Most Important Short Questions and Answered for Network Professionals


1-Define the following term:  Source Quench

Basically when data travels in form of packets from one node to another its transfer rate is usually fast & sometimes it’s too much for receiving end/server to handle so a message is generated from server to sender to reduce the speed of sending the packets that message is called Source Quench.


2-Define the following term:  De Facto Standard

De Facto Standards are those standards which can be retained by one or many or can be availed by everyone or just few.  They are based on “facts” basically anyone can control or manipulate them.


3-Define the following term: ARP Reply

Usually ARP is used to pinpoint Ethernet address when you have a desired IP to which you want to send data but you do not have an Ethernet address accompanying that IP. The sender sends an ARP Packet over the network all machines connected to it will receive it & whomever matches with the IP defined in the packet will send an acknowledgement & that message or acknowledgement is called ARP Reply which contains the MAC address of the desired device.

4-Define the following term: Soft State

It’s a signaling protocol which is basically a system composed of options or choices wherein the state is preserved probabilistically as cached info which is connected & from time to time refreshed by end hosts. After some time the unused stated results in time out from the router.


5-Define the following term: Internet Engineering Task Force (IETF)

The IETF is an international governing body of protocols that has only one goal to make internet improved & secured for everyone’s usage. They also define standard protocols like TCP/IP. In other words you can say IETF is a systematized movement of the Internet Society or ISOC which oversees this Task Force.

6-Briefly explain how ICMP and IP work together.

IP by itself has no function or rule that will sanction nodes to pass control messages over the network. As a substitute that function can be availed by an acquaintance protocol that works like an assistant to IP called the ICMP. While IP can focus on its basic tasks like addressing datagrams routing etc. ICMP offers vital support to IP via usage of control messages that will sanction nodes to pass messages or communicate over the network.

7-Explain in specific detail, the process that Jack’s computer will use to obtain the MAC address of Jill’s computer. The computers are using TCP/IP networking and are on the same local Ethernet network. Jack’s computer already knows the IP address of Jill’s computer.

Jack & Jill are connected & communicating over a same local Ethernet network & Jack’s computer already knows the IP address of Jill’s computer so using an ARP packet all over the network. Now an ARP request is used to pinpoint Ethernet address when you have a desired IP to which you want to send data but you do not have an Ethernet address accompanying that IP. Now the message from Jack’s Node is being broadcast to all nodes over that Ethernet Network that message contains Jill’s IP address & request an acknowledgement from a machine’s MAC address that matches Jill’s IP address. ARP Packet broadcasted over the network checks all machines connected to it & whomever matches with the IP defined in the packet will send an acknowledgement back to Jack’s computer & that message or acknowledgement will contains the MAC address of the desired device i.e. Jill’s Computer.

8-True or False: The destination IP address in an IP datagram header may not be changed under any circumstances by a router. TRUE

9-True or False: Jitter is a measure of delay. TRUE

10-true or False: If the first octet in an IPv4 fragment is the 3,468th octet of the unfragmented datagram the FRAGMENT OFFSET value for the fragment will be 0001110010000. FALSE

11-True or False: An intermediate router does not participate in direct delivery of a datagram. TRUE

12-True or False: The padding in an IP datagram, when used, is filled with binary zeros. TRUE

(Padding is used to be sure that IP Datagram ends on a 32 bit boundary. The padding stands zero.)

13-True or False: Encryption is not used to protect the contents of Voice Packets on Cable networks. FALSE

14-What 16-bit binary value would be placed in the PROTOCOL field of an ARP Request header when Ethernet and TCP/IP networking are being used?    [Provide 16 bits, no spaces, do not use the letter O instead of the number 0.]

2054 (hex 0806) for ARP datagrams. ARP Request Code will have Opcode = 1.

15-Compare the features of VoDSL and VoCable (not more than about 250 words)?

VoDSL uses the traditional DSL service via using copper wire arrangement for carrying voice. Unlike DSL can maintain several phone lines over a single subscriber line. Uses additional DSL bandwidth with dynamism. It’s more cost effective than VoCable. Protocols in VoDSL are more feasible than others. It’s also used in SME. It’s a service which is integrated, handles conversion of bandwidth & speculates for a growing market.

VoDSL and VoCable are two distinctions of packet-switching expertise both are connectionless and digital phone lines which are able to transport numerous voice signals over a sole twisted-pair of copper wire arrangement at a much lower cost than the traditional analog phone lines. But VoCable is a lot faster than VoDSL as it generates such an IP-based telephony experience that completely satisfies QoS that a user desires.

16-How might a source quenched sender recover from the resulting reduced transmission rate?

A source quenched server is obviously experience when the receiving end or host cannot buffer the data at this speed to it tells the sender to slow it down, the simplest act of our TCP operations is to lessen the amount or rate of exchange of data exceptional on network to host declared in Source Quench. This activity remains up until some number 10 in number normally of acknowledgments are collected and at that time TCP returns to normal operation & server starts towards recovery. Additional steps you can perform are checking that MTU amounts for Ethernet mostly that’s has value 1500; between your equipment equals. Check the link between the sites and routers which at times are unable to go on at the rate on which data is flowing.