g.Fast in the countryside

First off I know what a g.Fast pod looks like having seen loads on cabinets on the Bridgeton exchange in Glasgow. So a couple of weeks ago I was driving in Dundee and notice a few g.Fast cabinets. A quick check on Streetview suggest for example that cabinet 26 on Brook Street is one. Rather odd because Dundee is not on the list of places to be getting g.Fast.

So today on my way home I stopped off to get some milk at the Coop in Tayport. It just happens to be right next to cabinet number two for the Tayport exchange (ESTAY), and blow me down it's not sporting a g.Fast pod. Now Tayport is as things go firstly in the countryside, secondly small, according to SamKnows supports about 1900 residential properties and approx 50 none residential properties. It also only has to the best of my knowledge four cabinets. Three original ones, and a more recent BDUK one at the exchange to deal with exchange only lines. This has the number four stenciled on and being recent is presumably the highest numbered one.

This of course prompted an immediate trip around the other cabinets which reveals that one, two and three are all supporting g.Fast pods, but the brand new one at the exchange (number four) is as of yet not.

A quick check on the BT Wholesale checker, and there is no g.Fast availability on my line, but I know on the Bridgeton exchange in Glasgow it took some pods best part of a year to show availability. I guess it's possible that I am too far away, but then again I currently sync at something around the full 80/20. Though for reasons I don't understand the HG612 is reporting much higher SNR, attenuation and power down than up. Specifically I get speed 77.50/22.98, SNR 12.50/2.6, attenuation 17.60/0.00, power 13.0/7.3. Anyway I am not entirely sure the route taken there is a pole in the back garden and the cable seems to go over the wall and into the ground in the church grounds. My guess it goes to one of the chambers in the footpath between the church and the cabinet (there are several), and is probably around 200m from the pole to the cabinet. So potentially in range of a g.Fast service. That said my guess is that only a small percentage of Tayport will be able to get a gFast service. Which makes the deployment of the pods even more strange.

Anyway does anyone know anything about these unadvertised gFast pod deployments? Also does anyone know when Openreach started deploying g.Fast outside cities?

Finally for anyone who thinks I am mistaken here is cabinet two on Streetview which quite old as it does not show the VDSL fibre twin.

https://goo.gl/maps/QV1cAHEA9hv

Here is the photo I took today of the same cabinet. It has now been reskinned, and supports a fibre twin in addition to the gFast pod.

https://small.buzzard.me.uk/stuff/tayport2_gfast.jpeg

https://labs.thinkbroadband.com/local/broadband-map#... shows a few more rural location pods too

So you don't have to be in a city though so far the majority is.

It's very odd if an HG612 is reporting an upstream sync of 22.98Mbps.

Are you looking at the GUI or the telnet figures?

Edited by RobertoS (Sun 07-Oct-18 17:36:47)

Here is the truncated output of xdslcmd info --show. What I don't understand is max downstream is 77264 Kbps, but the downstream rate on bearer 0 is 79999 Kbps. How does that work. It's Huawei cabinet.
# xdslcmd info --show
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 22974 Kbps, Downstream rate = 77264 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 2.6 12.6
Attn(dB): 17.6 0.0
Pwr(dBm): 13.0 7.3

In reply to a post by jabuzzard:

Anyway does anyone know anything about these unadvertised gFast pod deployments? Also does anyone know when Openreach started deploying g.Fast outside cities?

Openreach do intend to cover up to around 6 million premises with G.fast by 2020. This has recently been scaled back from 10 million as they have decided to focus more on rolling out FTTP (going from a target of 2 million to 3 million).

There are no announcements to where they are currently deploying this technology besides pilot areas. But as someone who is not in a pilot area, I can confirm that they are in fact rolling out G.fast outside of cities as I have seen quite a few cabinets with pods fitted and, in some cases, reshelled prior if necessary. I am in an area that had FTTC as part of BDUK, so I was surprised to see any commcercial interest in the area. Unfortunately, it can take a long time to actually enable the pods since cable links need to be upgraded.

I am not fully aware of everything what would make an area a good candidate for G.fast, but I imagine that having dense premises is preferable to maximise the premises covered with G.fast. Since G.fast uses 19-106 MHz as opposed to the approx 0.14-17 MHz that VDSL2 17a uses, the distance is a limiting factor; it is said to be around approx 370 meters before the speed drops off below 100 Mbps (at which point ISPs won't sell it to you as far as I know). But I would say at the top-end of the distance the upload is likely going to be noticeably less than with FTTC/VDSL2 17a which is currently employed.

In reply to a post by jabuzzard:

Here is the truncated output of xdslcmd info --show. What I don't understand is max downstream is 77264 Kbps, but the downstream rate on bearer 0 is 79999 Kbps. How does that work. It's Huawei cabinet.
. . .
Max: Upstream rate = 22974 Kbps, Downstream rate = 77264 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 79999 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps

The max rate is simply what the modem believes the line would be capable of at the current target SNRM. The max rate for the downstream is less than the current because the conditions would not favour a high downstream speed if a resync took place.

Anyway, your upstream rate is 19999 Kbps, therefore essentially 20 Mbps and not almost 23 Mbps. Though the indication is, as mentioned above, that modem thinks it could achieve almost 23 Mbps at the current target margin if there was no cap.

Edited to fix typo.

Edited by deleted (Sun 07-Oct-18 21:10:37)

Ah, that makes more sense .

Bearer 0 is your actual sync speed. Max (attainable) is what your line could theoretically reach if it wasn't capped at the Openreach product limits of 80/20.

The presence of Bearer 1 shows that G.INP is active, with more details in the parts you have cut off. It shows as 0 speeds as what the stats show is rounded to kbps, but Bearer 1 connects at 200bps.

So you are connected at the full 80/20.

Note that the SNRM figures are Down/Up, the opposite of the speed ones. We would need to see the same stats taken immediately after the next re-sync to see what their targets are, but the fact that your Max Attainable down is so much lower that Bearer 0 shows that considerably more noise is present than was the case when you connected. The upstream on the other hand is remarkably high but not a problem at this stage.

(Note, never use the HG612 GUI for stats in you think of doing so. The three lines in the GUI for SNRM, Attenuation and Power have one line of figures omitted and one duplicated, whilst the labels appear correct).

Edited by RobertoS (Sun 07-Oct-18 20:14:46)

In reply to a post by RobertoS:

Bearer 0 is your actual sync speed. Max (attainable) is what your line could theoretically reach if it wasn't capped at the Openreach product limits of 80/20.

In this case, yes, as the sync speed is already max of what the product allows. Although the max attinable can be applied to any connection regardless of whether it is at the cap or not. It's just a theoretical max that the modem thinks is possible with current conditions and parameters.

With interleaving in place, the case is slightly difference. As j0hn83 would say:
The max attainable is exaggerated with interleaving.

As someone who bounces around Dundee and Perth a lot. I can say that Perth had gfast pods fitted around 6 months ago. The gfast cabinets in Dundee have only appeared in the last month or so and seems to have included almost every PCP in the city centre although I have seem some in outlying areas too.

As you say there is no mention of gfast on the checker although I did spot a gfast record showing "planned" for another area of the city but I can't remember what the postcode was.

There is also a flurry of FTTP happening in rural areas too which seems to be also "off the record"

I was replying to the specific case, and the specific question and the poster�s misunderstanding of the basic meaning of �Max� that led to the telnet stats being posted.

Though for reasons I don't understand the HG612 is reporting much higher SNR, attenuation and power down than up. Specifically I get speed 77.50/22.98, SNR 12.50/2.6, attenuation 17.60/0.00, power 13.0/7.3.

Seeing as you seem to think I gave insufficient information about the general case, you forgot to point out that on FTTC, interleaving without G.INP active also lowers the sync speed and adds at least 8ms to latency. That the removal of interleaving raises the sync at the same time as it lowers the attainable and removes that additional latency.

Plus of course G.INP does have a small amount of interleaving, but without adding to latency and without �exaggerating� the attainable. It also has an even lower amount of interleaving on Bearer 1.

Various other difference can be seen with the full stats of course, particularly wrt G.INP. As I haven�t covered them, perhaps you would like to.

Edited by RobertoS (Sun 07-Oct-18 23:06:33)

In reply to a post by RobertoS:

I was replying to the specific case, and the specific question and the poster�s misunderstanding of the basic meaning of �Max� that led to the telnet stats being posted.

Yes, I can see the intention now. I was initially unsure of whether it was intended as a specific or general response. Because of forward thinking, I decided to employ clarity in a general case in case there is a misunderstanding if this thread is stumbled upon in the future. Perhaps unnecessary, however.

In reply to a post by RobertoS:

Seeing as you seem to think I gave insufficient information about the general case . . .

That is not the case at all, but rather an assumption of yours. In reference to the interleaving, I even thought this information would be a bit unncessary at the time, but I just wanted to quote a knowledgeable forum member but not go into much detail at the time myself. I understand you tried to make light out of the situation in the form of a cheeky jab, which is fine. But you should know that I am not doubting your knowledge but rather just trying to aid clarity.