Jump to content

Recommended Posts

Posted
4 hours ago, Sensei said:

UDP packets don't demand confirmation of delivery from recipient. So sender (application) does not know whether data arrived to recipient at all.

TCP packets require confirmation from recipient. If packet is lost, there is demanded resending of data. It slows down transmission a bit.

 

VOIP usually uses UDP. Human can hear if there is a transmission error, the loss of some packets, as a crackling sound. And then you can tell other human to repeat.

 

All true.  The point I was trying to make though is that any IP (like UDP and TCP) packet can be delayed (or even lost/dropped) whereas phone communication uses protocols (and transmission infrastructure) that are timely so that conversations aren't interrupted most of the time.  I think in the future as communication becomes cheaper, has abundant bandwidth and is faster, none of this will matter and internet calls will be as smooth as phone calls.  VOIP still needs a gateway to POTS/wireless phones though, and that will matter less and less also as more people move to VOIP type of communication.

 

  • Replies 59
  • Created
  • Last Reply

Top Posters In This Topic

Posted
Quote

Independent carriers such as Level 3 Communications and XO Communications are already all IP, while a significant number of smaller and rural carriers either have or are in the process of switching to nearly all-IP networks because running VoIP is cheaper, more power efficient compared with the PSTN, and more flexible to configure and add new services.
Two issues are holding up a more rapid phase-out of the PSTN: the large base of installed PSTN hardware at the core of the network and copper at the last mile. Tens of thousands of PSTN switches currently in operation can’t be replaced overnight because of the considerable time and expense involved. It will take years, if not a decade or more, for Tier 1 phone companies to gradually phase out all the existing PSTN equipment, replacing it with simplified IP-based hardware. Given that the average age of a legacy PSTN switch is more than 25 years and replacement parts are becoming more scarce every year, carriers have good incentive to put in new equipment as they find the money. Copper wiring may prove to be more challenging. Verizon says that it is not economical to maintain the existing copper “last mile” facilities that deliver dial tone to homes and is urging its customers to migrate to its FiOS fiber offering. For customers who don’t have access to fiber, Verizon has tried to introduce a wireless replacement strategy, but customers have found that wireless doesn’t support services such as faxing, credit card readers, and existing home alarm systems. 

     https://it.toolbox.com/blogs/voipdesk/when-does-the-pstn-end-and-voip-take-over-022615

Posted
32 minutes ago, Moreno said:

I didn't read the article, but POTS can run for 2 weeks off their batteries (need to switch to an old-school line-powered phone) whereas VOIP?  That's why I still have a land line, that plus ADSL(internet) comes in on the phone line as well.  I think wireless phone towers last a few hours after power goes out (last I heard).  It sure will be interesting when satellite phones become cheap - no power outage issues there except your own phone power.

 

Posted (edited)
39 minutes ago, Frank said:

It sure will be interesting when satellite phones become cheap - no power outage issues there except your own phone power.

Satellite transmission has extremely large delay (in comparison to optic fiber transmission e.g. transoceanic cable)

Calculate distance from the ground to satellite (e.g. geostationary orbit), then to eventually other satellites, then from satellite to the ground, divide by speed of light.. It's minimal delay you can have. Double that if you're interested in reply delay.

GEO are at equator ~ 36,000 km away.

https://en.wikipedia.org/wiki/Geostationary_orbit

 

Some use LEO (and require plentiful of satellites), some other use GEO orbits (less satellites needed for worldwide transmission).

https://en.wikipedia.org/wiki/Satellite_phone

 

Edited by Sensei
Posted

I was thinking about the LEO constellation since rocket launch costs are 10x cheaper now and still dropping.  Satellites are getting smaller and faster too.  Haven't looked into it in depth though, just peripheral info from launch providers (Musk and Beck).

 

(600 kilometers) / the speed of light = 2.00138457 milliseconds  (so maybe 5 ms delay?)

Posted
On 25/01/2018 at 2:35 PM, Moreno said:

So, you propose to give up cables and switch to wireless completely? Not that I would be against of it but for now people don't seem ready to do that.

I have just cancelled my landline.

On 25/01/2018 at 1:21 PM, Moreno said:

If you have mobile Internet you can make calls for free using Whattsap to any location in the World. But you cannot make calls using Whattsap to a landline.

I don't know anything about WhatsApp but with Skype you can pay to make calls to landlines. Which makes sense: someone has to pay for the phone call. So, technically, WhatsApp could allow people to make (charged) calls to landlines but presumably they don't see it as relevant to their business model.

Posted
On 1/25/2018 at 8:35 AM, Moreno said:

So, you propose to give up cables and switch to wireless completely? Not that I would be against of it but for now people don't seem ready to do that.

If you never had a cable, there's nothing to give up. You still seem to be centered on industrialized nations that have cable infrastructure, and that is by no means the whole picture. And even for industrialized nations, the landscape is changing. As I posted earlier, half of the US has no landline anymore. 

If you have a cell phone, and don't make international calls, of what use is Skype, et al.? What fraction of the population makes international calls?

 

Posted

Some folks do keep landlines due to poor cell coverage in their location. This is most common in rural areas where the mobile phone has poor signal. A landline is the only way they can get a consistently successful call and in and out, but it is certainly the exception, not the rule.

Skype is also used by far more than just mobile phones via the app. It's also used across huge numbers of very large corporations as the primary channel for 1:1 calling, group conference calls, and video teleconferencing. 

Landline phones may never go away 100%, but then again neither did horses and buggies. It's just such a marginal use case that we can generally ignore it and focus on the coming trend of VoIP and internet only communications.

Posted (edited)
16 minutes ago, iNow said:

Some folks do keep landlines due to poor cell coverage in their location. This is most common in rural areas where the mobile phone has poor signal. A landline is the only way they can get a consistently successful call and in and out, but it is certainly the exception, not the rule.

It may not be the rule but it's certainly a reasonably broad exception.  I live in a village in the UK that is only 5 miles from the centre of a city, but I can't reliable hold a conversation on my mobile phone in my own house.  It's still a pretty common issue in the UK (and I've even had trouble with signal in central London).  Netflix for example would almost definitely be out of the question.  At least in the UK, mobile phone tech is not good enough for us all to ditch our landlines just yet.

Edited by Juno
Posted
1 minute ago, iNow said:

I know the feeling, which is why I try to supplement with VoIP

Yeah, it looks like where I am is just a black hole as far as mobile coverage is concerned, so I won't be getting rid of my landline any time soon.  My point was that this isn't really an exception in a country like the UK, but actually pretty common for anyone who doesn't actually live in a city (and sometimes for those who do).  

I suppose the other point is that we don't have as wide-ranging a cable network like the US does, so for a lot of people if they want TV beyond what's available through their aerial then they need to keep a landline to run the fibre service down.

Posted
18 minutes ago, Juno said:

Yeah, it looks like where I am is just a black hole as far as mobile coverage is concerned, so I won't be getting rid of my landline any time soon.  My point was that this isn't really an exception in a country like the UK, but actually pretty common for anyone who doesn't actually live in a city (and sometimes for those who do).  

I suppose the other point is that we don't have as wide-ranging a cable network like the US does, so for a lot of people if they want TV beyond what's available through their aerial then they need to keep a landline to run the fibre service down.

Who knew???

Posted
58 minutes ago, Juno said:

we don't have as wide-ranging a cable network like the US does

Keep in mind, it's probably not as good as you assume. Much like you, it's only once you get to more densely populated urban areas that coverage is really all that great. A nice article for context, along with a key snippet below:

http://www.speedtest.net/reports/united-states/

MSA-RSA@2x.jpg

Quote

Acceptable Speed Ratio (74.9%) with that in RSAs (69.6%). That means on average all those places in blue on the map above are almost 7% less likely to experience an internet connection that’s acceptably fast. Considering the Acceptable Speed Ratio for all MSAs taken together is 76.2%, there’s a strict divide in the consistency customers in more populated areas can expect from their internet experience versus what those in rural areas can.

 

Posted
6 minutes ago, iNow said:

Keep in mind, it's probably not as good as you assume. Much like you, it's only once you get to more densely populated urban areas that coverage is really all that great. A nice article for context, along with a key snippet below:

http://www.speedtest.net/reports/united-states/

A fair point on the mobile coverage aspect - as an example I had a look at Madison, WI, as a reasonably similar size city as Derby in the UK - you don't have to go much more than 5 miles from the centre to find black spots that look pretty similar to where I live.

On the cable coverage though, there's quite a difference.  According to this speech from the UK comms regulator from last year, 80% of UK households are still reliant on copper networks for their broadband, whereas in the US that's more like a third of households.  I can see why, on that basis, more of the US population would be willing to give up the copper-based landline.

Posted
1 hour ago, Juno said:

A fair point on the mobile coverage aspect - as an example I had a look at Madison, WI, as a reasonably similar size city as Derby in the UK - you don't have to go much more than 5 miles from the centre to find black spots that look pretty similar to where I live.

On the cable coverage though, there's quite a difference.  According to this speech from the UK comms regulator from last year, 80% of UK households are still reliant on copper networks for their broadband, whereas in the US that's more like a third of households.  I can see why, on that basis, more of the US population would be willing to give up the copper-based landline.

Is the UK business model for cable the same as the US? Broadcast TV is certainly different.

Posted
50 minutes ago, swansont said:

Is the UK business model for cable the same as the US? Broadcast TV is certainly different.

Yes, in the sense that we aren’t as reliant on it for TV - satellite is at least as common and I think has been around for longer.  I don’t know about their respective use for telephony though as I don’t think I’ve ever lived anywhere with cable! 

Posted (edited)
On ‎1‎/‎25‎/‎2018 at 8:17 AM, swansont said:

But if neither person has a landline, what would be the point?  In the US, half of the country has no landline anymore.

I think it is an interesting question whether wireless will completely replace cables someday.     I afraid that in order for this to happen a principally new type of technology have to be developed, based on principally different physical principles. Desirably, it suppose to be completely invulnerable to interference and make cell towers obsolete. Maybe something based on quantum mechanics? However, I afraid that such type of an "ideal" communication technology may create a huge social dangers which include at least:

1) Communications of wrongdoers which cannot be intercepted.

2) Remotely controlled bombs and suicide drones which cannot be jammed.

3) Electronic bags which cannot be jammed or detected.

In one word I'm not sure if humanity is ready for that type of technology yet.

Edited by Moreno
Posted
7 minutes ago, Moreno said:

I think it is an interesting question whether wireless will completely replace cables someday.  

Not completely but mostly. And soon. 

8 minutes ago, Moreno said:

1) Communications of wrongdoers which cannot be intercepted.

That is already possible (and easy).

Posted
22 minutes ago, Moreno said:

How exactly? 

I have never used it, but I gather WhatsApp is encrypted end-to-end which makes it impossible to intercept. There are several other communication apps that are similar. 

And if you are concerned about the authorities knowing that you have communicated with someone, even if they can’t tell what was said, then you can use something like Tor to anonymise.

Posted

WhatsApp is encrypted, but not impossible to intercept. Just not as easy. Signal is another similar app. 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.