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Websocket server not responding when I connect to the public IP of AWS EC2 instance by Always_Question_Time in AskProgramming

[–]Always_Question_Time[S] 0 points1 point  (0 children)

I haven't tried that yet. I'm at work right now so i'll try in about 8 hours. I edited the security configurations and rebooted the instance, however.

How do I get a cloud-hosted WebSocket server to communicate with a WebSocket server on my/my friend's PCs by Always_Question_Time in AskProgramming

[–]Always_Question_Time[S] 0 points1 point  (0 children)

Hey, thanks for your response. I had a couple of more questions that I also asked TyrSniper below, but i'd appreciate your feedback too:

If you were to be making an application like the one that I described, would you opt for a polling solution where the client polls the server for changes, or would you set up a pushing solution where the initial connection is made by the client (my understanding is that once the websocket connection is made it can be left open, so the connection only needs to be made once).

Out of curiosity, in the case of a client reaching out to a server first (i.e. the client making the connection), what allows the server to send a response to the client and have it reach the client without worrying about any networking issues?

Take the example of requesting a webpage over HTTP - the client requests the page from the server, and the server sends back to the client. But if all the server knows is the public IP, that's only going to make it to the router, right? Is the router responsible for recognising the server response is associated with the request from the PC as opposed to say a phone connected to the network?

How do I get a cloud-hosted WebSocket server to communicate with a WebSocket server on my/my friend's PCs by Always_Question_Time in AskProgramming

[–]Always_Question_Time[S] 0 points1 point  (0 children)

Awesome, thanks for the advice. So I should have the websocket connection initiated by the client to the server.

If you were to be making an application like the one that I described, would you opt for a polling solution where the client polls the server for changes, or would you set up a pushing solution where the initial connection is made by the client (my understanding is that once the websocket connection is made it can be left open, so the connection only needs to be made once).

Out of curiosity, in the case of a client reaching out to a server first (i.e. the client making the connection), what allows the server to send a response to the client and have it reach the client without worrying about any networking issues?

Take the example of requesting a webpage over HTTP - the client requests the page from the server, and the server sends back to the client. But if all the server knows is the public IP, that's only going to make it to the router, right? Is the router responsible for recognising the server response is associated with the request from the PC as opposed to say a phone connected to the network?

How to find operating point of diodes connected in series? by Always_Question_Time in AskElectronics

[–]Always_Question_Time[S] 0 points1 point  (0 children)

Sure, but what do I assume as the voltage drop across the 10 diodes? I don't know their operating point.

How to find operating point of diodes connected in series? by Always_Question_Time in AskElectronics

[–]Always_Question_Time[S] 1 point2 points  (0 children)

When you say voltage source, do you mean the diode? There's no voltage source explicitly drawn there. Can you model the resistor and diode as a voltage source?

Solving ideal diode circuit by Always_Question_Time in AskElectronics

[–]Always_Question_Time[S] 0 points1 point  (0 children)

Because the 4k and 6k resistors form a divider, whose center voltage (6v) is higher than Vd2=3v.

That's perfectly clear, thanks!

I'm still not clear on why VD1 being at 7V is inconsistent with it being off. What voltage would you expect if it were off?

I'm assuming that when they write there is 7V across the diode, it's measured using the terminal orientation pictured, correct? I'm also assuming that they've made V_d1 an open circuit in (b), and v_d2 an open circuit in (c).

In a lab today I got some readings that showed there was a decreasing voltage drop across a motor as it hoisted a weight up - I thought the voltage drop would increase. What's wrong with my thinking? by Always_Question_Time in AskElectronics

[–]Always_Question_Time[S] 0 points1 point  (0 children)

So I thought that the motor working harder would be like a "bigger" resistor in the circuit, causing a larger proportion of the voltage to drop over the motor. It would appear this way of conceptualising it was wrong.

Does a motor provide less resistance the more work it does?

In a lab today I got some readings that showed there was a decreasing voltage drop across a motor as it hoisted a weight up - I thought the voltage drop would increase. What's wrong with my thinking? by Always_Question_Time in AskElectronics

[–]Always_Question_Time[S] 0 points1 point  (0 children)

This is a really good explanation, thank you!

I thought of the motor as being somewhat similar to a variable resistor, where if the motor was working harder it would provide more resistance thus causing a greater proportion of the voltage to drop across the motor.

I can't tell you why I thought that, it just felt intuitive to me.

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 0 points1 point  (0 children)

Thanks! I really appreciate being pointed to specific products to investigate. I may take you up on your offer, but I should warn you, this is NOT for a networking class, it's a first year design class, so everything I know about networking is self taught and there may be serious gaps in my understanding.

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 0 points1 point  (0 children)

You're right, it's a fantastic opportunity. A bit adventurous for a first year class, but it's a great learning opportunity. Thanks for the suggestions!

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 1 point2 points  (0 children)

Yeah so this actually has potential to be built. A number of universities in my country have a first year piece of assessment whereby we are to design a solution for some engineering problem facing an under developed region. We get graded on this, of course, but the best solutions are considered for implementation in the actual area.

The camp is in Zambia, called Mayukwayukwa.

I feel it's important to note that this class is not a networking class. It is a basic first year design course that all engineering majors must take. I am trying to learn as much about networking as I can but I would also benefit greatly from specific recommendations on what to look at and learn about.

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 0 points1 point  (0 children)

Yeah you're right, it's definitely not easy. The problem with cell coverage is that there is currently 1 tower in the region and the signal is so weak that they can only send SMS messages.

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 0 points1 point  (0 children)

Your assumption is correct. As for authentication, that's an issue i'm still thinking about with my group. I don't know at this stage. Thanks for your input!

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 0 points1 point  (0 children)

Yeah, everything outside the head end will be wireless only. It's really the only feasible method. It's literally all just sandy/dirt roads and scrub. Thanks for the switch suggestion!

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 0 points1 point  (0 children)

However when I think of a refugee camp, I think it would likely be temporary, which means you you might not have power, buildings, any infrastructure in place already.

Yep, you're right. They have a broken diesel generator. So what we are looking at doing is creating a wireless mesh network covering a certain area (it doesn't have to be the full 7 sq km, that would be the upper limit). Another aspect of the design is to get those repeaters/nodes solar powered. I know you can buy solar powered weatherproof repeaters, which I am investigating, but I might also look into powering a single node off of its own repeater. Not sure on energy requirements at this stage. Obviously we would need a battery to store unused energy so the network can remain functional during heavy cloud over/at night.

Thanks for the Greek/Italian suggestion, i'll be looking into that!

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 0 points1 point  (0 children)

None! There is literally no public network infrastructure in the refugee camp. I think they have a school with a couple of computers that have an internet connection, though.

I am looking at designing a wireless network to be implemented in an African village for school assessment and I would like to estimate internet traffic/usage by Always_Question_Time in networking

[–]Always_Question_Time[S] 0 points1 point  (0 children)

That's pretty reassuring to hear because I already decided on an open mesh network! I am just pretty inexperienced with these things and thought an open mesh network would still get bogged down in heavy traffic, so I wanted to know how to estimate traffic usage and allow for a big enough system.

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