal pulse. Among the causes of jitter are electromagnetic interference (EMI) and crosstalk with other signals.
- What is head of line blocking problem?
Ans Head-of-line blocking (HOL blocking) in computer networking is a performance-limiting phenomenon that occurs when a line of packets is held up by the first packet. Examples include input buffered network switches, out-of-order delivery and multiple requests in HTTP pipelining.
- What is IRC?
Ans Internet Relay Chat (IRC) is a system for chatting that involves a set of rules and conventions and client/server software. On the Web, certain sites such as Talk City or IRC networks such as the Undernet provide servers and help you download an IRC client to your PC.
1. Place the following protocols/mechanisms in the correct TCP/IP protocol layer. ICMP,DCCP,RTSP, and FTP.
FTP-Netowrk layer ICMP-Internet layer
RTSP-Transport layer DCCP- Transport layer
2. What is the aggregated network of the following subnets 126.96.36.199/26,188.8.131.52/26,184.108.40.206/26, 220.127.116.11/26
3. Define routing and forwarding.
Routing is the process of selecting a path for traffic in a network, or between or across multiple networks.
Forwarding refers to the router-local action of transferring the packet from an input link interface to the appropriate output link interface.
4. List the function of IQPOS
The functions are :- Shaping, admission control, scheduling, polishing
5. Why is playback buffer used ?
Playback buffer is used to store certain amount of the data before starting to play music or other media.
6. List the type of messages that ICMP protocol doesn’t report.
The types of messages are :-
- A datagram carrying another ICMP error.
- A datagram sent as link-layer broadcast
- Any ip fragment another than first.
- A datagram destined to IP broadcast or multicast.
1. Place the following protocols/mechanism in the correct tcp/ip layer: IGMP, STCP, DNS and RTP.
application layer- DNS
Transport layer- RTP
Internet layer- IGMP
2. Define delay and jitter.
Delay is defined as the end to end time required for the signal to travel from transmitter to receiver and Jitter is defined as the variation of delay for packets belonging to the same flow.
3. What are the basic features of STCP protocol?
it provides generic, scalable and reliable transport layer paradigm for sensor networks. It focuses on the sensor transmission requirements. It satisfies the requirements of constrained devices.
5. What is the fundamental differences between link state routing protocols and distance vector routing protocols.
The fundamental difference between distance vector and link state routing protocols is in the nature of the routing information routers send to each other.
In distance vector protocols, each router sends its neighbors a list of all known networks along with its own distance to each one of these networks.
In link state routing protocols, each router describes itself and its interfaces to its directly connected objects; these objects can be either neighboring adjacent routers, or they can be directly attached networks.
6. Explain “bring home” CDN policy.
It is a second design philosophy, taken by Limelight and many other
CDN companies, is to bring the ISPs home by building large clusters at a smaller number (for example, tens) of key locations and connecting these clusters using a private high-speed network.
7. Explain group shared tree multicasting.
Group-shared tree is a multicast group includes all the edge routers and hosts. Group-shared tree shares a single tree for all the hosts and initiate the multicast join.
8. Explain HOL blocking.
Head-of-line blocking (HOL blocking) in networking is a performance issue that occurs when a bunch of packets is blocked by the first packet in line. It can happen specially in input buffered network switches where out-of-order delivery of packets can occur. A switch can be composed of input buffered ports, output buffered ports and switch fabric.
- List the function of transport layer.
- Flow Control
- error control
- segmentation and reassembling messages.
2. Differentiate TCP and UDP headers.
– Connection oriented protocol
– Guaranteed message delivery
– Has 20 bytes header
– 3 way handshake
No message delivery guarantee
Has 8 bytes header
3. How do the link state protocols work in principle
Link state protocols work by having each node share its routing table with its neighbours. In a link-state protocol the only information passed between nodes is connectivity related.
4. Give the ipv6 address, AA00:E009:0000:0000:0FFE:1234:0000:0000, list the different ways the address can be shortened.
Ans. AA00:E009:0:0:0FFE:1234:: OR AA00:E009::0FFE:1234:0:0
Routing is the process of selecting a path for traffic in a network or in a multiple networks.
Multicast is group communication where data transmission is addressed to a group of destination computers simultaneously. Multicast can be one to many or many to many distribution.
7. Define playback buffer in Tcp streaming
When a session begins, the receiver delays playback and places incoming data in the buffer. When data in the buffer reaches a predetermined threshold, known as the playback point, output begins.
8.What are Virtual Circuits?
Ans. A virtual circuit is a means of transporting data over a packet switched computer network in such a way that it appears as though there is a dedicated physical layer link between the source and destination end systems of this data.
9.Define Content Distribution Network.
A content distribution network is a system of distributed servers (network) that deliver pages and other Web content to a user, based on the geographic locations of the user, the origin of the webpage and the content delivery server.
- Place the following protocol in the correct TCP/IP protocol layer: Ethernet, DCCP, ICMP, and HTTP.
Ans: Ethernet:- Network Interface Layer
DCCP:- Transport Layer
ICMP:- Internet Layer
HTTP:- Application Layer
2. The network 18.104.22.168/24 is split in half to create two subnets of equal size. Specify (in CIDR notation) the two resulting subnets.
Ans: The two resulting subnets is:22.214.171.124/25 and 126.96.36.199/25 .
3. What is the difference between a distance vector and a path vector ?
Ans: The difference between a distance vector and a path vector is:
It updates distances from neighbours distance.
It updates paths based on neighbours path.
It is slow due to count-to-infinity.
It is slow deu to path exploration.
RIP, EIGRP protocols use this types of routing vector.
BGP protocols use this type of routing vector.
4. What is BGP ?
BGP(Border Gateway Protocol) is a protocol that manage how packets are routed across the internet through the exchange of routing and relationship information between edge routers.
5. What are the differences between Multicast and Multiple unicast ?
Ans: The differences between Multicast and Multiple unicast is:
Multicast starts with one single packet from the source that is duplicated by the routers.
Multiple unicast starts with packets from the source.
The destination address in each packet is the same for all duplicates.
Destination address will be different in each packet.
6. List the name of the IPv4 header.
Ans: The name of the IPv4 header are listed below:
- Internet Header Length
- Type of service
- Total length
- Time to live
- Header Checksum
7.Why is RSVP described as a receiver-oriented protocol ?
Ans: RSVP is described as a receiver-oriented protocol because in RSVP the receiver describe the resource requirements in a flow specification it sends in a reservation message. This flow specification is forwaded in the direction of the sender.
8. Which technique is used in CDNs(Content Distribution Networks) to guide browsers to the correct server ?
Ans: DNS indirection technique is used in CDNs(Content Distribution Networks) to guide browsers to the correct server.
9. What does “torrent” mean in the context of BitTorrent ?
Ans: In the context of BitTorrent “torrent” is a computer file that contains meta-data about files and folders to be distributed and usually also a list of network location of trackers.
10. What is head of line blocking problem ?
Ans:The head of line blocking problem is a performance-limiting phenomenon that occurs when a line of packets is held up by the first packet in line. It can happens specially in input buffered network switches where out-of-order delivery of packets can occur.
- Define CDN.
A content distribution network is also known as content delivery network. It is a geographically distributed network of specialized server that accelerate the delivery of web content and rich media to internet.
- List the issues of IPv4.
- IPv4 on its own does not have any security feature. Data has to be encrypted with some other security application before being sent on the internet.
- Too large Routing table.
- Weak expansibility of the protocol.
3. Define Congestion.
When too many packets are presents in the subnet performance degrades this situation is called congestion. The effect of congestion is delays in delivery and loss of packets.
4. List the type of message that ICMP protocol does not support.
The types of message that ICMP protocol does not support are as follows:
- A datagram carrying another ICMP error.
- A datagram destination to IP broadcast or multicast address.
- A datagram sent as link-layer broadcast.
- An IP fragment other than first.
5.What is head of line blocking problem.
Head-of-line blocking (HOL blocking) in computer networking is a performance-limiting phenomenon that occurs when a line of packets is held up by the first packet.
6. Define routing.
Routing is defined as the process of selecting the best paths from a source to destination in a network.
7. What do you mean by hop by hop count.
The hop count refers to the number of intermediate devices through which data must pass between source and destination.
8. What is multihoming.
Multihoming is a mechanism used to configure one computer with more than one network interface and multiple IP addresses. It provides enhanced and reliable Internet connectivity without compromising efficient performance. The multihoming computer is known as the host and is directly or indirectly connected to more than one network.
9. List the difference between IPv4 and IPv6
32 bits (4bytes) Address length.
128bits (16bytes) address length.
Packets header are 20 bytes long.
Packets header are 40 bytes long but simple then IPv4.
Address types: unicast = one to one, multicast = one to many, broadcast = one to all.
Address types: unicast, multicast and anycast.