Kitz Forum

Broadband Related => Broadband Hardware => Topic started by: chrisandrews90 on September 23, 2021, 11:15:09 PM

Title: Asus RT-AC86U with BT Infinity
Post by: chrisandrews90 on September 23, 2021, 11:15:09 PM
Hi all,

I just purchased an Asus RT-AC86U to replace my BT SmartHub2. I have also purchased a brand new Openreach branded ZTLink MT992 modem to use as a bridge. I only have BT Infinity 2 as that is the fastest speed I can get in my area currently.

I have connected the modem to my phone line which has a filtered faceplate, connected the modem to the router via the WAN port, and then completed the setup on the router, putting it in wireless router mode, and inputting the BT ISP settings (PPPoE, bthomehub@btbroadband.com and BT as the password) but all I get it the LAN light being red on the router. If I put the router in AP mode, all lights go green but I have no connection.

Is it the modem causing issues as it is isn't compatible with my cabinet or because it is a g.fast modem? Do I need another modem or am I missing something completely obvious? Any help appreciated!
Title: Re: Asus RT-AC86U with BT Infinity
Post by: burakkucat on September 24, 2021, 01:14:52 AM
Welcome to the Kitz forum.  :)

I just purchased an Asus RT-AC86U to replace my BT SmartHub2. I have also purchased a brand new Openreach branded ZTLink MT992 modem to use as a bridge. I only have BT Infinity 2 as that is the fastest speed I can get in my area currently.

<snip>

Is it the modem causing issues as it is isn't compatible with my cabinet or because it is a g.fast modem?

I strongly suspect that the modem is the problem. I am not aware of anyone successfully using a MT992 for a VDSL2 based service.

A G.Fast service makes use of time division multiplexing (https://en.wikipedia.org/wiki/Time-division_multiplexing) whereas a VDSL2 (or, more generally, any xDSL) service make use of frequency division multiplexing (https://en.wikipedia.org/wiki/Frequency-division_multiplexing).
Title: Re: Asus RT-AC86U with BT Infinity
Post by: hushcoden on September 24, 2021, 08:28:59 AM
Looking at the modem spec, it states it's also VDLS2 compatible with profiles 8a, 8b, 8c, 8d, 12a, 12b, 17a

I found this post https://forum.kitz.co.uk/index.php?topic=24240.0 who might help, good luck !
Title: Re: Asus RT-AC86U with BT Infinity
Post by: meritez on September 24, 2021, 08:48:13 AM
Looking at the modem spec, it states it's also VDLS2 compatible with profiles 8a, 8b, 8c, 8d, 12a, 12b, 17a

I found this post https://forum.kitz.co.uk/index.php?topic=24240.0 who might help, good luck !

But that's a huawei mt992, not the ztlink mt992.

I'm not sure the ztlink version supports anything but g.fast

Title: Re: Asus RT-AC86U with BT Infinity
Post by: hushcoden on September 24, 2021, 10:16:03 AM
But that's a huawei mt992, not the ztlink mt992.
For what I can read online, they are the same

Quote
I'm not sure the ztlink version supports anything but g.fast
That's most likely the case - I wouldn't be surprised if Openreach 'hacked' the firmware to allow g.fast connection only
Title: Re: Asus RT-AC86U with BT Infinity
Post by: j0hn on September 24, 2021, 11:05:31 AM
An MT992 for VDSL (even if it worked) is overkill.
The cost of the units are astronomical, providing zero benefit over a standard VDSL2 modem.

They are completely locked down so stats can't be gathered. You can't even login to check if it's synced.

I've no idea if the MT992 is configured by OpenReach to operate a VDSL2 service. It would have no real benefit over an OpenReach branded £10 Huawei HG612.

Just be careful with the testing.
If every time you are trying to connect the MT992 it does actually achieve a connection (sync) with the cabinet then you may well end up capping/banding your own line.
The DLM will apply banding to lines that keep resyncing over and over. It can't tell the difference between you playing with hardware and a genuine line fault.

My advice would be to return the MT992 if possible.
Sell it if a return isn't possible.
Purchase a known good, reliable (and likely much much cheaper), bridge mode compatible VDSL2 modem.

The MT992 isn't future proofing anything.
If you don't have G.Fast available on your cabinet then it isn't coming. The G.Fast rollout is over.
Title: Re: Asus RT-AC86U with BT Infinity
Post by: chrisandrews90 on September 24, 2021, 12:41:34 PM
Thank you for that info j0hn. I bought the modem new for £10 off a guy local as I had thrown my old Openreach modem out years ago not thinking I'd need it...

I shall try sell it online and purchase the one you've recommended, I believe now it is the modem that is causing issues.

I shall report back with any new developments. Thank you to all who have responded so far, this forum seems really helpful!
Title: Re: Asus RT-AC86U with BT Infinity
Post by: j0hn on September 25, 2021, 11:42:51 AM
That's dirt cheap and will see a considerable profit on eBay.

I used a Zyxel VMG1312-B10A in bridge mode prior to switching to FTTP.
It's also an excellent bridge modem.