Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[kitz]

Interesting article about copper/cable, vectoring and g.fast

http://www.businessspectator.com.au/article/2013/11/15/technology/why-copper-isnt-going-away-hurry?utm_source=exact&utm_medium=email&utm_content=512476&utm_campaign=ts_daily&modapt

[JGO]

As you say, very interesting.  They haven't come up with a processing solution to copper theft though !

[Black Sheep]

Good news for us 'Field guys'. 

The odd thing is, according to some of our esteemed colleagues on this forum, 'Vectoring' is old hat. It's been around for years and everyone in the world bar BT knows it works, and as such, why are BT taking so long trialling it ?? etc etc etc ……
 
Reading that link, it would appear its pretty much in its infancy with Telco's and not all the trials went swimmingly ?? Another example of individuals mistakenly seeming to know more, than the actual industry experts.

[Bald_Eagle1]

Reading that link, it would appear its pretty much in its infancy with Telco's and not all the trials went swimmingly ?? Another example of individuals mistakenly seeming to know more, than the actual industry experts.

Perhaps if various arms of BT were somewhat more open & transparent for the benefit of the no doubt tiny minority of EU's who are actually interested in such matters, there would be far less assumption, supposition & outright wrong conclusion drawing?

It would also perhaps not be too bad an idea to occasionally filter some details down to the 'Field guys' as I'm sure it would help for whenever they end up visiting an 'interested' EU.

FWIW, here's a couple of examples of when significant changes to service were implemented that caught EUs (& apparently ISPs) by surprise (including Plusnet - actually owned by BT):- 

*Change from 8c profile (Max DS sync speed 40 Mbps / US sync speed 10 Mbps) to 17a profile (Max DS sync speed 80 Mbps / US sync speed 20 Mbps)
*Revision of 17a DS band plan tones from Maximum of 1939 to 1959 (Huawei DSLAMS)
*Very recent HG612 modem firmware updates, including revised band plan tones & apparently switching SRA on (Seemless Rate Adaption)

 

[waltergmw]

Gentlefolk,

Did not some of our esteemed cognoscenti suggest that vectoring is not directly compatible with the MSANs installed ?
I thought it had been suggested that Huawei MSANs require an additional module installed and ECI ones require a new processor board.
All of which would be relatively expensive and time consuming.

Whilst I'd be surprised if laboratory testing data was not employed by some marketeers, it seems there are others who are yet to be convinced that it is the answer to BDUK's prayers.

https://neil-fairbrother.squarespace.com/blog/2013/7/1/gfast-a-high-speed-cul-de-sac

Kind regards,
Walter

[burakkucat]

I thought it had been suggested that Huawei MSANs require an additional module installed and ECI ones require a new processor board.

Before vectoring can be implemented:

• "Hauwei cabinets" will need to be fitted with a MA5603 sub-rack.
• "ECI cabinets" will need to have the existing M41 MSAN removed and replaced with a V41 MSAN.

Not something that can be done without cost nor without disruption to existing services. 

[kitz]

M41 MSAN removed and replaced with a V41 MSAN.

Its not impossible to do vectoring on the M41, as its done on the line card.
The problem with vectoring at the line card is that all lines from the pair feed must be vectored and you cant mix and match the pair feeders.

The V41 is a 'shelf based' vectoring solution which has a dedicated card responsible for mapping any pair feed to any of the line cards.  The V41 is a more efficient solution.

Shelf-based vectoring solution
 
A shelf-based vectoring platform is the preferred solution for the deployment of dynamic high-speed access networks. In such a vectored VDSL2 platform, the vectoring engine resides on a dedicated service card that controls the vectoring activity of all the VDSL2 line cards. Connect any card to any pair in any feeder!

In this case, the vectoring engine card controls ECI’s four 64-port VDSL2 line cards, without compromising performance or capacity.

Most VDSL2 vendors who have developed vectoring solutions have implemented them on a per-card basis. The vectoring engine resides on the VDSL2 line card and controls the vectoring activity on the ports of the line card. This approach has two drawbacks:

    Vectoring requires significant processing power and memory resources. These resources are allocated from the ports and may force the operator to reduce the number of ports deployed or accept a traffic performance hit.
    The card-based vectoring approach requires that all the pairs in a feeder cable be connected to the same card; if not, the vectoring engine misses out on crucial measurements and the subsequent pre-coding that ensures the efficiency of the vectoring operation is compromised. With typical feeder cables containing 100 pairs or more, this approach is highly impractical. In addition, as customers churn, card-based vectoring requires significant cable management activity, with all the relevant opex implications.

Source ECI blog

As an aside I just checked the model no of 'my dslam' which is an ECI M41A and uses ECI VTU C-64 line cards.

[burakkucat]

b*cat performs his best Japanese-style bow to acknowledge Our Leader's findings. 

It has been quite some time since I last "had a fight" with the ECI web-site when trying to find some information. 

Now I wonder what choice Beattie will make for her "ECI Cabinets"? 

[kitz]

I found it by searching "ECI, vectoring, line card", as Id heard before it was possible, but it wasn't always practical as ports/pairs may be wasted. 


>> Now I wonder what choice Beattie will make for her "ECI Cabinets"?

I suppose it depends how much and how often they want to avoid this :-

It becomes necessary to send technicians to the street cabinet to perform some cable management.

Its a shame theres no module that could be slotted in to the existing M41s rather than having to replace the whole dslam. 
If anyone had the weight to get ECI to provide such a thing then youd think it would be BT...  but since theres no news on this front I assume that its not possible.

Theres an awful lot of ECI cabs out there that are going to need to be upgraded 

[burakkucat]

Theres an awful lot of ECI cabs out there that are going to need to be upgraded 

Nods in agreement. 

[ryant704]

If this is the case, wouldn't it be cheaper for OR to roll out 30a and Vecotring in one big go?

[waltergmw]

@ Ryant et al,

I don't think we always observe a rational approach to costs as Peter Cochrane remarked in the comments to Neil Fairbrother's article I referenced above **

Perhaps of more concern are some more fundamental considerations:-

1.  the ever-increasing complexity and continuing development / experiment with "the wrong technology"

2.  the capacity and the capability of the work-force to maintain, let alone upgrade this technology. It is one thing to get subcontractors to install shiny new cabinets (once they've established which way round to re-sleeve a PCP˘˘) but entirely another to dismantle and then re-engineer and re-test the operational equipment therein and every service so connected.

˘˘  http://www.scribd.com/doc/97538956/Reversed-PCP-5352

Just as very simple and trivial examples, all Ewhurst FTTCs were installed as ECI 128s but with only a single 64 way line card installed. Two of the three FTTCs have now been unavailable for service on THREE occasions and the last once for the second line card, all within 12 months of their installation.

a)  to install a second 64 way line card
b)  to re-excavate the ducts and add a joint pit to install a 50 pr and then a 100 pr in one cabinet and a 100 pr only in the other cabinet (so that's still leaves another 50 pr missing)
c)  in one cabinet only so far, installing additional telco jumper cables, IDC connector blocks and then connecting the additional tie cables. This operation left that cabinet unavailable for over 80 days.
This is just in one village (and outliers) of around 900 properties. Even if you allow for this being an early-learning development###, can you even contemplate the effects over the whole of semi-rural UK ?

###Openreach contractors as of last week were STILL installing a Huawei 288 cabinet requiring 3 sets of 100 pr tie cables with a single curved duct run of over 50 m without a pulling pit.

http://www.scribd.com/doc/185060191/Albury-PCP-4-7149

Now contrast that budget-constrained engineering with the sums being speculated on BT sport which cannot possibly be made available to all - assuming they want it !

Kind regards,
Walter

_____________________________________________________________

** All this was so obvious way back in 1986....but 'real engineering and economics' has been driven out of the telecoms industry. You can't beat physics (loss and crosstalk) and you can't stop Moore's Law! Mini-DSlams are an insane option! To get network reliability and resilience you have to take out electronics not put more in! To get a 'Green Network' you have to reduce the amount of material used and energy consumed! And Mbit/s are not enough for an obvious future rushing towards us. We have to start talking Gbit/s. But if you want sub-optimal industries and a population who just sit and watch sport on TV....just keep installing copper!

With a copper network you need over 6000 switch sites in the UK. If you install optical fibre this number drops below 70. 20,000 man in van crews goes down to 1,000, and all water ingress related faults just go away. Now redo the economic argument. Go figure!

Peter Cochrane

[kitz]

If this is the case, wouldn't it be cheaper for OR to roll out 30a and Vecotring in one big go?

TBH Im not sure what changes would be required for 30a..  and even if 30a would be beneficial aside from those very close to the cab, so Im not sure what % would gain from 30a.
I would have thought vectoring though would bring benefits to more of the population?  Particularly when we on this forum are beginning to see very large decreases of speed (circa 15Mb) once the cabs start to fill up.

According to Asbokid and discussions in this thread, the Huawei's just need a firmware upgrade for vectoring. 
A very quick scan shows mention of a sub-rack and ignitionnet mentions cable re-arranging for 30a. 

I dont have time to do any digging but perhaps in the Huaweis there is an easy 'slot in' type card that can do this?   Kind of like sticking a sound card into a PC?  I dont know, so if anyone has time to do a bit of research then please do share.

I'd already mentioned above that its seems to be a failure of the M41's that you cant just slot in new modules.
The V41s should already be compatible with 30a and bonding.

The question remains how BT will handle the ECI cabs.  Will those users get line card vectoring and BT burden themselves with juggling copper pairs, or will they stump up and get V41s.  Only they will know the costings.

[kitz]

@ Ryant et al,

I don't think we always observe a rational approach to costs as Peter Cochrane remarked in the comments to Neil Fairbrother's article I referenced above **

The Peter Cochrane situation has been discussed many times.  Latest here.


At the end of the day Peter Cochrane (who earns his living by recommending & consultant of FTTP) of course is going to say FTTP.   
Just as Norbert Reithofer wouldn't recommend a Ford Focus. 

What Peter Cochrane fails to take into account is where the billions of pounds to fund it for the UK is going to come from.   
Years old estimates stood at 18 billion to cover just 80% - leaving out the more costly to provision 20%.   
I more recently saw a figure of 90 billion mentioned and that doesnt cover the harder to reach areas.   
We arent a tiny 9x4 island like Jersey whose gov can afford to fork out 20 million (and give Cochrane a chunk of Ł whilst their at it too).


90 billion is near approaching whats spent in total on the NHS including staffing, fatcat salaries, prescriptions, treatments, hospitals the whole lot.
Yes I'd love a BMW, but economics mean I have to stick with my Vauxhall :/
I honestly have no idea where the funding for FTTP would come from.

[c6em]

....and to all those who now complain why did not BTOR install cabs with vectoring capable line cards etc inside them from the start....

You need to ask yourself would you have been happy for YOUR cabinet not to have been done at all because the costs of everyone else's cabinet was going to be higher because of the more expensive vectoring-capable-cards.
So YOUR cabinet gets nothing as there is no more money for it.
There would have been screams of outrage on TBB, here, ISPreview and the rest on how we don't care about some tech in the future we just want better speeds 'now'.

I wonder if I should apply for Liv Garfield's job now that she is moving on......?