Future Telephony

[Bob Williams]

Something told to my grandson at work, by a BT Business tech guy, set me thinking. I found this:

https://tinyurl.com/y62mpmby

Then This:

https://tinyurl.com/y4vwx3ud

So it looks like 2025 will see the end of PSTN (analogue, Public Telephone Switching Service) to VOIP, or some form of that. Don’t know if I read this correctly, but that entails both telephone handset and wall socket connected to the BBand router, instead of separate connections for each to the BT wall socket, as at present. That is going to mean that everyone who does not have VOIP now, will need a new wall socket. Estimating the amount of money that will cost, is making my head hurt. BT will also have to provide the rural and other areas, which currently have below (say) 10Mbps bband downloads, with a compatible service. Oh really? In view of what happened to the Rural Broadband Initiative, I just don’t see that happening. 2015 is not that far away, BT and Openreach have not exactly made great progress with existing supply concerns.

When the Thought Police arrive at your door, think -
I'm out.

[dwynnehugh]

 

” …. that happening. 2015 is not that far away, BT a…..”

Sorry to burst your bubble Bob but 2015 has been in North Wales – perhaps we’re not that far behind the times after all!!!  LOL  ????????????

The more you meet people the more you understand why Noah took animals instead of humans

[JayCeeDee]

Having read the overview in the first link, I thought that less Urban areas might pose a greater problem to this as for it to work it would almost need fibre to the premises ( FTTP ) to all premises for any reliable VOIP to compete with the quality of copper wired telephony. We can all remember the quality of Skype calls.

However some research turned THIS  ( Download link ) up.

Interestingly, it seems that FTTC with cable TV lines ( fibre optic ) from the cabinet to the premises could give you 200Mb down with 70+ average down and 5+ up. Speeds some rural premises ( Bob?? ) would salivate over.

What’s needed for that is commercial interest in the DPA network ( page 7 on the document ) that is actually open to OR’s competitors, if they were only minded to take it up.

It’s going to be wait and see time for some years to come, but it was interesting to see that it’s possible to be done, providing the commercial will is there. Perhaps the VOIP will make it more appealing to the ISP’s or is that Line Rental ( approx £20 per month ) proving too tempting to forego??

[Dave Rice]

VOIP needs very little bandwidth, what it needs is priority – QoS.

Modern consumer routers can now accommodate this, even detect it from the default ports used, and IP TV which needs the same. I say “needs” they don’t, but it makes them less susceptible to delays from competing traffic. In the early days my ex B-I-L tried installing VOIP for an SMB customer and failed to understand this as he didn’t have a data networking background. This lead to him dismissing VOIP as crap, an attitude that’s plagued the switch from analogue to IP in so many areas.

In the home you don’t need to embrace VOIP and SIP (with it’s cost model for accessing POTS) to achieve the same result, but BT etc. aren’t going to tell you that – yet. Line rental? They’ll say you’ll still need a cable of some sort to the premises, the question is with competition from 4G / 5G will they / how will they disguise the cost you don’t need to pay? They will play on the ignorance of the customer for sure. We’ve seen that on another thread with Virgin exaggerating bandwidth requirements.

The router provided with the 3 HomeFi – the Huawei B311 – has an RJ11 socket to attach a POTS handset to. It’s what I intend to do, attach my DECT base station to it, but there are other ways to use your own POTS handsets in this way too. That means I need a phone SIM (for call minutes) and that’s now not a problem. Unlimited everything for £24.

So my old home phone will have a new “mobile” number but we’ll all be using our own phones with sufficient minutes – probably unlimited – so it’s not going to get used much. Probably use it as the “bucket” phone number and let the call minder deal with the spam calls.

QoS on the calls? Well they’ll be on the Three network as mobile calls, not VOIP, so I can’t see an issue. So connecting to whatever BT decide will be the national backbone won’t be my problem.

This is all making a 4G ISP solution looking even more attractive.

[JayCeeDee]

That’s interesting, Dave. My head is still back in the hardwired game. I didn’t realise that priority ( QoS ) had more influence than bandwidth.

Setting that up will be interesting, due to , as you show, assumed facts creating errors that knowledge of networking would avoid. Maybe that will be an interesting business model ( ie less physical/easier life ) for you as you head toward retirement !!??

[Wheels-Of-Fire]

The real operational difference between a skype call and a sip call is that we keep using phone numbers instead of ip addresses.

PABX manufacturers have been supporting SIP (session initialization protocol) trunks for years.

In in order to use sip trunks you must sign up to a sip trunk provider. The provider may or may not supply you with an internet connection ( you can use your own) but it must provide a sip server and a telephone number for all the trunks you rent (you can transfer your existing number if you like)

When you make a call a setup request using sip inside UDP packets is sent to the sip server. The sip request will contain a destination phone number. If the request is successful then a TCP connection will be established using RTP (real-time transmission protocol) to carry the actual audio. RTP its self does not garuntee QoS but it helps with reassembly of packets and gives a strong hint to QoS mechenisems.

The provider of your sip trunks will have a link into the PSTN using either traditional Q931 digital links or maybe even more sip trunks !

[Richard]

I have been retired for 17 years now, yet for years before I retired the end of the old POTS switching network was a hot topic. Dave is right, VOIP does not require bandwidth, all the gaps in activity plus the limited amount of actual content mean that the data demand is trivial, but consistency of delivery is everything. Already in the 1990s some traffic was bulk carried via data links not ‘conventional’ channel based facilities.

It is surprising that the same old issues are still yet to get a good customer end solution. The need for service protection during power cuts being one, the ‘other services’ run off POTS is another. I run my DECT phone system off a UPS and have toyed with UPS for the router and data switches, but mains voltage UPS for low voltage data switches feels like a logic failure. I saw that Ofcom were suggesting one-hour mains fail device protection should be mandated for network terminating equipment, I guess it is set that low for cost control reasons, but it sounds a trivial target.

I noticed that some respondents pressed for an end to numbering plans built up from local through national geographic numbering schemes in favour of using e.g. names as call partner ID. This was based on their Skype usage, I don’t see that playing easily in the real world as an addressing plan.

[Wheels-Of-Fire]

If BT and the others do decide to ditch the switched phone network then the terminating equipment for a SIP service could easily be a line powered smart socket. All the socket programming would be done by the provider at their end and all you would have to do is plug in your existing phone.

More sophisticated services could be provided to those who like to play with their network settings but it would be up to them to provide backup power ?

[Richard]

Oops, I should have said VOIP does not require much bandwidth not what I wrote.

The provision of the end drops to customers is a topic that I have not followed, intelligent cabinets that could build self healing network were at one time a much punted idea by such as Ericsson, though provision of power to cabinets was a subject for debate at the time. I am not sure that the internet service preventers would take too kindly to providing power to CPE such but if that is what Ofcom decide then maybe that is what will arrive.

The issue of divers alarm systems and different monitors appears to remain a to be decided issue.

[Bob Williams]

dwynnehugh wrote:

” …. that happening. 2015 is not that far away, BT a…..” Sorry to burst your bubble Bob but 2015 has been in North Wales – perhaps we’re not that far behind the times after all!!! LOL

Meant 2025 Dwynne, my fingers don’t always follow directions! Some very interesting information here from all you guys. I thought this thread would provoke a response and educate me a bit more! JCD, I am doing OK atm, after a long tussle between BT and my ISP Plusnet. BT crashed all phone and BB in the village, I posted some time ago about this. They put in a new ‘Superfast’ cabinet (hollow laugh) but did not research what fibre capacity they would need. Result: BT tells customers and other ISP’s here that we can all go to Superfast Heaven. Whole system crashed within days, some 90% of village without phones or BB, After a long battle, BT had Openreach build a cabinet 3x original size: the ‘join’ can still be seen. Now this is what Plusnet give me:

Which is not bad, I think you will agree.Just tested my phone: 16 Ping, 69.6 Down, 18.7 Up. After our holiday, I might look at my BB and WiFi again.

 

When the Thought Police arrive at your door, think -
I'm out.

[Wheels-Of-Fire]

Speaking of fibre capacity Bob, when I was back at college in 1991 I had to sit through and pass a tedious unit called Transmission principles.

We were taught that the original fibre optic cables were multi mode with multiple wave fronts and a definite maximum speed. The next generation were graded (refractive) index with a higher top speed. The current generation are really thin mono mode and their speed limitation is only dependent on how fast you can switch the signalling lazer on and off. There is a lot of the old stuff out there though.

[Bob Williams]

Thanks Graham, good info. More education!

When the Thought Police arrive at your door, think -
I'm out.

[Dave Rice]

Bob, I think your house infrastructure will be OK, unless you have any dead spots.

I use a range of different bits of kit to measure bandwidth, whatever is to hand basically.  Mobile phones are nearly always worse than the laptop – I think it’s down to smaller antenna – but iPads are just awful.

Unless you’re pushing lots of data around your house then really you only need it to be quicker than your ISP can provide as that’s the bottleneck.

[Bob Williams]

Thanks Dave. Just as I thought: the walls of our bungalow were Council-built in the early 1960’s. Externals are pretty solid walls, but internals are made of something approximating compacted brick dust. Fixing anything to an internal wall always requires expanding rawlplugs and paying close attention to the spirit level!

The Plusnet Hub One router is not as bad as some make out, certainly much better than the Sky one ever was. My phone pings when passing by the bungalow behind my own, coming home on the A157. There is good WiFi all over the house and outside, so when I get my new replacement shed later in the year. I may turn that into a Man Cave. With permission ??.

One question: can I fit a TP-Link SG-105 to a cat 5e in the lounge for 2 or 3 devices, and another here in the desktop room/spare bedroom? Both connected by a Cat 6 cable from the 5-port router.

Cheers, Bob.

When the Thought Police arrive at your door, think -
I'm out.

[Richard]

Graham, many, too many years ago PCM was the hottest thing that was coming in. The economic run lengths were said to be something like 28 miles, but from 14 upwards would be acceptable. What length were the first installed runs? Less than half a mile in the city of London. The plant might have been costly, but digging up the ducts to expand them would have been far more expensive, even if it had been allowed at the time.

I guess it is a similar with optical fibre plans at the moment, glass is fragile  and does not like to bent as one, once large, now bankrupt maker of hardware found out. The cabinet was nicely connected up and tested perfectly, the cabinet door was closed and every fibre connection was promptly ‘unmade’, it just would not bend enough to fit into the space.

Having a hierarchy of media is no doubt driven by market needs. Synchronising between systems was an issue, with different systems running to quite different standards and time clocks. So plesiochronous buffers were a hot topic, ownership of these devices sometimes came close to causing minor wars. In one meeting I offered to get the fire axe so that the warring tribes could take half each. They then decided to take the ownership matter off-line.

Perhaps I am glad that I am now a long time out of the business, though I can see similar potential for re-runs of old delays and disputes as the latest conflict spheres form. Perhaps that is still the sort of issue that bedevils BT and the others trying to roll things out.

I envy you Bob, my download speed cannot come close to your upload data rate though to be honest it serves our modest needs OK.

[Wheels-Of-Fire]

Richard, synchronisation is still a problem with TDM based systems.

The UK has a full Plesiochronous hierachy with BT maintaining an atomic master clock. When Mercury came along they setup their own clock but it was in sync with the BT clock because they both run on Universal Standard Time. All was right with the world.

Our PABX’s ran off an internal clock if they were only connected to analogue lines but once you connected a digital trunk they could be set to use that as the master clock instead. All was still right with the world.

When the market was opened up to other carriers we hit a problem. Sprint for instance maintained its own master clock that was synced to Universal time but it was in the USA. By the time their clock signal reached the UK it was out of sync with ours.

If one of our PABX’s were connected to UK and Sprint trunks it was impossible to send faxes over one or the other depending on which you set as master.

 

[Dave Rice]

Bob, you can connect switches anywhere you like as long as you stick to a spoke – hub  configuration i.e. you don’t put a loop in.

So a spoke could link to a new hub no problem, but that new hub mustn’t have a link into any other existing hub. Think branches on a tree.

[Bob Williams]

Thanks Dave, I understand that. Very good analogy.

When the Thought Police arrive at your door, think -
I'm out.

[Richard]

Dave, is that strictly true? I have a router let us call that K1, this is connected to several dumb switches, Dumb 1-X, at least one of which, SubDumb1 has a connection from another dumb switch Dumb1. This is partially due to legacy issues Dumb1-X are gigabyte switches while SubDumb1 is only 100Mb and partially due to ‘growth’ issues, the TV and its hardware do not need GB connections. Subdumb2 is a redeployed router serving a small community of low port speed devices. SubDumb3 is connected by a Tp-Link Ethernet over mains power system, but from the Dumb1 switch. It is too early in the morning to try drawing something out, though I really should, it is challenging to remember it all. I am off out shortly so it will have to wait for a future time slot.

The switches are daisy chained so all sit along a spoke or spokes as needed and have only one path back to the router, which is I think what you were suggesting as a rule for operation.

[Ed P]

VOIP was actually built-in to the original BT HomeHub in the very early noughties. It was damn good and enabled us to save a fortune in overseas calls, then some b-accountant at BT saw the impact on BT’s income and chopped it out of all the Homehub upgrades. In the original version it was simple to use and did not need a Voip/Voip connection for many destinations. Instead we could use Voip/POTS via a friendly router or something at the destination. (so long ago I cannot remember the details)

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