New router has ruined my Plusnet Fibre connection!

Ok, the title may be slightly overdramatic but if anyone can figure out what may have happened here I'd be very grateful. I recently purchased an ASUS DSL-AC56U for its QoS/Bandwidth limiting features. I set it up on Monday and at first there were no problems. The sync speed (37/10) was the same as it was with my Plusnet Hub One except 0.5Mb higher on the upstream. FastPath on both up & down & G.INP enabled.

Yesterday G.INP was switched off, interleaving turned on for the downstream and the connection dropped several times. Download sync speed reduced to 34.5Mb.

Today the connection was quite bad, it dropped several times, packet loss on the BQM and the download sync now reduced to 33.1Mb. Looking at the DSL stats the SNRm on the downstream was bouncing around between 1.8dB & 5dB. Also 10000s of CRC errors. No problems on the upstream which has remained stable and unchanged throughout.

I then plugged my PN Hub One back in which has synced up at 30.7/9.4, and rang Plusnet who are sending an engineer Friday because sync is below minimum guaranteed (34Mb). I am not sure whether to suspect the Asus router as faulty or a line fault. On the one hand I still have a slower sync speed with the Hub One, and with a SNRm of 6dB. I would have thought this noise margin should be higher as previously it was 6dB at 37Mb instead of the current 30Mb. On the other hand, it's not bouncing around like it was with the Asus router and is staying between 5.9 & 6.1.

Does anyone have any thoughts/suggestions?

Here are my BQM graphs for the last 3 days:
Monday (the large red part is when my IP address changed for some reason)
Tuesday
Today

Edited by deleted (Wed 03-Jul-19 15:13:12)

The ** Asus DSL range of modem/routers contain a Mediatek xDSL chipset.
I have never come across such a garbage DSL chipset that performs so poorly.

Frequently I see lines that were stable for years then suddenly they get hammered by DLM after switching to an Asus modem.

They are so bad OpenReach have blacklisted them from using G.INP as they don't follow the standards and it was causing issues with the fibre cabinets.

Changing modem will see G.INP return. It won't ever work with your Asus.

If you still can, return the Asus.
You could also use a separate modem and use the Asus as a router only.

** The newer Asus DSL-AC88U uses a Broadcom xDSL chipset and works flawlessly with G.INP.

Edited by j0hn83 (Wed 03-Jul-19 15:19:18)

Did Plusnet mention that there might be a charge if the engineer reports no fault found, or that it is/was with your equipment? I don't know if they still pass it on.

As it seems clear the problem was caused by your ASUS, your best bet would be just wait and see if it all returns to normal after a few weeks back on the Plusnet Hub.

Another problem could be that your line has now been banded. That can delay automatic correction. If you can get connection stats from the Hub then those can often give us a clue to whether or not that has happened.

Thank you both for your speedy replies. I wasn't aware of the Asus modem issues so that has given me food for thought. It was an Amazon purchase so I'm well within the return window if I need to send it back. I chose this specific router because I don't like unsightly external antennas on other models and because other brands such as TP-Link routers can't do bandwidth control on a per device basis, only traditional QoS.

I would be more than happy to use it just as a router but I have no idea which modem to buy. I'd even use the Hub One but AFAIK it can't be used in a modem-only mode, plus there are clearly better modems out there as even this Asus gave me the full upload rate of 10Mb which I've never seen with my Hub One in the 18 months I've had it.

With Plusnet when they book an engineer appointment you have to agree to the "engineer statement" that they read out before they will proceed, which includes a £65 charge if no fault found / fault in customer premises. Apparently £65 is only half the Openreach charge and PN absorb the rest. The problem I have is that I will be charged anyway if I cancel the appointment without giving 48hrs notice - impossible because the engineer is coming Friday.

To be honest I still think there is something going on as I think the SNRm should be higher than what it is given the lower sync speed. I've uploaded my Hub stats here but they are quite limited.

Edit: With regards to G.INP being blacklisted on some modems, wouldn't it just not turn on in the first place? It just seems strange how the connection initially worked well for a bit but then lost G.INP and went to pot after 24 hours.

Edited by deleted (Wed 03-Jul-19 16:35:14)

No idea, I just know OpenReach removed/blocked the Asus modems with Mediatek chipsets from using G.INP.

As far as I know it's the only modems they have done this with.

Swapping to a compliant modems brings G.INP back.

As for using the device as a router only, I wouldn't advise going down that route if it can be returned.
You need to use 1 of the Ethernet ports as a WAN port and the DSL modems are missing a couple features available on the RT variants.

In reply to a post by av709:

I have no idea which modem to buy

Personally I have been extremely happy with Draytek Vigor 130, although it's not the cheapest. It does baby jumbos so you can get 1500 byte MTU even over PPPoE, and does G.INP. Claims to support vectoring too, but my line doesn't have it.

The downstream sync and maximum don't look to me as though banding has been applied. Which is good news, as it's possible that by the time that engineer arrives DLM will have re-instated G.INP.

The bad news is that from what you say you are likely to have to pay the £65. Unless you are quite lucky. Or, if it was caused by the ASUS, and you had explained that it happened soon after you installed that, you might succeed in arguing that the support person should have thought of that before scheduling the visit.

In reply to a post by candlerb:

Personally I have been extremely happy with Draytek Vigor 130, although it's not the cheapest.

I bought one and it did worse to my line than the OP's ASUS seems to have done. I ended up with the line banded and it stayed so for many months at 55Mbps sync when it had always run at well over 65.

I did send the Vigor back a few days after discovering what it had done, and replaced it with a Billion 8800NL R2 modem/router. That stabilised everything, but the banding persisted.

In the end I managed to get DLM reset removing the banding, and over a short period got G.INP and a 3dB sync-time SNRM, taking me to sync's well over 70Mbps.

Note, the Vigor 130 does seem to give good results for most people, but I did find several who had the same experience as I did with it.

Value for money modem only wise IMHO the old Huawei HG612 3B (can often be got for £10-15 on auction sites) has always done me well on my connection and a few relatives.

A few people say they are old but they seem to give me a very stable sync.

In reply to a post by candlerb:

In reply to a post by av709:

I have no idea which modem to buy

Personally I have been extremely happy with Draytek Vigor 130, although it's not the cheapest. It does baby jumbos so you can get 1500 byte MTU even over PPPoE, and does G.INP. Claims to support vectoring too, but my line doesn't have it.

The Drayteks I've installed are very good.
All their VDSL kit sold in the UK supports vectoring.

My old line didn't like the Vigor 130, (VM my ISP for now) I got the same symptoms that the OP is having with Asus, made my line really unstable and sync rate kept dropping.
I had joy with HG612 3b, Billion 8800NL R2 and TP-Link W9970......with the Billion and TP-Link set up in bridge mode to work as modem only and then plugged into my Asus so I could use the features like QoS for example.

Edited by deleted (Thu 04-Jul-19 10:20:19)

Thanks all for your replies. It looks like the router-only equivalent to my current Asus is the RT-AC56U which is now EOL, presumably succeeded by the AC57U? All the current models seem to have external antennas so I might just have to get over that. I think it would be better to return what I have now, because the router-only equivalent is cheaper due to the lack of modem, so I may as well put that saving into getting a separate modem or spending it on a better router.

Definitely very unsure now which modem to get if even reputable ones can cause issues on some lines. A BT OR modem does seem like a good idea. If it helps my cabinet must be Huawei as it has a Broadcom DSLAM as reported by the Asus. As a side note, I did have a TP-Link Archer VR600 V2 a couple of months ago that synced up at 40/10, but I sent it back the next day when I realised it couldn't do bandwidth control, so I've no idea whether it would have been stable at that speed.

In other news, it's been 24hrs since I plugged the Hub One back in, the connection has only dropped once but has synced up at an even slower rate (29/9.4) so either there is something else going on or DLM is still mad at me for using the ASUS! It'll be interesting to see what the engineer has to say about things tomorrow. I doubt I'll be charged a fee because they will find a fault - a small REIN issue that's been ongoing for years. I've traced it to the fluorescent lighting used in the shop below where I live and it does show up on Plusnet's GEA tests and the tests OR engineers do. Though it doesn't have a significant impact on my connection, I doubt they'd be able to prove that it wasn't that issue that's caused the problems I'm having now. At the very least I might get a DLM reset out of all this.

Can you post exact stats?
If the line is banded by DLM you can ask the engineer to reset the DLM.
His equipment would also sync at the banded rate (even their tests at the cabinet), that's hardly a fault in your property.

It would take a couple days (sometimes a few weeks) for G.INP to return if you got a DLM reset but as it takes the lines history in to account a reset would be best all round.

I wouldn't even mention the Asus to the engineer. They don't see what device was connected.

Edited by j0hn83 (Thu 04-Jul-19 15:02:37)

Remember folks - with the draytek's there are often several versions of modem code - you should check which ones where giving problems and maybe try one of the others.

I've had lines with issues and usually a switch of modem code fixes it.

Had that on a Vigor 2860ac at my sisters. Kept dropping the connection every few minutes. Had been fine on my line when I set it up. Switched from the BT SIN498 approved firmware to the Vector 4 firmware which going by the version numbers is quite a bit more recent. Line magically became stable, currently up 237 hours (I believe a thunderstorm power blip was the reason for the last reset).

Presumably the newer firmware has not been through BT's illegal approval process (BT are not approved by the EU for doing telecommunications approvals and you are not allowed separate country by country approvals for telecommunications equipment anywhere in the EU anyway. It's that thing called the single market) so they keep pushing the older version in the UK. I believe BT charge for their illegal "approval" process so hardly surprising Draytek don't keep getting each new version approved.

I am a bit surprised that they scheduled a visit without saying "see how it goes for a few days" - or does being "beiow promised speed" mean there are financial penalties for the ISP ?

I initially had 25 Mbps downstream (27.4 was the promise) but stuck with it as I was happy enough with that.

However, in September/October it went up to sync speed of 39.99 or 40 and since then I've had web pages not loading properly (perhaps linked to UDP packets being thrown away somewhere within the PN/BT network as my DNS lookups seem to be about 50:50 in terms of success, leading to half loaded pages, or not getting a video to start with 1 click on YouTube or NowTV etc.

Major nuisance but not related to the problems which the OP is having.

Well, I'm in trouble now. My connection has re-synced at 35/9.4 overnight which is now above the minimum guaranteed speed. With little signs of a fault it looks like I'll be charged for this.

The engineer can see previous sync speeds.
The line was below the minimum when the issue was reported.

Make a point of mentioning that to the engineer.

Engineer's just been. No fault found as expected but he's installed a new master socket, re-terminated some cables at a junction box and reset the DLM. Sync speed now 36/9. He's going to put on the notes "possible REIN interference at time of reporting". So it looks like Plusnet will be charged and they'll probably try and pass £65 on to me, so it'll be interesting to see how that discussion goes when the time comes!

Sounds good. You should get 40/10 sync back once G.INP kicks in, though that might be a week or two.

I would think that the work he did, plus the DLM reset which AIUI is normally only done after fault fixing, and that comment should keep you cost-free.

Let's hope so.