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

learn more… | top users | synonyms

-1
votes
0answers
8 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 learn how many attempts in average are required to transmit a packet when there is no error on the feedback channel. With no error ...
0
votes
1answer
20 views

Hamming Distance, Bit message [on hold]

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
vote
0answers
15 views

what is correct maximum number of subnetworks? [on hold]

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 ???
2
votes
0answers
18 views

How did NASA remotely fix the code on the Mars Pathfinder? [migrated]

In 1997, NASA remotely fixed a bug that caused priority inversion on their Mars Pathfinder. How did they go about doing this? What kind of communication protocols are used? How do they update the ...
0
votes
0answers
13 views

TCP priority assigments [on hold]

I have a question. Three senders are attached with one receiver. The sender A has high priority with 1 value The sender B has Medium priority with 0.6 value The sender c has low priority with 0.2 ...
0
votes
1answer
5 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?
1
vote
0answers
14 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
votes
1answer
40 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 ...
0
votes
1answer
18 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
votes
0answers
9 views

What is a Buffer Insertion Ring network?

In some scientific papers I've been reading, Buffer Insertion Rings have been mentioned. Yet a Google Search on the topic turns up nothing useful that can help me quickly understand what it is. Can ...
0
votes
0answers
24 views

What is the difference between disaster recovery at the data link layer and the transport layer?

What is the difference between disaster recovery in the network data transmission, when this process is performed by the link layer and the transport layer? The two approaches can be used together, or ...
0
votes
2answers
170 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
votes
0answers
27 views

Understanding Networking RTT over parallel connections

I have answers to questions but it doesn't explain how they got the answer. I already have the answers, I'm trying to understand them. Question 1: A DNS lookup is necessary to view a web page. ...
0
votes
0answers
21 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, ...
1
vote
2answers
117 views

Why is CAN protocol preferred to be used in automotive application?

Is it only because of the fact that it is asynchronous and can be used for long distance message transfer. An example of where other protocols will fail would help. Thanks.
0
votes
0answers
22 views

The maximum & minimum number of sources that can be multiplexed so that no data loss occurs on TOKEN BUCKET?

A link of capacity 100 Mbps is carrying traffic from a number of sources. Each source generates an on-off traffic stream; when the source is on, the rate of traffic is 10 Mbps, and when the source is ...
3
votes
1answer
60 views

Unsplittable flow in capacitated networks

I have an undirected network with capacitated links/edges. Between some nodes unsplittable traffic has to be routed. All demands and capacities are known, but it is uncertain if all flows can be ...
1
vote
1answer
73 views

Why the analysis of Aloha protocol uses Poisson distribution?

Pretty much in all of the analysis of the Aloha protocol that I read, it is assumed that the distribution of packet arrivals is Poisson. What is the rationale behind it? Isn't it actually binomial ...
0
votes
1answer
58 views

Why escape and escape in byte stuffing?

Denoting the two special bytes as FLAG and ESC, and any other as X, where FLAG denotes the start and end of the message and ESC is used to escape any flags within the original message, if the original ...
1
vote
0answers
25 views

Why are there so many available loopback addresses? [closed]

I don't really know whether this is the correct site where to post this question, I'm sorry if I'm mistaken. I am studying computer networks and during the explanation of the ip protocol the ...
0
votes
0answers
17 views

Reference for Motivation of WSN Localization in 3D

I need references to motivate the reader about 3D Wireless Sensor Network Localization problem. I have found many references about 2D WSN localization, however, there is a lack of 3D WSN Localization ...
0
votes
1answer
35 views

What is the correct term for “time to establish a connection” [on hold]

I don't remember what is the term for "time to establish a connection". For example in a smartphone, when I lost the wifi signal and the phone try to get mobile data connection it spends a bit of ...
1
vote
1answer
45 views

Applying Brewer's theorem (CAP) to a single node

I'm going through Brewer's theorem and its proof by Nancy Lynch and Seth Gilbert. But the paper left me with one question. What prevents the theorem from being applicable to a single node? I haven’t ...
0
votes
2answers
65 views

Probability of Success in Slotted Medium Access

Suppose you have a network which uses time division multiplexing (i.e. Slotted Aloha). There are $N$ nodes each transmitting in a given slot with probability $p$. I understand that the probability a ...
1
vote
1answer
30 views

Aggregate Rate and Poisson Process in Aloha

I'm having a hard time understanding what is mean't by the aggregrate rate $\lambda$ and what it means for throughput in unslotted and slotted Aloha protocols. The more I seem to read about poission ...
0
votes
0answers
44 views

Question from GRE subject on finding the size of transport layer

I am here to ask for guidance to a question as to how approach to such questions not seeking answer to homework ,as this question i came across in an MCQ's book.so please realize before downvoting ...
-1
votes
1answer
95 views

Which addresses belong to which network, given a fixed subnet mask?

The subnet mask for a particular network is 255.255.31.0. Which of the following IP address belongs to this network? 172.57.88,62 & 172.56.87.233 10.35.28.2 & 10.35.29.4 ...
-2
votes
1answer
44 views

Find the approximate number of messages (n) that need to be tried

Find the approximate number of messages (n) that need to be tried before finding two that had the same message digest (size k) with probability 0.8. You need to find n as a function of k . What is n ...
2
votes
1answer
56 views

Choice of algorithm for hierarchical clustering for minimizing network communication costs

Suppose I have a large distributed task running on a cluster system where part of the workload is compute bound and part depends on network performance. Data transfer is not completely homogeneous ...
0
votes
1answer
43 views

How can one come up with reasonable IP subnet allocations?

An ISP has following chunk of CIDR-based IP addresses available with it: 245.248.128.0/20 The ISP wants to give half of this chunk addresses to Organization A, and ...
0
votes
1answer
74 views

Layered Structures

I'm trying to check how general and valid protocol suite system ( layered structure ) are. Does anyone know if radio communication ( broadcast ) via AM or FM , for instance can be viewed in the light ...
-1
votes
1answer
49 views

Selecting a M.S. in CS focus [closed]

I need to pick a focus in my Masters program. The running candidates are Networking Bioinformatics Data mining Computer Image Recognition In order to avoid this becoming a discussion, I'd be ...
1
vote
1answer
53 views

What's the point of Subnet Masks?

I'm having trouble understanding the point of Subnet Masks. I was reading a nice article on Tech-FAQ on the topic, but it has left me a bit confused. When I first heard about Subnets, it was ...
3
votes
2answers
817 views

Why is the throughput (performance) of the Slotted Aloha protocol ≈ 0.36

I've read that the throughput - that is, the amount of good useful messages relative to capacity - of the Slotted ALOHA protocol for communication networks is roughly 0.36%. But its not clear how we ...
2
votes
1answer
138 views

Why is the throughput (performance) of the Aloha protocol ≈ 0.18?

I've read in a few places (like here that the throughput - that is, the amount of good useful messages relative to capacity - of the ALOHA protocol for networks is roughly 0.18%. But its not clear ...
9
votes
1answer
128 views

Can the end-to-end principle be formalized?

In the late 1990s, when I was in graduate school, the paper JH Saltzer; DP Reed; DD Clark: End-to-end arguments in system design. ACM Trans. Comput. Syst. 2(4):277-288, 1984. ...
-1
votes
1answer
35 views

TCP repeated acknowledgement

My professor has asked this (exam) question and it actually makes no sense to me: TCP offers a reliable, bidirectional byte stream over the best effort packet delivery in IP. For reliability, a ...
-2
votes
1answer
218 views

What is the maximum achievable throughput in this communication using sliding window protocol?

Station A is sending data to station B over a full duplex error free channel. A sliding window protocol is being used for flow control. The send and receive window sizes are 6 frames each. Each frame ...
1
vote
2answers
101 views

Why does packet data don't need trailer/footer while frame needs it?

Why does packet don't need trailer/footer while frame needs it? I am trying to understand networking concept regarding OSI & TCP/IP layering. I have googled a bit and it says that the footer in ...
3
votes
0answers
1k views

totally ordered multicast with Lamport timestamp

I'm studying Distributed Systems and synchronization and I didn't catch this solution of totally ordered multicast with Lamport timestamps. I read that it doesn't need ack to deliver a message to the ...
0
votes
1answer
209 views

Can we break the Shannon capacity? [closed]

I have a friend working in wireless communications research. He told me that we can transmit more than one symbol in a given slot using one frequency (of course we can decode them at the receiver). ...
0
votes
0answers
47 views

Picking an optimal initial congestion window size (high bw, high latency and short bursts)?

What is a known strategy to approach a situation where short bursts of data are being sent very often over a high bandwidth, high latency cable? I am aware of cubic but even that does not utilize a ...
-1
votes
1answer
70 views

ARQ Protocols and sequence numbers [closed]

What will happen if sequence number is not used in an ARQ protocol (e.g, Go-back-N, selective repeat)?
1
vote
0answers
39 views

Buffering packets vs. low latency routing [closed]

I am considering strategies to compare the performance of routers with buffers vs. their lower latency counterparts in a simple network setting (N clients communicating with each other randomly ...
1
vote
1answer
681 views

Sliding window protocol, calculation of sequence number bits

I am preparing for my exams and was solving problems regarding Sliding Window Protocol and I came across these questions.. A 1000km long cable operates a 1MBPS. ...
0
votes
0answers
99 views

Closed network system that use OSI model to connect to another network?

The OSI model can be used for LAN and WAN networks, allowing the interconnection of [vendor] closed systems and it only informs what each layer have to do. Someone said that this phrase is false, ...
0
votes
1answer
328 views

Physical layer services & hardware protocols [closed]

I am searching the content of this topic but I am not sure what should be the content for this topic. This is relate to Computer Network. My topic is ...
-1
votes
2answers
331 views

TCP congestion problem

Consider an instance of TCP’s Additive Increase Multiplicative Decrease(AIMD) algorithm where the window size at the start of the slow start phase is 2 MSS and the threshold at the start of the first ...
1
vote
1answer
99 views

How to present ping data from ICMP timestamp

The ICMP timestamp protocol is useful for determining which path — forward or reverse — is contributing to the jitter on the line. In an ideal world, all computers would have an excellent ntpd, and ...
1
vote
0answers
78 views

NTP: synchronisation of time between two machines for ICMP timestamping

Some guy on the internet recommends using the same ntp server when it is required to troubleshoot asymmetric routes through ICMP, and it's somewhat important to have synchronised time between the two ...