[txutxu]

At home/lan we use LACP, VRRP... I mean link aggregation and HA needs are solved time ago.

With multiple ISPs, or on a complex enough LAN, we can use multiple routing tables + weights too.

Also, if the ISP at home can do 10Gbps, 1Gbps, 300 Mbps whatever... I want to be able to use them with a single path, so there is no gain using multiple paths. Eventually, when I have cable+wifi connected at the same time, I use to force one of both, cannot see a reason to prefer using both at the same time.

Maybe the latency thing? Never had that issue at home, but could understand that usage case "just use the network segment with less latency to reach $thing".

[semi]

> Also, if the ISP at home can do 10Gbps, 1Gbps, 300 Mbps whatever... I want to be able to use them with a single path, so there is no gain using multiple paths. Eventually, when I have cable+wifi connected at the same time, I use to force one of both, cannot see a reason to prefer using both at the same time. >

I don't understand why you would want to be able to use them with a single path. the gain would be being able to aggregate them and have individual tcp streams faster than any one IP connection could handle.

Though personally I think the resilience is more appealing. Not having to have a hard cutover when wifi degrades as I walk away would be nice

[txutxu]

If my ISP gives me 10 Gbps, I want my PC to have (at least) a 10Gbps single path to the router.

So, If I already have a 10 Gbps path to the router, I don't want to add a 300 Mbps failing air path added to my way to the router.

In the context of the parent (at home networks), I think most people has two paths... WiFi or RJ45-UTP. And with that multipath setup (WiFi + RJ45, I don't get why other comments are talking about cellular networks "at home") is not usual to walk away; right, you could walk, as far as long is the rj45 cable, but...

To keep HA on WiFi when walking around, there are other technologies more battle tested than MPTCP.

[lo0dot0]

For a long time enterprise firewalls (and more recently SD-WAN) allowed load balancing between different links, but unlike MPTCP the traffic of a single TCP connection is not split up. This is in line with the established network admin wisdom saying that reordering packets of a TCP connection hurts performance.

https://community.fortinet.com/t5/FortiGate/Technical-Tip-Ho...

[matttbe]

Some ISPs in Europe are using MPTCP for people being too far from the street cabinets. Typically, for people in the countryside, with < 50 Mbps. Thanks to a transparent proxy installed in the home gateway, and servers in the ISP's network, they can combine both the fixed and cellular networks, and use the fixed one in priority.

MPTCP can also be very interesting for mobility use-cases, even when one network is used at a time, e.g. switching from WiFi to cellular, or different cellular networks in the train, etc.