John2vn
Posts: 2
Joined: Mon Jul 10, 2017 5:32 am

Load sharing multiple 3g connections on raspberry pi

Mon Jul 10, 2017 5:48 am

Hi.
My location has no dsl or fibre and has 3g (limited to 4mbps per connection). My cell provider overs a sharedata contract where up to 4 soms can use one data pool.
QUESTION 1
Will bridging 2 3g dongles increase my speed?
Question 2.
Can I install 2 3g dongles on my raspberry pi 3 and bridge,
Link (share the load) watever, and then create a hotspot via the build in wifi to connect to?

Any suggestions as to how to do this? Or any other suggestions. I am fairly inexperienced.

Thanks
John2

drgeoff
Posts: 10765
Joined: Wed Jan 25, 2012 6:39 pm

Re: Load sharing multiple 3g connections on raspberry pi

Mon Jul 10, 2017 1:36 pm

My instinctive reaction is that any speed increase will depend on what you are trying to speed up.

For example, if your goal is to download or stream, at a higher rate, a file from a server over which you have no control, how would that server know to send some packets to one IP address (dongle #1) and other packets to a second IP address (dongle #2)?

On the other hand if you have several applications running (on one or more computers) it would be possible to have outgoing traffic for each application sent to the lightest loaded dongle at that time (and the incoming traffic naturally returned to it). But don't ask me for step by step directions to achieve that. :(

John2vn
Posts: 2
Joined: Mon Jul 10, 2017 5:32 am

Re: Load sharing multiple 3g connections on raspberry pi

Mon Jul 10, 2017 3:43 pm

Your second situation analysis is more in line with what i am trying to do. I have multible devices connected to a single wifi. My laptop, media centre, my wifes tablet and an ip camera system. What i am trying to do is connect to a share the data pool to all the device without having to share the single connection speed. Ie stream from kodi and have the phones on the wifi.

Basically what dispatch/Speedify does but using 3g and a raspberry pi

User avatar
elkberry
Posts: 167
Joined: Wed Dec 28, 2016 9:21 pm

Re: Load sharing multiple 3g connections on raspberry pi

Mon Jul 10, 2017 5:09 pm

What kind of 3G link do you get? I would assume that you get an IP link, but not a data link layer link, unless you booked an data center link, or something similar. So you won't be able to bridge anything here.

Next comes the ugly truth of mobile IPv4: you're behind a carrier grade NAT. While not a show stopper in itself, it may add a lot of problems. Then, IPv4 stacks behave differently when it comes to trying to load balance or bond multiple routes. While you have control over your side, you don't have control over your telco's exit routers, or the ones doing the carrier grade NAT.

Last chance: multiplexing individual TCP and UDP sessions. Again, you may control your outbound traffic, but your inbound traffic is controlled by your telco. So, only NATing possible on your side, but then I haven't seen this to the best of my knowledge.

Android does some multipath bonding via Wifi and data radio, but I don't know how this is done, unfortunately. It probably needs some tricks to work at all...
From ZX81 to Raspberry Pi, but wait ... where's the 7805 gone?

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