[Sussex] VoDSL - Waiting in the wings

Tue Sep 16 23:34:07 UTC 2003

On Tue, 16 Sep 2003, Angelo Servini wrote:

> Not a "Linuxy" subject, but I thought it would be of interest.

ooo, VoIP :D

> from: "Broadband Magazine May 2002"
>
> http://www.broadbandmag.co.uk/features/may_02/VoDSL.htm

Should prolly read that at some point...

> VoDSL is a technology that has the potential to dramatically shake-up the
> local access voice market. And this is the reason why its transition from
> laboratory to mass-market deployment will be made in the teeth of a spirited
> rear-guard defence by the incumbent operators of Europe

You may have heard of it as VoIP, or Voice Over IP. It's not a new
technology.

> While the current cloud of economic uncertainty hangs over global telecoms
> markets, talk of investment in new technologies sounds hollow - particularly
> since it was partly this, in the guise of 3G and backbone networks, that has
> brought the sector to its present sorry state. But the industry will not be
> in reverse forever and when it does find first gear it will have to look
> collectively at the range of new technologies that have been mothballed
> since the industry went into 'freefall'.
>
> And among the most seductive - and potentially significant - is
> voice-over-DSL (VoDSL) technology. VoDSL enables operators to offer
> broadband data access and multiple voice channels over the same single
> twisted pair access line.

I wonder if VoDSL is just a branding name, or if it is actually different
to VoIP. I'm guessing not. Will we start seeing terms such as VoLL (Voice
Over Leased Line) or Vo56k, VoS (Voice Over Sattelite), VoWiFi etc...?

> Three sets of equipment are required to implement VoDSL:
>
> * An integrated access device (IAD) at the customer premises
> * A DSLAM (DSL access multiplexer) at the carrier's local exchange
> * A voice gateway, which transfers the voice traffic from the DSL network to
> the public switched telephone network (PSTN).

OK. The IAD is a router with a phone stuck in the back. Not a difficult
piece of technology.
DSLAM - You have one of these if you have xDSL.
Voice Gateway... ah ha! That's interesting. A voice gateway is a box that
effectively has voice in one one side and a connection to the PSTN on the
other side. A bit like that one sitting in the corner of my room running
Linux. (http://www.asterisk.org/)

> This enables computers, telephones and fax machines all to be connected to
> the single line. 'The IAD takes the voice and data through the DSL line to
> the DSLAM,' says Mahendra Soneji, director of Product Marketing at Polycom,
> a US IAD manufacturer.
> 'The DSLAM can have thousands of lines coming in from various customers,'
> says Soneji. 'The device bifurcates (splits) the information and sends the
> voice traffic - which can be compressed - to a voice gateway connected to a
> class 5 switch and over to the PSTN, and sends the data to the Internet via
> an ISP.'

Right. That sounds like a clever way of saying 'It routes IP traffic'..
considering if it didn't, it'd be pretty useless.

> With VoDSL provision over ADSL, users can typically expect to operate
> between two and four telephone lines alongside a concurrent broadband data
> connection, says Allied Data's director of sales worldwide, Shane Rigby.
> Additionally, he says, the voice calls will be of toll quality.

Hmm, interesting. The beauty of VoIP is that you can select the CODEC that
is used. Each has it's advantages and disadvantages. You can have poor
(i.e. analogue phone) quality at a coupla kB/s, or decent (ISDN or above
quality) for 7/8 kB/s.
That is a typical salesman statistic. It is all dependant on how much the
ADSL link is utilised. If it's maxed out, there's no bandwidth avaliable,
therefore no VoIP traffic will be routed, or it'll be routed very slowly.
This is where QoS comes into play - you can guarantee bandwidth will be
avaliable for 'realtime' traffic such as Voice over IP.

> A threat
>
> However, while VoDSL looks good on paper, in the immediate future the
> technology's potential is likely to remain untapped in any large-scale
> capacity. The reason is simple: incumbent operators across Europe, which
> despite the EU's best regulatory efforts dominate DSL networks, are
> reluctant to deploy it. As they see it, VoDSL would eat into their existing
> local voice revenue streams. [An integrated voice and DSL service would be
> cheaper to provision and regulators would expect incumbents to pass on cost
> savings to their customers].

Lets take a real world example. I have a friend in the Netherlands, who I
speak to both on the phone and via IRC. Sometimes, he's not on IRC and I
need to speak to him... so I pick up the phone and dial. I have to pay BT
x amount per minute for this call, which costs them next to nothing. They
make a fortune on the call and I get to speak to my friend. This is good
for both parties... assuming my bank balance isn't a 'party'.
However, now I have all this (fairly) cheap technology, I pick up my VoIP
phone, call his VoIP phone and we talk, at a much higher quality than an
analogue phone conversation. For no money. (well, ADSL charges, but
basically no money as my ISP doesn't charge me for my DSL) Furthermore,
supposing I make another friend in NL. s/he doesn't have an IP phone, so
we're back to paying BT xp/min for the privilige of using their crappy
copper. But wait! I can call NL for free. My friend with the IP phone also
has a linux-powered PBX... plugged into his phone line... :) Now, I pick
up the IP phone in the UK, dial an access code (i.e. 7) then the NL number
I wish to call. The call flys across the internet, to the PBX in NL, then
out onto the phone networks over there. No longer do I pay BT for the
international call charges, but I pay whoever the NL PBX is connected to's
'local' or 'national' call rate. Nice and cheap :)

Anyway, that is why people don't want to implement VoIP... it will cut a
HUGE chunk out of traditional voice carrier's revenue.

> But if we fast-forward five years from now and imagine a 'telescape' where
> multiple CLECs operate throughout the region and incumbent dominance of the
> local loop is a thing of the past; we may well begin to see the emergence of
> the first flat-rate, bundled voice and data packages - where voice calls are
> effectively free. And once this is established, Europe really will be on its
> way to the 'networked e-conomy'.

One of the main things I love about VoIP is the fact I can pick up the
phone and call anyone, anywhere in the world. Supposing you're a large
company, with lots of offices all over the world. It'll cost you a fortune
to use the regular phone network to make calls between offices - but with
a simple PBX in each office, a dedicated DSL line, and a few linecards
(coupla hundred quid a pop for PRI/BRI (ISDN) or T1/E1 cards) you can call
anywhere in the world for the cost of a local call in that country
(assuming you have a presence).

> Smith continues: 'Once customers start using VoDSL, they won't need to buy
> private branch exchanges (PBXs) any more, so when they come to renew them,
> they can save on capital expenditure,' he says. 'It doesn't sound a lot,
> ?6,700 for a PBX, but if you're a local solicitor, that represents quite a
> lot of money.' In contrast, Smith believes that larger companies are less
> likely to want VoDSL because of their larger bandwidth requirements and
> their existing convergent voice and data solutions.

£7k isn't a lot of money for a solicitor, lol. They prolly make that in a
day ;)
Ripping out your existing infrastructure isn't a good thing, however if
you're starting from scratch, VoIP is a good way to go. It grows as your
business grows. However, I don't think PBX's will become obsolete any time
soon. They have too many features (call parking, voicemail, hold music,
etc). No doubt the provider of these 'IAD's' will charge for all these
services, and you'll not be able to control all the 'niggly little bits'
like what music is playing when a customer is on hold.

> Furthermore, says Scott Rex, principal partner and senior research analyst
> at Research First, 'Internet-centric small businesses recognise the powerful
> competitive advantage of VoDSL. This can translate to a huge boon for
> service providers, provided they focus on critical deployment factors that
> lead to cost-effective bundled services.'

I noticed that too! I'm not even a small business... I just thought about
it logically.

> There is undoubtedly a lucrative market for VoDSL across Europe;
> unfortunately, however, by definition it must piggyback developments in the
> DSL market which is yet to achieved mass-market status and probably will not
> for some time. Additionally, VoDSL, whether asymmetric or symmetric, is not
> for everyone - it is unlikely that large corporates would ever see the
> benefit. But this still leave millions of small and medium-sized businesses
> that would reap significant commercial benefits from a VoDSL solution. Alas,
> until incumbents are forced to relinquish their strangle hold over local
> access, these benefits will have to go begging.

hmm, "unlikely that large corporates would ever see the benefit"... does
this mean that the company that wrote this article doesn't have the
infrastructure to cope with lots of calls at once? Interesting...

Well, to sum up... that sounds like one big advertising article for 'the
next big thing'. Please excuse this email (if you've got this far down)...
i'm just having a general rant/think aloud. And I think VoIP rocks :)

Jon

P.S... in case anyone's interested, i have the following setup at home:

1 Snom IP Phone (www.snom.de)
1 Asterisk PBX (www.asterisk.org)
1 FXO and 1 FXS card from www.telappliant.com

and an account or two from http://fwd.pulver.com/

This means that I can:

* Dial from any landline into my PBX over my analogue line, and make VoIP
calls over the internet.
* Dial via VoIP from anywhere in the world to my PBX, then out via my
analogue line.
* Dial in via VoIP or POTS to have an automated service status of my
network read back to me

*shrugs*.... I wanted the features, not the £xxxK price tag that went with
a decent PBX, so I implemented it myself.
-- 
Jon Fautley           >o)     .^.     (o<   jon at geekpeople.net
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           kill -9 'em all, and let root sort them out