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time sharing network

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I want to create a network hub with the help of raspberry pi for connecting 2 standalone devices with the hub and then provide internet to the hub so that both the devices can access the internet individually.

In any case,I want to use my pi as a network hub. Is it possible? If yes then how?

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  • Ethernet pins don’t belong to the GPIO, they are wired via a network controller chip and magnetics. GPIOs can’t handle hundreds of MHz with differential signalling. – Dmitry Grigoryev 2 hours ago
  • Thanks for the suggestion. Is there any way in which I can use my RPi as a network hub? – abcbc 2 hours ago
  • @abcabc, Well it depends on (1) What you want to access the Internet for, (2) What do you mean by “standalone devices”. Let us begin with the simplest device: A text terminal which consists of (a) black and white, 80 characters x 24 lines, (b) a standard PC keyboard. In other words, no mouse, no graphics. Let me suggest two applications: (A) python learning in text mode only, (2) whether inquiry in text mode only. For (A) The “internet” starts with something like >>> “Hello, What do you want? >>> If you type a python command >>> print(‘abcabc’), The “internet” returns >>> abcabc. – tlfong01 2 hours ago   
  • In other words, you access the Internet to learn text mode python or similar text mode applications. The the Rpi can be the “middle guy”, receiving characters from one text mode terminal A, pass the message to the “internet”, and pass back the text reply to the terminal X. Since text terminals are slow, Rpi can actually entertain perhaps 40 students “at the same time”, like the grand master player playing chess with 40 beginner chess players. What I am telling you is the “Timesharing” operating system in Darmouth College Learning Basic Computer System, in the 1960’s. Fast forward to Rpi. – tlfong01 1 hour ago   
  • Rpi4B has 4 built in UART ports. With USB to UART cables, you have easily set up 20+ UART ports, each receiving and sending text messages, fast enough for python learning students. Just brain storming, not sure if I am dreaming, … 🙂 – tlfong01 1 hour ago   
  • And if your terminal is smart, it can send receive text, can also “translate” from graphics to/from text. In other words, there can be some sort of simple graphics applications, bar charts etc. The bottle neck is the Rpi USB/UART, which is not that “bottle neck” after all, … – tlfong01 1 hour ago   
  • Very old, used Rpi 1, 2, Arduino can easily programmed to be slave text graphics terminals, talking to the master Rpi, “time sharing” the Internet, … – tlfong01 1 hour ago   
  • @tlfong01 thanks for that detailed explanation. – abcbc 48 mins ago
  • @abcbc, You are welcome. Let me continue. What I have suggested is only the very first step. Now let me suppose my neighbour gave me a couple of Rpi1 and Rpi2, and used monitors and keyboards, then I can setup a 24x 7 python learning centre with the master Rpi in my home, and perhaps 4 to 20 RS232 9 pin cables going out of my home window, to other neighbouring flats up to 200 meters away, … – tlfong01 17 mins ago   
  • But of course my neighbour’s kids want to download videos, watch youtube etc. Then it is difficult, because it streaming video needs very high speed, too high for UART to cope. But there is a get around, that is using home Ethernet to shared already downloaded videos (not youtTube though). The trick is to set up a FTP server (not http/web server whcih needs high speed) just for download/upload big files. You might like to google “Pure-FTPd” to get a rough idea of sharing files within a home Ethernet, using CAT5 cables (Not wireless Wifi). – tlfong01 14 mins ago   
  • Now only one master Rpi/WinPC can access Internet via the home wideband router. Otter slave Rpi1, Rpi2 use Ethernet CAT5 cable to form a Ethernet switching network. Now every slave can download/upload to the master ftp server. Ethernet is ver fast, fast enough to upload/download big files. (Actually I am using Pure-FTPd to share/backup files for my Micky Mouse projects). Of course you can also setup a web/http server within your home Ethernet, but performance might not be good. Ah, jogging time for me now. I need to go. End of brainstorming. – tlfong01 7 mins ago   
  • One more thing, in case your are curious why I am talking old things. It is because I am an old timer. Some 20 years ago, when I learned linux 0.9, it took me one hour to download one mega byte of linux distribution (forgot Red Hat or something) into 3.5″ floppy disks (forgot if 1.4M capacity), and I needed many floppies to build the linux os, … So you see, I am patient enough to wait for one hour to download 1 mega byte! 🙂 – tlfong01 9 secs ago   Edit   
  • Of course now I have 1Gb/s wide band optical firbe comeing to my home, 2.4G/5G Wifi router, and my smart phone is 4.5G, too fast for me to be comfortable, … I still prefer those were the days, … – tlfong01 just now   Edit   

3 Answers

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No. There is no way software would be fast enough to handle the Ethernet protocol. You need dedicated hardware to handle the bus.

https://simple.wikipedia.org/wiki/Ethernet

0

If you need more LAN interfaces, the best solution in terms of performance per dollar is to get several USB to LAN adapters.

For low speeds (below 10Mbps), an SPI to LAN module can be used. Such a module can indeed be wired to GPIO SPI pins. You will want to check if a Linux driver is available before buying a module, since many of those are made for Arduino and may lack Linux support.

Also, you may want to take a look at Banana Pi R1. It’s quite old by now, and you’ll have to install a Banana Pi specific distro (Bananian or Armbian), but it’s a good option for a hub/NAS project.

0

Definitely NOT – for a start Ethernet uses galvanically isolated differential signalling.

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