HG612 faster than HH5

I was predicted 11.4-17.2 down (mbps) at order for FTTC. Yes, fairly low but the line length is about 2k. I previously got 7.1 Mbps over ADSL max, but mainly wanted the increased upload. The PCP wires only install happened and the initial speeds were around 9/1 (down/up). I was expecting higher, but was fairly satisfied. But then the upload speed dropped to 0.5 mbps with the upstream SNR going to 15db a few days later.

On recommendation, I purchased a HG612 as my cabinet is Huawei and after hacking it and plugging it all up, I got...11/1.1. I've heard various suggestions about why this is happening from interleaving effects to fortnightly reset of the HH5 causing the MSAN to think fault. But surely this can't be right? The HH5 is BT's flagship home router/modem/gateway? The hack is just to gain access to the interface, it's not an updated firmware.

HH5: IP Profile 8.57mbps
HG612: IP Profile 11.03 mbps. ftp://pedrosmisctech.zapto.org/xdsl.JPG for detailed stats fromt elnet

Once again today, I decided to swap around the modems and the HH5 immediately started connecting at 9mbps max, with about 8 real, whereas the HG612 despite many many reboots by this point was still happy to connect at 14 max, 11 real.

Edited by deleted (Sat 10-Jan-15 22:52:42)

Do you think it's down to differences in the chipset used, one being Broadcom and the other Lantiq?

Broadcom chips are allegedly the best, but BT doesn't want its customer to get too far below the estimate I would think. I had planned to test this on someone who was predicted a solid 80, but gets 65 to see if it helps on shorter lines...but lest I didn't have the time.

Apparently BT are currently implementing PhyR, a Broadcom invention.

Every modem will be slightly different - the complex termination impedance can effect the level of received signal and thus the signal available to the demodulator.

I have both Huawei and ECI modems here and speeds vary by several Mbps. You could get another HH5 and find it syncs faster and another HG612 which syncs slower.

Openreach are also implementing ReTx from this coming Wednesday, it will be rolled out presumably as a firmware update to the cabinets. Might help people with longer lines. Although is PhyR a brand name for retransmission? I guess it probably is.

Edited by deleted (Sun 11-Jan-15 13:12:40)

In reply to a post by Icaras:

Openreach are also implementing ReTx from this coming Wednesday, it will be rolled out presumably as a firmware update to the cabinets. Might help people with longer lines. Although is PhyR a brand name for retransmission? I guess it probably is.

And the relevance to this thread is ... ?

What is ReTx?

In reply to a post by Icaras:

Openreach are also implementing ReTx from this coming Wednesday, it will be rolled out presumably as a firmware update to the cabinets. Might help people with longer lines. Although is PhyR a brand name for retransmission? I guess it probably is.

really?

ReTx is physical retransmission (aka PhyR). I don't know where or how someone here found out that it would be Wednesday, but I'll be keenly watching my local cabinet for G.INP to be enabled on that day. Most probably isn't a firmware update that's needed, but a change of settings on the DSLAM (or profiles on the DSLAM). I presume G.INP will be enabled on all VDSL2 connections by default, this would make sense imo as it's a dynamic form of interleaving/error correction - unlike the current traditional one at the moment.

Anyway, that's all of the off-topic from me.

I was surprise MrSaffron haven't reply yet over Openreach wednesday RxTx roll out?

Edited by adslmax (Mon 12-Jan-15 16:41:54)

It is called lets see if it happens rather than spread rumours that disappoint people

Some info here: http://forum.kitz.co.uk/index.php?topic=14867.0

Yeah, it's now confirmed that a rollout is starting as of today [1].


[1] http://forum.kitz.co.uk/index.php?topic=14867.msg277...

A little bird has told me that if you are using an ECI modem, this will require a firmware upgrade to allow ReTx to happen, this upgrade is triggered by a DLM reset .........

Interesting. So does this mean those on an ECI modem will be stuffed and need to call out an engineer for a DLM reset?

In reply to a post by MHC:

In reply to a post by Icaras:

Openreach are also implementing ReTx from this coming Wednesday, it will be rolled out presumably as a firmware update to the cabinets. Might help people with longer lines. Although is PhyR a brand name for retransmission? I guess it probably is.

And the relevance to this thread is ... ?

No idea, ask the other guy. I was trying to respond to another poster who mentioned something similar.

What I would also add is that my understanding is that it won't be enabled on all connections, rather it'll only be turned on when it is needed and will be part of a profile.

Edited by deleted (Mon 12-Jan-15 20:19:03)

I see, well I hope it replaces the standard interleaving somewhat, and not adds to it. I guess BT have their reason for making it part of DLM, but it seems silly to me. Well, if it discourages banding and standard interleaving methods as much then I still see a point to it.

I imagine this also means many people won't notice any changes yet until DLM makes any changes again.

EDIT:
Looking at the latest SIN 498, I believe this replaces the standard interleaved profiles, which makes sense. The other possibility is that retransmission either is a middle option between fastpath and interleaved, or that retransmission replaces fastpath and interleaved remains for those connections which perform considerably poorly.

Also regarding those on an ECI with old firmware, from what I read on another forum thread (here) - those won't be able to sync but it'll be considered a fault still. This means DLM should be reset so that the ECI can sync again and then at the same time will download the new firmware. I'm not sure about those who have unlocked ECI's such as me - the BT agent might be disabled unfortunately.

Edited by Ixel (Mon 12-Jan-15 23:00:36)

Pass ?!?!

I daresay there'll be some form of work around.

It's ok, already know the answer . Edited my post above.

Note that PhyR is proprietary to Broadcom, while G.INP is ITU-standardised. ReTx seems to be the parameter name used by BT to control G.INP being turned on.

In reply to a post by Ixel:

Looking at the latest SIN 498, I believe this replaces the standard interleaved profiles, which makes sense. The other possibility is that retransmission either is a middle option between fastpath and interleaved, or that retransmission replaces fastpath and interleaved remains for those connections which perform considerably poorly.

My (desperately limited) understanding of G.INP is that there are some modes where it does affect latency for every packet (rather than just the ones that get re-transmitted), although less than interleaving does. I read this was related to the ability to reduce jitter, but haven't been able to confirm that this feature exists, or to see how it works.

If that is true, then I could see why DLM would want to maintain a "clear" fastpath as the default setting.

G.INP may still not be enough for a troublesome line, so the traditional FEC/interleaving solution will still be available, but now only as a second line of defence - with banding dropping down to a third line.

More info here, though it is in the form of a sales pitch for Assia's own DLM tool:
http://www.assia-inc.com/products-services/pdf/DSL_E...

So what does this mean for a person with perfect line stats?

I guess not much.

Yeap not much, and Openreach are still looking to see if they have launched this change that people are saying they have launched

Not much, as G.INP will likely be disabled for perfect connections and most likely only used as a first choice by DLM in an effort to improving lines which don't run as efficiently without it. I'm imagining nobody will notice G.INP on their line until DLM makes a change to that profile at some point in the future - including those who are already interleaved and stuck.

Edited by Ixel (Tue 13-Jan-15 21:53:08)

Openreach don't know if they've launched it? Haha, that sounds funny .

None of the xDSL stats have really changed so far...

I'm considering getting another HH5, even if it's just to use it as an AP.

In reply to a post by MHC:

Every modem will be slightly different - the complex termination impedance can effect the level of received signal and thus the signal available to the demodulator.

I have both Huawei and ECI modems here and speeds vary by several Mbps. You could get another HH5 and find it syncs faster and another HG612 which syncs slower.

Would that explain why my SP08 firmware unlocked HG612, I have noticed my upload sync is @ 15.35, yet with the BT HH5 it's @ 17.89. So technically I'm losing 2mb of my upload on the HG612.

I took off QoS as well, but should I consider trying the older SP10 and kill BT agent via Telenet as the SP08 is disabled by default in the WAN options?

You are not actually losing 2Mbps as it is not there to use. Every modem will sync at a different speed - you could get anoth pair of HH5 and HG612 and they could be te other way round.

QoS and BT Agent do NOT affect sync speed.

In reply to a post by MHC:

BT Agent do(es) NOT affect sync speed.

Oh really? What does it do then?

In reply to a post by BatBoy:

In reply to a post by MHC:

BT Agent do(es) NOT affect sync speed.

Oh really? What does it do then?

It uses some of the available bandwidth. There could be hundreds of small ISP or manufacturers monitoring applications running - they would still NOT alter the sync speed.

In reply to a post by MHC:

In reply to a post by BatBoy:

In reply to a post by MHC:

BT Agent do(es) NOT affect sync speed.

Oh really? What does it do then?

It uses some of the available bandwidth. There could be hundreds of small ISP or manufacturers monitoring applications running - they would still NOT alter the sync speed.

I think you're still on about QOS. I'm asking about BTAgent.

So where does it get any bandwidth from?

In reply to a post by MHC:

So where does it get any bandwidth from?

What BTAgent? Who said anything about bandwidth?

In reply to a post by MHC:

You are not actually losing 2Mbps as it is not there to use. Every modem will sync at a different speed - you could get anoth pair of HH5 and HG612 and they could be te other way round.

QoS and BT Agent do NOT affect sync speed.

mmm?

So why does http://speedtest.btwholesale.com/ always report my upload with the HH5 at roughly 17.28Mbps every time but the HG612 it's always around the 15.75Mbps mark? Ookla speedtests are always lower with the HG612 also.

I never get anything over 15Mbps using the HG612 and when monitoring upload speeds to BT cloud for example, I lose between 170-200/Kbps compared to the HH5.

Edited by deleted (Fri 20-Feb-15 17:13:02)

Do you understand the points made in the post you originally replied to?

When you understand about termination impedances and how they can affect signal levels and the input level to the front end of a demodulator along with the characteristics of a demod then you will realise why different modems will sync at different speeds.

Well when they roll it out 100%

I'm hoping to hear of a 120/30 FTTC package coming soon.