Questions tagged [computer-networks]
Questions about problems that arise when you connect multiple computers to form a network.
340
questions
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Method for minimizing relays in a switching/steering network - combinatorics/CSP algorithm exists?
This question is borne from the electrical engineering world, so I first asked it there, but it's really more of an algorithm optimization problem that everyone here might be better suited to help ...
0
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1answer
32 views
Introductory books on Computer Networks
While I have come to learn some computer science, I find that I have next to no knowledge on computer networks.
Are there any good books at a basic level that cover some of the fundamental topics? ...
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0answers
10 views
What are the chances of fusing a quantum computer and a parallel computer and what potential dangers/ benefits does it bring?
From my EPQ research I came to know that quantum computers require certain conditions to function optimally such as: low temperature so that electrons do not get disturbed etc. I've also read a book ...
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1answer
18 views
internal DNS not resolving for a single, specific website
Our internal DNS servers (2019 standard) are setup without forwarders or conditional forwarders. Each server is set as its own IP address as its DNS server as well. We have no problems browsing to any ...
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0answers
19 views
Go back n on server side
I am implementing a UDP based go back n example and I am a bit stuck on how the server should respond to packets.
If my client has a sliding window of say 5, it can send 5 packets to the server ...
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0answers
18 views
A Networking Question
Please consider the following multiple choice question about computer networking. The question from the following website:
The Website that the question came from
Question:
Consider sending a 1300 ...
2
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0answers
44 views
questions about queuing delay
I am learning computer network, and confused by the queuing delay. In my textbook, it says that when La/R approaches 1, and with random inter-arrival times, then the average queuing delay is closer to ...
0
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0answers
12 views
The size of a router's forwarding table
Consider a home network. Say three computers, a network printer and an internet connection. The three computers and the network printer will use the router to communicate with each
other.
I am ...
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0answers
19 views
Trying to understand a Router's Forwarding Table
I am trying to understand how a router's forward table works. As such, I am working
on the following problem.
Problem:
A router’s forwarding table has the following entries.
\begin{array} {|r|r|}\...
3
votes
1answer
193 views
If the probability of frame being lost is $P.$ Then, calculate the mean no. of transmission for the frame to make it success$.$ [closed]
Here the probability of frame being lost is $P.$ So the probability of frame reaching safely would be $(1-P).$
Now lets consider that the frame will reach safely in $k$-th transmission. That means ...
2
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0answers
39 views
How probability P is chosen in P-persistent CSMA? [closed]
I am struggling to understand how the probability value P is chosen for P-persistent CSMA for any particular station, what's the logic behind this.I have read from Wikipedia .
P-persistent
This ...
1
vote
1answer
23 views
How does concept of "redirection" works in ICMP?
I am trying to understand this figure, what it is trying to say?
What I already know?
Routing table is updated dynamically. However, for efficiency, hosts do not take part in the routing update ...
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0answers
18 views
Why does diskless system doesn't contain IP address?
I am studying about RARP.
What is the IP address of a given hardware address? Used by diskless systems to find their own IP address.
https://www.cse.wustl.edu/~jain/bnr/ftp/f15_arp.pdf
So, why do ...
0
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0answers
35 views
How much byte do we need to record the route taken by a packet?
I am studying about IPV4 header.
For some options, such as one that records route a packet has taken, 40 bytes is far too small, making that option useless.
What does this mean?
What I know?
IHL ...
2
votes
1answer
34 views
Name for scheme and host of URL
Is there a specific name when we refer to just the scheme and host of URL, for example http://localhost of the URL ...
1
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0answers
274 views
How is this example sequentially consistent but not linearizable?
Background information that I know(But not understand with examples, I will be glad if you could explain it to me with examples)
A replicated service is said to be linearizable if for any executin ...
0
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0answers
15 views
Is ordering achieved by central server algorithm?
ME3 specifies that the first process be granted access before the second
Ordering-: Requests are granted in the order they were requested.
Colouris Distributed Systems book-:
The reader should ...
0
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0answers
15 views
Clock synchronization in distributed system-What is this slide trying to say?
For over an hour I am trying to decode this slide.
When each machine has its own clock, an event that occurred after another
event may nevertheless be assigned an earlier time.
Here event output.o ...
1
vote
0answers
11 views
Distributed Graph Consensus to fit a distribution?
$G$ is a strongly connected graph with nodes $V$ and edges $E$. Each node $v_i$ receives a sample $x_i$ from a Gaussian $\mathcal{N}(\mu,\sigma^2)$ with unknown mean and variance.
The objective is for ...
1
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0answers
69 views
How is this example related to Lamport clock theory? I can't relate algorithm example with the algorithm theory. Share some insights please [closed]
I have asked 1 type of question but I have asked that in many questions. So bear with me. My question is about 1 topic, I just didn't find it right to create separate questions for each of these ...
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1answer
36 views
If primary server's UTC source fails, how will synchronization be possible in NTP(network time protocol)?
If a primary server's UTC source fails, then it can become a stratum 2 secondary server. If a secondary server's normal source of synchronization fails or becomes unreachable, then it may synchronize ...
0
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0answers
37 views
What is the difference between content type and content description in MIME header?
I am following article which says-:
Content type-: defines the data present in body of message. eg-: text,image,video,application etc.
Content description-: It is used when body of message can't be ...
0
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1answer
38 views
Which overhead is smaller - function call or passing variables between processes?
the question is related to networking frameworks; callback-based approach requires you to call a callback function every time you receive a new data packet; this is not a good approach for high-load ...
1
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0answers
22 views
How does AH header in IPSec prevents replay attacks?
According to Tanenbaum's Modern operating systems,
The purpose of this field is to detect replay attacks. These sequence numbers may not wrap around. If all $2^{32}$ are exhausted, a new security ...
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2answers
53 views
How to solve modulo math equation in RSA algorithm?
$(3 \cdot d) \mod 8=1$. I know the answer is $d=3$ by common sense. But what is the mathematical approach to solve this problem? How do I solve this mathematically?
How do we get this value of 125^107 ...
3
votes
4answers
381 views
Why is TCP known as reliable protocol?
Is it because it uses 3 way handshaking, it is reliable? Or is it due to other reasons? Like due to congestion control, flow control and error control in TCP? Why do we call TCP as reliable?
0
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1answer
34 views
How many /20-subnets are in the network 130.149.0.0/16?
I'm new to networking so please bear with me. My textbook gives 4 as an answer, but I'm not sure I understand the question:
What's a "/20-subnet"? My understanding is that a network mask (/...
0
votes
3answers
40 views
Mutual Friends in a Network?
I always seem to have trouble finding a formal way to analyze this (be through proofs or whatever).
The problem statement is as such:
If A and B are friends, and B and C are friends, then A and C are ...
2
votes
0answers
33 views
Reference request on computer networks
I read about correctness of iterative and recursive algorithms.I need a sequence of book recommendations for learning mathematical aspects of computer networks and data communtions such as ...
0
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0answers
11 views
What are Cloud Infrastructure & Sevices, Distributed Computer Systems, and Internet-of-Things (IOT) Concepts and Applications?
I'm looking for experts to explain these Computer Science subjects that I have to choose in my university. Currently, it seems that IOT and Cloud Infrastructure are quite popular. What are their ...
0
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0answers
19 views
Can you ELI5 what makes it that people retain control over their data stored in SOLID servers?
Please, note that I'm not a dev and I'm not sure this is the right stackexchange, but really would like to understand this one.
So, I've recently discovered the SOLID project:
https://solidproject.org/...
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0answers
11 views
Encoding with Differential Manchester
I am trying to understand how encoding is done with differential Manchester, if you have a binary string, for example 10000000011010100010, how would we encode it?
or would I need more information to ...
2
votes
1answer
45 views
How does asynchronous operations save time in I/O
I'm reading a book CLR via C# which says how Windows does asynchronous I/O:
To read data from the file, ReadAsync internally allocates a Task object to represent the pending completion of the read ...
0
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0answers
10 views
While considering the wrap around time, why are the headers not considered?
In many texts and places as in here the wrap around time is found as :
$$\text{Wrap-Around Time = $\frac{2^{32} \text{ bytes}}{\text{Bandwidth in Bytes/sec}}$} $$
The wrap-around time is defined as ...
0
votes
1answer
52 views
What is the actual formula for the efficiency in CSMA/CD?
Let there are $n$ devices in the setup. Let each device sends data with a probability $p$.
Successful transmission for a slot (hence of the setup in general) occurs when only one device communicates.
...
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0answers
29 views
Confusion about the definition of "Exponential Average"
I was having doubt regarding the concept of "exponential averaging". Till now I have come across the concept twice and they seem to be quite similar (except that they have minor but sharp ...
1
vote
1answer
35 views
What is the difference between broadcast and gossip/epidemics?
Everything is in the title.
What is the difference between broadcast and gossip in the context of message-passing distributed systems?
According to Wikipedia, gossip and epidemic protocols/epidemics ...
1
vote
1answer
35 views
Can synchronous data transfer be used for transferring large data in case of computer architecture and organization?
I am learning computer architecture and organization.
I have this confusion, can synchronous data transfer be used for transferring large data in case of computer architecture and organization?
I ...
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0answers
17 views
Why does the author say that the sender in GBN protocol resends packet n to N(window size) when ack for packet n gets lost?
I was reading about the comparison of TCP with GBN protocol and I came across this text in the book Computer Networks: A Top Down Approach, 6th Edition by Jim Kurose on page 249;
Consider also what ...
1
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0answers
34 views
Is e-mail communication peer-to-peer?
In his networking textbook, the world-renowned computer science expert Tanenbaum says that e-mail communication is inherently peer-to-peer. Here is the paragraph from the book:
Peer-to-peer ...
1
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0answers
31 views
Tearing down the FSM description of congestion control
I was going through the text Computer Networking- A Top-Down Approach by Kurose and Ross, there I found subtleties with the TCP congestion control FSM which is shown below:
Mainly I am having ...
0
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0answers
15 views
Is peer to peer and client-server a type of network or protocol?
Is peer to peer and client-server a type of network or protocol? Because my book mentions this under types of network heading under the subsection of "Types of network on the basis of component ...
2
votes
0answers
18 views
How to use butterfly network for data copy?
I know butterfly networks (and benes as well) allow routing a packet from any input to any output node. Congestion is $\sqrt{n}$ but with bene it can be $1$.
Now assume that in a butterfly network, ...
1
vote
0answers
11 views
About the paper Privacy-preserving in association rule mining using an improved discrete binary artificial bee colony
I don't understand two parts in this paper:
The min notion on page 4 line 357 (equation 10d): I understand this as to find all the $M_{10}$, $M_{11}$, $M_{01}$ first and then try to minimize the ...
0
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0answers
19 views
Problem on probability given frame sizes and their error correction probabilities in a wireless system
I am stuck trying to solve the following question for a while
Bit error rate after demodulation in an wireless system = 1.0e-03.
The system has 4 possible frame sizes – 48 bytes, 96 bytes, 72 bytes
...
0
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1answer
26 views
How to reconcile the different definitions of asynchrony?
There are 3 definitions of asynchrony that I know of:
In event-based programming, asynchrony refers to the execution of tasks in a non-sequential way, which may involve creating another thread. For ...
0
votes
1answer
19 views
multicasting in ethernet
I am learning this topic and there is a concept that LSB ( bit ) of MSB ( byte ) should be set to 1 for multicasting . But why we need to do so as multicast address is unique so why can't we assign ...
0
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0answers
14 views
What are overlay & underlaying topologies in DHT?
We are covering Distributed Hash Tables in my "Networks" class and one of the subsections is about the improvements that can be made to increase the performance of the chord. Here, the ...
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0answers
17 views
Storing Network Packets in Tabular Form
For network packets coming over TCP/IP protocol, have you ever confronted a situation where you need to store those network packets in tabular form similar to how tabular tables in databases? For ...
0
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2answers
115 views
How a 10GB network can copy 1TB data in 2 hours?
In the slides of a university lecture, the following phrase got my attention.
Assuming 10GB network, it takes 2 hours to copy 1TB.
My calculation was as follows.
10GB network = 10 gigabits per ...
