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Questions tagged [communication-protocols]

101 questions
57
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6 answers

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 think this one is all text-based?), WHOIS,…
IQAndreas
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29
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7 answers

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 science. Why doesn't it affect us?
user1508072
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1 answer

TCP Connection Termination - FIN, FIN ACK, ACK

I've been reading that to terminate a TCP connection 3 handshakes are required: FIN, FIN ACK, and ACK. However, when closing a connection, Wireshark displays FIN ACK, FIN ACK, ACK; it never displays FIN by itself. However, when establishing a…
Jack
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1 answer

Could a standardized ternary system be more efficient than the binary system?

Could a standardized ternary (base-3) system be more efficient than the binary (base-2) system? Binary is efficient for processing using logic gates, but can be bulky when using for file storage or file transfer. I am interested in the feasibility…
JaceVoracek
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6
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4 answers

Link utilization of sliding window protocol

Before I ask my doubt I would like to state that problem which led me to my doubt. It can also serve as a good example scenario. A $20\ Kbps$ satellite link has a propagation delay of $400\ ms$. The transmitter employs the "Sliding Window protocol"…
Prateek
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6
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3 answers

Difference between CRC and Hamming Code

I am a bit confused on the difference between Cyclic Redundancy Check and Hamming Code. Both add a check value attached based on the some arithmetic operation of the bits in the message being transmitted. For Hamming, it can be either odd or even…
user40759
6
votes
2 answers

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 unpredictable and can be between 7 and 90 seconds. The…
Animal Style
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How to ensure connectedness in a masterless gossip protocol?

This is a theoretical question about how gossip protocols work; I am not asking about any specific implementation or piece of software. I've read the wikipedia page https://en.wikipedia.org/wiki/Gossip_protocol on gossip protocols, and the idea…
Richard Rast
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5
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2 answers

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 arrived at that number. Can someone explain it?
CodyBugstein
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3 answers

Why is it seemingly easier to resume torrent downloads than browser downloads?

I really wonder how torrent downloads can be resumed at later point of time. If such a technology exists, then why is it not possible in browsers? It is often not possible to pause a browser download so that it can be resumed at a later point of…
Sachin Jain
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4
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1 answer

Compute the union of two sets between two endpoints minimizing communication complexity

I have two endpoints, $a$ and $b$, that can communicate through a channel. $a$ is storing a set of fixed-length strings $A = \{a_1, \ldots, a_{N_A}\}$, and $b$ is storing another set of fixed-length strings $B = \{b_1, \ldots, b_{N_B}\}$, with in…
Matteo Monti
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1 answer

What is a "name/variable of base type" in applied $\pi$-calculus?

I'm studying the articleVerifying privacy-type properties of electronic voting protocols which uses Applied $\pi$-calculus to formalize voting protocols and verifies some privacy-related properties. In certain parts of the paper they define some…
Bakuriu
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2 answers

Does a collision occur if two packets are sent at the same time in Slotted AHOLA?

There's something I don't really understand about the Slotted AHOLA protocol, and I hope you can help me: what happens if a station wants to send two packets at the same time? Will it be considered as a collision? If not, when will the first and…
user29882
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2 answers

Byzantine generals problem with signed messages (Lamport)

I have some trouble understanding Lamport's paper about the Byzantine generals problem when it comes to signed messages. He showed that, with signed messages, the number of generals must be at least $m+2$ to tolerate $m$ malicious units\faults (for…
Matthias Preu
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4
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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 application, but "It is sufficient to multicast…
Fabrizio
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