Questions about problems that arise when you connect multiple computers to form a network.

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0answers
6 views

How do I scan for and discover active IPv6 addresses of devices behind a router? [migrated]

Usually with IPv4 and NAT you can only access a device behind a router if the router is port-forwarded correctly or is the router's DMZ. When behind the router you can easily scan for the IPs behind ...
0
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0answers
23 views

How http response propagated [closed]

As much as I understand, when we hit an url in browser, it reaches a server in a complex path, but as a web developer, when we check the data in the request, we don't see the client IP there. So how ...
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0answers
18 views

Bit Stuffing Conversion to original string

Looking at a past exam paper it has the following question; The following sequence was transmitted using the stuffing bit protocol ...
1
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0answers
12 views

Byte Stuffing, escaping a flag at maximum frame

I want to encode a message using byte stuffing where every frame delimited by a flag byte 'F' at both ends and escape code equal to the character E. I am trying to encode the message ...
1
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0answers
13 views

Throughput in sliding window protocol

Can anyone help me with this test question ? I am not really expert on this. Assume $1000$BASE-LX network. Communication is using sliding window protocol with $15$ frames, each frame with $1000$ ...
0
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1answer
36 views

Difference between centralized computing and distributed computing using Client-Server

I already understand that Distributed Computing is the breakup of having multiple clients rely on a single source, and having each client utilize other clients for information. But my confusion comes ...
2
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2answers
46 views

When is an ATM network connection superior to an IP connection?

Currently learning about Networks in Computer Science, and I don't understand why you would ever use an ATM (asynchronous transfer mode) network instead of IP, as IP doesn't have to be as reliable ...
0
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1answer
58 views

What is the difference between centralised, decentralised, distributed, fully-distributed?

What is the difference between centralised, decentralised, distributed, fully-distributed, partially-centralised, partially-decentralised system? Which type or topology is the system attached in the ...
1
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0answers
30 views

How Can a Network Server Identify a Specific Computer, Is There a Computer Fingerprint?

Most of websites put some restrictions on how to use their services; the following paragraphs are taken from “Terms of Service” of such website: Only one account per computer is allowed to view ads. ...
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0answers
16 views

TCP Reno and RTT bandwidth

Is it possible for TCP Reno to reach a state with the congestion window size much larger than (e.g., twice as large as) RTT bandwidth? Is it likely?
2
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1answer
44 views

What exactly would stop me from registering a domain from my own nameserver? [closed]

Can I just make a nameserver and claim away? Are there implemented measures to stop this from happening?
1
vote
1answer
16 views

Resending old frame when a damaged frame has been received in one bit sliding window protocol

I'm reading Tanenbaum's and Wheterall's book on Computer Networks. I'm trying out some examples of situations that can occur in the one bit sliding window protocol for a datalink layer. The code for ...
1
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2answers
37 views

What is the difference between transmission delay, queuing delay, and processing delay?

My book defines queuing delay as the time the packet waits to be transmitted onto the link. It defines transmission delay as the amount of time required to push all of the packet's bits onto the link. ...
0
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0answers
15 views

Calculating routing protocol overhead

Do you know how to calculate the % Overhead of routing for RIP and OSPF? I know that: for RIP, the total overhead= rate of routing update * no. of nodes * average length of RIP packet Then the ...
0
votes
1answer
40 views

Difference between 2f+1, 2f and 3f+1

I am currently reading the Practical Byzantine Fault Tolerance paper. I am unable to completely understand the difference between 2f and ...
4
votes
1answer
92 views

How internet speed is manipulated at the physical level

Although I am a computer science major, I am having a hard time understanding how internet providers have control over internet speed (example: offer different speeds to different customers, one with ...
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votes
1answer
38 views

client and server programs [closed]

I\’m a novice programmer that\’s learning how to program on his own currently. I\’m currently fiddling around with a server/client program that allows me to send a signal from one computer to another. ...
0
votes
1answer
17 views

In the Data Link Layer, is it better to use large or small frames?

I understand how the layer works to an extent, but cannot seem to figure out if the data link handles big frames more efficiently due to error detection or small frames better. I am assuming from my ...
0
votes
1answer
20 views

Class C can have _______ 1s with the remaining bits 0s [closed]

A subnet mask in class C can have _______ 1s with the remaining bits 0s. MyApproach: Class C subnet is 255.255.255.0.So, accordingly it has 9 1s on first byte,9 1s on second byte and 9 1s on ...
2
votes
1answer
43 views

How does the Weibull distribution work as fault model in wireless sensor networks?

I am a little bit confused with the concept of using the Weibull distribution or other distribution for fault model. As I understand, in simulation this distribution is often used for modelling a ...
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votes
1answer
29 views

How does MAC layer back-off work?

How does it help avoid frame collisions? Are there any rules for when the back off is allowed, especially in the case of wireless networks?
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1answer
46 views

How would I add 0.0.15.255. to 172.1.6.255.? [closed]

How would I add 0.0.15.255 to 172.1.6.255, talking about IPv4 networks here. I have done things like 192.168.1.15 plus 0.0.1.30 to be 192.168.2.45. but when it goes over the limit of 255, I just do ...
4
votes
1answer
56 views

How can I calculate optimal batch sizes for calls to an external server?

So I have a large number of commands, say 500,000, that I want to send and run on a server somewhere else, and get the answers back. All of these commands together takes a long time to execute - ...
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votes
1answer
49 views

Why can't you see computer behind a router?

I understand the basics of networking(DNS,DHCP,IP,MAC, etc.). I have installed a router and plugged my computer into the router. On the other end of the router the cable goes somewhere to a switch(I ...
0
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2answers
35 views

Is it possible to calculate the propagation delay if only the length of the link is known & not the speed at which a bit travels into the link?

Consider a $10^7$ bps link that is $400$ km long, with a queue large enough to hold $2000$ packets.Assume that the packets arrive at the queue with an average rate of $4000$ packets per second ...
2
votes
1answer
50 views

Why arrival process of packets at a switch is not a Poisson Process?

"Packet arrivals are not Poisson .... but some events are, such as web requests and new flow arrivals" I know since the network traffic is very bursty, they are not Poisson. But I am unable to ...
2
votes
1answer
39 views

Term for shifting work to idle machines

I am looking for a term here. A while ago, i was told about a network in which all the computers are connected in parallel, and when a computer is idle, the central server sends heavy cpu usage tasks ...
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0answers
40 views

Counting hops in a network when broadcasting

Given the below network, how many hops are required to broadcast a message from one router to all others using: a. reverse-path forwarding b. a sink tree for the source router c. sequence number ...
2
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0answers
15 views

Benes (Fat Tree) Network for number of inputs/outputs that is not 2^n

I was reading about Benes Network construction in this book. Their construction is easy for a number of inputs and outputs that is an exponent of two. However it seems to me that for a number of i/o ...
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votes
1answer
37 views

Do iterative DNS queries return results from the servers cache?

So if i only used iterative requests to a recursive dns server and since this server has cached results from recursive queries, does this mean the iterative request gets a result from the cache or ...
1
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1answer
72 views

What this subnetting restriction means

I was reading Data Communication book by Forouzan in which there is a one restriction put on CIDR subnetting by Internet authorities: First IP address in the block should be evenly divisible by ...
3
votes
1answer
60 views

Algorithm for executing a command against a million hosts

Consider the following problem: you are given a set of one million machines (hosts), and you would like to have the ability to execute at will an arbitrary command against the whole set; for the ...
41
votes
4answers
3k views

Why are so many internet protocols text-based?

From what I have found, a very large amount of protocols that travel over the internet are "text-based" rather than binary. The protocols in question include, but are not limited to HTTP, SMTP, FTP (I ...
2
votes
2answers
171 views

Hamming code — identical parity bits for different errors

(7,4) Hamming Code (HC) detects all 2-bit errors and corrects all 1-bit errors. However, there can be 2-, 3- or 4-bit errors that come with the same parity bits as that of 1-bit errors. Eg.: Let ...
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1answer
210 views

use of Hamming Distance in Communication Networks

I am trying to put things in places on the use of Hamming Distance (HD) in error detection and correction in Computer Networks. I'm looking for correction/verification on the following: HD is a ...
1
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1answer
46 views

Why not use the channel capacity as the sliding window size?

In a sliding window protocol, if we use the maximum possible capacity of the channel as the size of the sliding window, efficiency will be theoretically 100%. What is the logic behind not doing this? ...
2
votes
2answers
76 views

What's the real difference between throughput and capacity of a network cable?

I was preparing a presentation in work on GPON & other optical network technologies using documentation provided by a supplier, and the claim it made was "GPON networks have a capacity of up to ...
1
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2answers
99 views

Till which layer does the loopback packet goes?

I want to know exactly till which layer in the OSI model the 127.0.0.1 (loopback) packet goes till it is returned to the upper layer. I read some where it goes till data link layer. but as i was told ...
0
votes
2answers
192 views

scale-free networks and adjacency matrix

Given a distribution over graphs with $n$ nodes having the "scale-free" property, I would like to compute for a pair of vertices $(a,b)$ the probability that they are connected (or more precisely the ...
17
votes
4answers
5k views

If the two generals problem is unsolvable how can we human beings agree on things?

If the two generals problem is unsolvable how can we human beings agree on things? I mean, we communicate everyday and have the same limitations as any communication problem handled by computer ...
3
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2answers
413 views

Algorithm for Dynamic Client Side Throttling

Problem I am trying to come up with an algorithm that will dynamically throttle a client's number of outstanding requests based on the response times of completed requests. Response times are ...
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1answer
53 views

Probabilistic Analysis in real time network : Error in data and feedback channel. Two users communication

I'm studying probabilistic analysis in real time network. We have learned how many attempts in average are required to transmit a packet when there is no error on the feedback channel. With no error ...
0
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1answer
66 views

Hamming Distance, Bit message [closed]

My professor told us to try and remember the equation used for an upcoming exam, however I'm struggling to fit the equation into the question: http://i.stack.imgur.com/RoPYG.png (need a high ...
1
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0answers
24 views

what is correct maximum number of subnetworks? [closed]

ip: 10.5.2.1 subnetmask: 255.255.255.240 {10.5.2.1/28} what is correct maximum subnetworks ???? what is different between classful subnet and CIDR subnet ???
0
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1answer
47 views

How can there be stop and wait protocol for a simplex channel?

Doesn't the receiver have to send back an acknowledgement frame? So how can it send back a frame, since a simplex channel only allows transmission in one direction?
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0answers
63 views

How does 4G LTE work faster than any ordinary Internet connection [closed]

How is 4G LTE faster than any ordinary internet connection? What is the mechanism behind it?
0
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1answer
93 views

How to compress a bit string? [closed]

I'm aware of some techniques to compress a string of characters such as Huffman coding. I need to know whether there is any technique to compress a long string of arbitrary bits? (ideally with high ...
1
vote
1answer
66 views

Sliding window protocol when number of packets is equivalent to the window size

I am currently taking a course in computer networking and I am curious about the following situation: Given $n$ packets and a window size of $n$ (i.e., the number of packets is equivalent to the ...
0
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2answers
2k views

How to calculate probability of packet loss and drop rate?

In a queuing system (M/M/1) with a finite packet capacity $z$, how do you determine the probability of packet loss if we assume that packets are dropped when the system is full? Packets arrive with a ...
0
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0answers
37 views

hybrid or “mixed” networks

I am a mathematician, and I am completely lay in the technical aspects of computer networks and computer architecture. I would like to know if there is any computer network or architecture, protocol, ...