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bromham
Fibre optic
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Failover to mobile broadband if VM goes down

Someone recently posted that they'd switched from VM to a mobile broadband connection with devices tethered to a mobile phone.  Mobile data costs have been reducing, so this prompted me to investigate whether it would be feasible to use mobile broadband for resilience, to use if the VM connection goes down.

TL;DR: It is, cost is low, a real IP address is available but latency is variable.

In case anyone else is interested, I thought I'd summarise.  I use my VM router in modem mode feeding a pfSense firewall and thence to my LAN and WiFi.  pfSense supports USB-connected 3G modems and I had an old Huawei dongle that could be pressed into use.  I discovered that Three offers a free SIM with a free data allowance of 200 MB per month.  No cost and no ongoing charges at all!

Free SIM obtained, Huawei dongle plugged in to the pfSense box, new gateway configured and it works!  One initial concern is that most mobile networks use carrier-grade NAT (CGNAT) with the result that customers don't have a public IP address and it's not possible to do inward connections (aka port forwarding).  I discovered that Three have two APNs: "three.co.uk" (which is CGNAT'd) and "3Internet" (which isn't, allocates a real public IP address, inward connections work).  The only downside is that latency is generally poor with typical RTTs to a DNS server of 100 - 200ms but it's useable nonetheless.

So I now have two Internet connections for resilience, useable by all the devices in the house with the ability to switch from one to the other simply by changing the default gateway in the pfSense box.  And, best of all, it's absolutely free if one happens to have a suitable 3G USB dongle and uses pfSense. The 200 MB free monthly allowance is sufficient for testing and a short outage and one can always buy a PAYG top-up to cover a longer period if necessary.

Further details available if anyone's interested.

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chenks
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Message 2 of 12
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Re: Failover to mobile broadband if VM goes down

indeed, as a failover solution it's ideal, for short periods of time.
as a primary connection source, it's not quite there yet.

i await the usual suspect to pop their head in at some point though Smiley Wink
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bromham
Fibre optic
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Re: Failover to mobile broadband if VM goes down

I agree "it's not quite there yet" but it can only improve.  I predict that mobile broadband will become a serious contender in a couple of years' time for domestic Internet connections, just as mobile phones have largely eclipsed use of domestic landlines.

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chenks
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Re: Failover to mobile broadband if VM goes down

hopefully 5G solves the issue that 4G has (ie poor signals in certain part of a house etc).
if it doesn't then it'll never be a replacement.

however, the solution will never be to use your phone and tether everything to that - that's just insanity.
it'll be proper routers that use the mobile connection to serve the house.
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bromham
Fibre optic
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Re: Failover to mobile broadband if VM goes down

Signal strength isn't too good on my Huawei dongle in the house but an external antenna is the solution to that. I agree that tethering to a phone is a niche solution but, once bandwidth and latency issues have improved, a 4G/5G fixed modem is as convenient as a wired connection (and probably more so).

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Tudor
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Re: Failover to mobile broadband if VM goes down

My Ubiquiti router allows me to have two WAN ports and you can use auto standby switching or load balancing. Plenty of people have done it successfully. 


There are 10 types of people: those who understand binary and those who don't and F people out of 10 who do not understand hexadecimal
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Roger_Gooner
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Re: Failover to mobile broadband if VM goes down

If I were in business and needed an immediate alternative if my broadband went down, I'd have a data only 4G SIM card and a MiFi router with an Ethernet port such as a Huawei B525. All I'd have to do is unplug my switch from my router and plug the switch into the Huawei, which should give both wired and wireless internet.

--
Hub 3.0, TP-Link Archer C8, TP-Link TL-SG1008D 8-port gigabit switch, V6
My Broadband Ping - Roger's VM Broadband Connection
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chenks
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Re: Failover to mobile broadband if VM goes down


@Tudor wrote:

My Ubiquiti router allows me to have two WAN ports and you can use auto standby switching or load balancing. Plenty of people have done it successfully. 


no-one was saying it wasn't possible to do that.

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chenks
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Re: Failover to mobile broadband if VM goes down


@Roger_Gooner wrote:

If I were in business and needed an immediate alternative if my broadband went down, I'd have a data only 4G SIM card and a MiFi router with an Ethernet port such as a Huawei B525. All I'd have to do is unplug my switch from my router and plug the switch into the Huawei, which should give both wired and wireless internet.


of course, that only works if your business is located in area where you get reliable 4G.
most businesses that require internet to function (ie business critical) will have two seperate internet feeds (usually from different suppliers) and coming from different physical routes. almost none of them will be using 4G as one of those routes, as it's simply not stable enough to used for that.

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Roger_Gooner
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Message 10 of 12
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Re: Failover to mobile broadband if VM goes down

I'm lucky enough to get good 4G from all four networks. If I had poor 4G I'd get DSL broadband and pay the insurance for almost guaranteed 100% broadband availability.

--
Hub 3.0, TP-Link Archer C8, TP-Link TL-SG1008D 8-port gigabit switch, V6
My Broadband Ping - Roger's VM Broadband Connection
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