Possible to combine 2 different ISP FTTP lines?

Hello all! I apologise in advance for the long post, but I was wondering if anyone could perhaps help or provide any advice?

Background:

I work as a software tester for a well known video games company who is currently working at home. Therefore, for me having the fastest, most reliable broadband possible is essential due to downloading the game/app as quickly as possible, get the game tested including network, upload the reports with media and then move onto the next game. The size of some of these games now are easily into 50GB+ capacity.Sometimes I have to download multiple applications due to being released in different regions, which require their own checks to perform.

I currently have BRSK BetterNet 1000 as this gives me up to 900mbps down/900mbps up in order to do my work more proficiently. However, this service is supplied overhead to my house (bungalow), so the cable is a little low..I live in an area that now tends have some anti-social behaviour, therefore I was a little worried incase the cables were vandelised. So I've ordered a different 1gbps line with PlusNet as a backup via underground just incase BRSK has any issues.

Question:

Just out of curiosity, After getting the second FTTP line installed (I'll have one over head and one via the underground ducts). Is it possible to combine both of these 1Gbps FTTP lines into one 2Gbps line, or is this not possible?

If it is possible, how would one go about doing it? What equipment would I need etc?

Apologies for the long post! The 1Gbps would be more than enough for me personally, however for my work, I needed to get the second line for reliability as I need to be online all the time working from home!!

Many thanks!

Kind regards,
Keith

Edited by Keith016377 (Mon 05-Aug-24 21:33:45)

Yes it's possible but you'll need a dual WAN capable Router with Load Balancer, Failover or Link aggregation capabilities. Personally, I use a Draytek 2927 which will do what you want. Each ISP will need to present their connection via an ONT or a similar.

https://www.draytek.co.uk/products/business/vigor-2927

I note that router only has gigabit LAN ports so you wouldn't be able to use the whole connection on a single device.

In reply to a post by Keith016377:

Question:
Just out of curiosity, After getting the second FTTP line installed (I'll have one over head and one via the underground ducts). Is it possible to combine both of these 1Gbps FTTP lines into one 2Gbps line, or is this not possible?

It's sort of possible; you won't get a full 2Gbps per individual transfer/connection, irrespective of single or multi-streams. There used to be some xDSL providing ISPs who offered bonded connections over 2 phonelines, this effectively doubled your speed. But required using a single ISP and specialist hardware

The best you can expect is to be able to use the full bandwidth if you're initiating multiple distinct transfers. I.E. With 2 FTTP connections a single 50GB transfer will take about 7.5 minutes, essentially maxing out 1 line. Or running 2 distinct 50GB downloads will take ~7.5 minutes, but should instead be using the full capacity of both lines.

Therefore, for the fastest connection you need the highest speed you can get on a single line. For reliability, a wireless ISP or mobile data may offer more security. As even with diverse connections into your house, they're still likely to hit the same cabinet not too far down the road.

When I needed the redundancy, I also used the Draytek 2927 with VM, BT and a Smarty SIM. The VM and BT where always on concurrent load balanced, with the SIM only used as a last ditch emergency fail over. I found this solution to be excellent, to the point when I did have VM "glitches", I never really noticed.
If the 1Gb ports are an issue, and you have deep pockets, the Draytek 3912 has 10Gb ports ....

Edited by Adduxi (Tue 06-Aug-24 09:55:03)

How technical are you with networking and servers?

The N305 version of this would easily handle a couple of 1G links, using OPNSense and it would be relatively straightforward to configure a dual-WAN configuration. It's got 2.5G ports out the box, and 10G SFPs so plenty of expansion too.

The biggest downside is that you'd have to build and configure it yourself, hence the question at the top! Personally speaking, I run a variation of this with Proxmox / OPNSense and can easily saturate 2.5G interfaces even with the much lower spec N5105 CPU. The N305 will be way more capable.

Edited by daern (Tue 06-Aug-24 11:18:38)

As others have said, it's generally not possible to get 2Gbit from this solution. I say generally because it is technically possible. But you'd need a setup that likely makes it just not worth it. But, I'll detail that at the end of the comment.

What I did for a while, when ADSL was all that was available. I had two connections with two ISPs with around 7Mbit sync on each. I was already working from home and so what I'd do is route things like like VPN and other things by either host or port using source routing and iptables over one connection and the bulk of stuff for others users in the house over the other. In that way, they couldn't interfere with my work on such a limited speed connection.

I also had a script that would ping from both every minute and if one went down everything would be routed over the other until it returned.

You can also have NAT configured to use a pool of NAT outputs for both connections. That would spread the load over the connections but you still wouldn't get 2Gbit from a single connection.

Now, how you COULD get 2Gbit on a single connection but only to individual endpoints you control. Well you would frist need to upgrade your network to at least 2.5gbe. Then you could use something like openvpn to create L2 tunnels to the same locations. Then on each side you could use link aggregation to join those two L2 tunnels into a single one, and then run IP over that tunnel. You could repeat this to any number of locations you control.

But to me, that's a lot of work for a very limited return and with a lot of caveats and limitations.

Brilliant guys!

Thank you so much for your responses. Unfortunately I am not technically minded when it comes to networking and servers, so I wouldn't be able to go that route.

It does seem that I would need quite a bit to do, but as mentioned there would be very little gain if any!

Many thanks again for your help/advice!

In reply to a post by agent_r00t:

Now, how you COULD get 2Gbit on a single connection but only to individual endpoints you control. Well you would frist need to upgrade your network to at least 2.5gbe. Then you could use something like openvpn to create L2 tunnels to the same locations. Then on each side you could use link aggregation to join those two L2 tunnels into a single one, and then run IP over that tunnel. You could repeat this to any number of locations you control.

That's still only going to provide 1Gb bandwidth for single stream applications. It's no different to using a static LAG or LACP on switches. So you're back to the same thing of being able to do 2 things in the same time as 1, but not getting the 1 thing done in half the time.

The analogy that tends to be used is cars on a road. The cars don't get split up. So with 2 lanes your single car is limited by the speed, not the number of lanes. Add another car and they've each got their own lane. Effectively doubling the bandwidth.

About the only thing that'll make use of it is SMB multichannel. But that requires multiple NICs and is just a pain, at least with Linux as the server. Better off upgrading the link speed.

In reply to a post by Noolah:

That's still only going to provide 1Gb bandwidth for single stream applications. It's no different to using a static LAG or LACP on switches. So you're back to the same thing of being able to do 2 things in the same time as 1, but not getting the 1 thing done in half the time.

Flat LACP, yes. But using balance-rr (if supported by the switch) or balance-alb under linux, for example, it will shift the frames between the channels not using the hashing method standard LACP 802.3ad. uses.

That's not to say it doesn't pose real world problems. Packet order being one of them (unlikely two ISPs will have the same time to destination as eachother). But for upload/downloads it would likely be fine to give increased throughput. But low latency streaming, voip etc might well take a hit when UDP packets arrive out of order. Gaming too would get latency problems. But, it would achieve the speed of both connections.