In my last year of university (5 years ago) I took a networking seminar. Each student took a look at a different technology to utilize multiple links for internet data transfers.
Initially I was amazed by MPTCP and wondered why it had so little adoption. As I looked into the papers I slowly figured out why. With different links (WLAN, LAN, LTE) their real world characteristics are too different for efficient aggregation. It is the head of line blocking problem times ten.
It might be fine as a back up link, but there are other problems like the limit to TCP and middelboxes dropping unknowns packets.
The challenges outnumber the benefits for consumers and in data centers there are other technologies to aggregate links that operate on a level below TCP.
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ivan4th
I used OpenMPTCPRouter to aggregate 3 LTE connections (via routers connected to directional antenna, with SIM cards from different operators) when I was living in a house in the woods before the war has started I had to leave Russia.
Worked like a charm, giving me up to 180 Mbps or so. May not be that good for aggregating different types of links together, but for using multiple cellular connections it's nearly a perfect solution.
BTW 5G 3GPP specs include MPTCP support, IIRC for aggregating connections going via different gNodeBs (base stations)
fefferkorn
Love it, but aggregating different connections (latency, LTE vs Adsl, fiber) is hard. Tried different algos, but always had network hogs or even higher ping that slowest connection.
What made it work best (and rock stable) was using LTE only, or ADSL only connections having same ping to aggregator (VPS) and have the VPS as near as possible. (latency wise)
I did not had the time to set up multiple redundant aggregators, so my SPOF was the VPS some times. Maybe there is a solution out there.
So far my experience a year ago. Our provider then offered a way cheaper managed solution, thats why we stopped using it.
ajb
Cool, but needs a VPS. A simpler approach is to load balance/ fail over individual TCP/UDP flows, eg using mwan3
I'm hoping that with QUIC, there will be a way to use it's migration feature to load balance more accurately (no need to wait for new flows to start). But, right now there is no way for a middlebox to tell if the server end of an individual flow supports migration, as this is only visible to the client.
steelbrain
I used this when I was in Tallinn. Place I was in didnt have gigabit fiber (probably the only place on the whole street). It worked well for me.
I was using copper internet from local ISP paired with cellular and starlink. Starlink went out for 30 seconds every few minutes but when it worked, it was the fastest of the bunch.
I rented a cheap VPS in the city to use as the other end of this router. The setup worked well overall, I was getting work done along with downloading games with sizes above 100G without worrying too much
In my last year of university (5 years ago) I took a networking seminar. Each student took a look at a different technology to utilize multiple links for internet data transfers.
Initially I was amazed by MPTCP and wondered why it had so little adoption. As I looked into the papers I slowly figured out why. With different links (WLAN, LAN, LTE) their real world characteristics are too different for efficient aggregation. It is the head of line blocking problem times ten.
It might be fine as a back up link, but there are other problems like the limit to TCP and middelboxes dropping unknowns packets. The challenges outnumber the benefits for consumers and in data centers there are other technologies to aggregate links that operate on a level below TCP.
I used OpenMPTCPRouter to aggregate 3 LTE connections (via routers connected to directional antenna, with SIM cards from different operators) when I was living in a house in the woods before the war has started I had to leave Russia. Worked like a charm, giving me up to 180 Mbps or so. May not be that good for aggregating different types of links together, but for using multiple cellular connections it's nearly a perfect solution. BTW 5G 3GPP specs include MPTCP support, IIRC for aggregating connections going via different gNodeBs (base stations)
Love it, but aggregating different connections (latency, LTE vs Adsl, fiber) is hard. Tried different algos, but always had network hogs or even higher ping that slowest connection.
What made it work best (and rock stable) was using LTE only, or ADSL only connections having same ping to aggregator (VPS) and have the VPS as near as possible. (latency wise)
I did not had the time to set up multiple redundant aggregators, so my SPOF was the VPS some times. Maybe there is a solution out there.
So far my experience a year ago. Our provider then offered a way cheaper managed solution, thats why we stopped using it.
Cool, but needs a VPS. A simpler approach is to load balance/ fail over individual TCP/UDP flows, eg using mwan3
I'm hoping that with QUIC, there will be a way to use it's migration feature to load balance more accurately (no need to wait for new flows to start). But, right now there is no way for a middlebox to tell if the server end of an individual flow supports migration, as this is only visible to the client.
I used this when I was in Tallinn. Place I was in didnt have gigabit fiber (probably the only place on the whole street). It worked well for me.
I was using copper internet from local ISP paired with cellular and starlink. Starlink went out for 30 seconds every few minutes but when it worked, it was the fastest of the bunch.
I rented a cheap VPS in the city to use as the other end of this router. The setup worked well overall, I was getting work done along with downloading games with sizes above 100G without worrying too much
TCP Over TCP Is A Bad Idea https://web.archive.org/web/20230228035749/http://sites.inka...
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