PoE VDSL2 Modem, Do they exist?

I'm currently working through a bit of a network upgrade and would like to swap my ECI BTOR modem for something that can be powered via PoE (24v, preferably)

My setup will be as follows:

VDSL Modem (Bridged) -> Ubiquiti EdgeRouter X -> Ubiquiti ToughSwitch 8 port -> Ubiquiti UniFi AC Pro access point(s)

As the switch supplies PoE on any ports, this will be used to power both the WiFi AP's and the router.

The router will pass through PoE at whatever voltage it is given (48/24v) so would be nice to have PoE powered modem also, as it would save running AC up to the window sill where the NTE is

I'd love it if Ubiquiti would make a VDSL modem as it would integrate nicely with my setup, but not holding my breath!

as a bit of a background, I am a technician for Caleycom.net , a WISP operating in Aberdeenshire and have a lot of experience and knowledge on the Ubiquiti platform, hence why as much of the kit is possible is from them

My other option was to get something like this: https://linitx.com/product/13305

To split the PoE+Data from the router into two cables and power something like a B-Focus or HG612. Has anyone got any experience running them on 24V. Cant imagine it working too well?

You either don't know or forgot that the OR modems aren't! They are modem/routers in bridged mode.

All you need is a true modem, if there is a VDSL2 one with PoE. Note VDSL is not what you want, whether a modem or a bridged modem/router.

In reply to a post by RobertoS:

You either don't know or forgot that the OR modems aren't! They are modem/routers in bridged mode.

All you need is a true modem, if there is a VDSL2 one with PoE. Note VDSL is not what you want, whether a modem or a bridged modem/router.

I know that the OR modems aren't PoE comparable, I never claimed they were, I also never claimed they were anything more than a bridged modem

VDSL is not what I want? Fairly sure it is

I want a bridged VDSL modem, to connect to my ubiquiti router. But a modem that can be powered by 24v Passive PoE instead of a 12v wall jack

That should work with a HG612 - just make sure you use the modem PSU as the source. You will, however, need to ensure the power plug and socket are correct size.


Why should you need to run te modem on 24v anyway?

In reply to a post by MHC:

That should work with a HG612 - just make sure you use the modem PSU as the source. You will, however, need to ensure the power plug and socket are correct size.


Why should you need to run te modem on 24v anyway?

Because the router is powered remotely from a switch, which outputs 24v or 48v Passive PoE.

Whichever voltage I choose to power the router at, is also the voltage it will spit out.

The PoE coming from the router will be 24v

There is no mains supply near the master socket

Power will be delivered as follows:

Mains into switch
24v from switch to router over Ethernet
24v from router to modem over Ethernet

I thought I had explained clearly and politely. I know I did the second of those.

I also know I didn't suggest that the OR "modems" are PoE capable. By "aren't" I meant they are not modems.

What I also know is that a modem is a modem, and there is no such thing as a bridged modem. Bridging is when the router part of a modem-router is bypassed. The router is bridged over with the modem output going direct to an Ethernet socket instead of to the router component and from there to the built-in switch if present.

A plain modem if there is a suitable one is your ideal buy, as it will be cheaper and need less power than a modem-router that you put into bridged mode.

A VDSL modem or modem-router will not work on Openreach FTTC. It would be useless. Just like an ADSL modem or modem-router doesn't work on ADSL2+.

The FTTC service is VDSL2 between the cabinet and the premises.

Edited by RobertoS (Tue 26-Jan-16 00:44:08)

Perhaps you'd better also check whatever you get complies with the Section 3 requirements of the Jan 16 SIN 498v7.

So, don't use the PoE option from the switch. Take a standard Ethernet output and use on of the device pairs you have linked to, install te HG612 PSU close to the switch and feed the power from that into the combiner.

The earlier generation Openreach modems can overheat with their standard 12v supplies, and I doubt the internal PSU would cope as it far exceeds its design specification.

If you can find a UK supplier the wifiqos / wifi-texas WS-POE-12v should do the job - it takes Ubiquiti/Mikrotik passive 24v PoE and provides 12v at upto 1A

In reply to a post by RobertoS:

I thought I had explained clearly and politely. I know I did the second of those.

I also know I didn't suggest that the OR "modems" are PoE capable. By "aren't" I meant they are not modems.

What I also know is that a modem is a modem, and there is no such thing as a bridged modem. Bridging is when the router part of a modem-router is bypassed. The router is bridged over with the modem output going direct to an Ethernet socket instead of to the router component and from there to the built-in switch if present.

A plain modem if there is a suitable one is your ideal buy, as it will be cheaper and need less power than a modem-router that you put into bridged mode.

A VDSL modem or modem-router will not work on Openreach FTTC. It would be useless. Just like an ADSL modem or modem-router doesn't work on ADSL2+.

The FTTC service is VDSL2 between the cabinet and the premises.

Fine, either a bridged router (Like a HG612 / B-Focus) or a plain modem. Either will deliver essentially the same result. That better?

I assume you are now going to go round the rest of the forum moaning at people who say ADSL when they actually mean ADSL2+.

It is clear from the title and context of the forum that a VDSL2 device is what is required, but if it makes you happy, I'll remove all references to VDSL and replace with VDSL2

In reply to a post by tdw42:

The earlier generation Openreach modems can overheat with their standard 12v supplies, and I doubt the internal PSU would cope as it far exceeds its design specification.

If you can find a UK supplier the wifiqos / wifi-texas WS-POE-12v should do the job - it takes Ubiquiti/Mikrotik passive 24v PoE and provides 12v at upto 1A

The WS-POE-12v does look like a suitable device for my requirements, thank you!

I'd prefer something that is PoE native, but this is a close second as it'll take a 24v PoE input and output a 12v DC jack compatible with my existing ECI B-Focus

If I had recalled the VDSL2 in the Subject when reading your posts, I would simply have pointed out it would have been better to continue including the 2.

However, your brusque "VDSL is not what I want? Fairly sure it is" definitely needed contradiction.

You may not think it, but when talking about signal protocols or distance units or transmission speeds, it does very often matter. If you don't want people genuinely trying to ensure you don't buy an inappropriate piece of kit that would seem rather foolhardy.

Your continual reference to obtaining a bridged (PoE) modem also contributed hugely to making me think you didn't fully understand what you wanted.

Most people say "Oops, yes" when their error is pointed out. They don't get snooty.

Edited by RobertoS (Tue 26-Jan-16 10:41:44)

Hi - as someone with much less knowledge, but who is doing research to replace basically all his existing networking gear with similar Ubiquiti gear, I'm very interested if you managed to find a PoE powered VDSL2 modem?

A bit of googling found this: http://www.yoda.com.tw/model_Tabs.php?type=VDSL2&pna...

It would "seem" this is a PoE (802.3af compliant) VDSL2 modem - that said whether it is purchasable anywhere is another question...! Also as no expert, I have no idea if this would be powerable using the 24v passthrough PoE that the EdgeRouter-X would provide - rather than the 802.3af which the Ubiquiti Switches can provide.

Interested in your thoughts. I was planning to replace my existing Router/Wifi free-thing-from-plus.net with a Ubiquiti EdgeRouter X, Ubiquiti 8-port PoE Switch (US-8-150W) and a few UniFi PRO AC UAPs. The idea that I could expand that to replace the VDSL2 modem is pretty appealing.

amazon have this power spliter from tplink about £10
https://www.amazon.co.uk/TP-LINK-TL-PoE10R-TL-POE10R...

The 'Yoda' device is a network extender using VDSL2 Technology, it isn't suitable for using to connect to PSTN services. They are sold in the UK by Black Box Network Services. They're a fairly niche product, I've used similar where new fixed wiring or infrastructure isn't possible but a WAN /LAN needs extending to a remote location. My personal recommendation would be to use quality PoE breakout boxes, (i.e. not £10 'value' kit from Amazon) together with your existing VDSL2 modem.

Edited to add:-
http://cpc.farnell.com/stontronics/t4969st/12w-power... appear to be reliable and suitably rated.

Edited by deleted (Mon 16-May-16 19:57:50)

I've used a passive injector/splitter with the Standard PSU in my old house and it worked fine but that was over a fairly short run, 12v drops off quite quick over POE.

I have a RB450 Atm that's being powered by 12v from an ER-X , seems be getting about 10v after losses in the cable (not with the stock PSU but a higher rated one) At some point I'll get around to giving it 24v instead.

In reply to a post by 10forcash:

The 'Yoda' device is a network extender using VDSL2 Technology, it isn't suitable for using to connect to PSTN services. They are sold in the UK by Black Box Network Services. They're a fairly niche product, I've used similar where new fixed wiring or infrastructure isn't possible but a WAN /LAN needs extending to a remote location. My personal recommendation would be to use quality PoE breakout boxes, (i.e. not £10 'value' kit from Amazon) together with your existing VDSL2 modem.

Edited to add:-
http://cpc.farnell.com/stontronics/t4969st/12w-power... appear to be reliable and suitably rated.

Quite right - thank you. The fact this simple splitter exists is probably the main reason nobody has bothered with making a PoE powered VDSL2 modem - I suppose there is not much demand for them.

Another vote for using a break-out box.

The 'yoda' device is the sort of thing used by firms to join two buildings on a large industrial site where they have their own twisted pair network already there that is not part of the usual telephone network.

In reply to a post by drinahn:

The fact this simple splitter exists is probably the main reason nobody has bothered with making a PoE powered VDSL2 modem - I suppose there is not much demand for them.

Possibly more to do with the current limitations inherent in PoE, most modems need around 1A @12VDC or thereabouts, which for the vast majority of standard kit is about the safe limit per port.

The volt-drop of the length of Ethernet cable may be enough to allow the normal modem to work at 12V, if 24V was feed from the POE switch.

I will do some tests on my POE access point when it comes that I have just brought.

Volt drop doesn't work like that. 100 metres of CAT5 / 5e has a loop resistance of ~20 Ohms per 100 metres (of course, the maximum permitted run between ports is 91 metres in the CAT 5 / 5e specification). Given that the modem doesn't draw a constant level of power whilst in operation, it would be impossible to regulate the upper voltage limit with a fixed length of cable (for an explanation of this, see Ohm's Law). In addition, the cable would need to be longer than the maximum data transmission limit given the port power output of 15.40W as specified within IEEE 802.3af - and make the wiring quite warm too.
See http://www.belden.com/docs/upload/PoE_Basics_WP.pdf

Edited by deleted (Wed 18-May-16 18:50:54)