[LINK] Naked ADSL and dumping the voiceline

Craig Sanders cas at taz.net.au
Tue Nov 2 09:35:01 AEDT 2010

On Mon, Nov 01, 2010 at 07:24:59PM +1000, Rick Welykochy wrote:
> Linkers,
> Perhaps this has been discussed before. I'm considering dumping the
> voice line, keeping the land line and adding VoiP to the mix.
> A few questions arise.
> * what device can I then connect to the naked line to give my current
>    (simple residential) telephone equipment full POTS connectivity?

nothing.  it doesn't work that way.  it's not POTS any more.

if you meant "how can i use my existing analog phones on my now
completely digital VOIP system?" then you need an ATA. they usually come
with one or more FXS ports (for plugging phones into), an ethernet port,
and optionally an FXO port (for plugging into a POTS wall socket). some
ADSL modems have ATAs built in.

the ATA is then configured to connect to your VOIP provider's server
(or your own SIP server if you are running asterisk or freeswitch or
similar).  incoming VOIP calls are routed to the old analog phones,
outbound calls are routed via the VOIP service.

ATAs with an FXO port are more expensive but are usually configured
to fall back to the POTS line for outgoing calls if the VOIP service
is down or unreachable. they also handle incoming POTS calls, either
by making the attached phones ring or (if you are running a local SIP
server) can forward the incoming call to your SIP server (and all
the features of that, including voicemail).  You can also override
the default outgoing call routing with a dialing prefix to force an
outbound call to go via POTS (and you can generally set up rules so
that, for example, 000 calls always go via POTS). the dialing prefix is
also useful if you have multiple VOIP providers, you can select which
provider to use for any outgoing call.

I had a setup like this for a while. when i switched from ADSL1 to naked
ADSL2 (iinet w/ iitalk VOIP service), i left the existing ADSL1 line
in place until the new ADSL2 service was running on a second line that
used to be a modem line. i then cancelled the old ADSL1 service, leaving
me with just a POTS line. it worked, but i resented paying $33/month for
the line just to keep the phone number.  I eventually ported the number
to faktortel - it now costs me $3/month.

I would have ported it to iinet but they don't offer that service(*).
the faktortel service is great but if/when iinet ever offer the service,
I will port it to them because a) I'd rather have just one bill, b)
iinet VOIP calls are exempt from the bandwidth quota, and c) iinet's
router configuration prioritises VOIP packets within their network.

BTW, if you are running asterisk or freeswitch and have an ATA with an
FXO port, they can also be configured to route (some or all) outgoing
calls to POTS via the ATA. as long as it's a real ATA. unfortunately
most (all?) modems with a built-in ATA either don't have an FXO port at
all or have only a minimally-functional (i.e. "fake" or "broken") FXO
port so can't be used like this.

(*) actually, they do...but only when you're first converting to naked
adsl2. they don't offer a porting service for additional numbers. so i
could have done it when i first switched to ADSL2 but i wanted to avoid
any downtime by running the old ADSL1 service in parallel until the
new ADSL2 service was ready. so now i have two phone numbers - one for
the VOIP service, and one kept from my old analog line and now ported
to faktortel. the former belongs to iinet and will stay with them if
i ever switch ISPs. the latter is mine and can be ported to any other
service provider (in theory. in practice, porting numbers is an ugly
mess requiring specific agreements between each individual SP and often
the easiest or ONLY way of porting it to another SP is to first port it
to telstra and then to the new SP...incurring costs and delays at each
port.  IMO this sucks and is something that should be fixed by the ACCC
and the TIO).

> * there obviously must be some POTS gateway/interface in the mix?
> * does the switch to naked ADSL affect my internet data connection,
>    modem or PC in any way?
> * do I pay anything for the naked line?

line rental is included in the price.  that's why it's called "naked".
if you compare an ISP's naked vs non-naked plans, there's usually little
or no difference in price so you effectively end up saving the $30+/month
that line rental would have cost you.

> * who maintains the naked line?

the ISP pays wholesale rates for the naked DSL line.  Whoever they buy
it from (e.g. telstra, optus) maintains the line. if there's a fault,
you contact your ISP and they get the wholesaler to fix it.

> * and the big question: would my only ongoing cost for VoiP then
>    be the bandwidth I use over the ADSL?
> i.e. this is a cost reduction exercise. Quite applicable to a move
> to FTTH if that ever happens where I live :)

depends on the ISP and/or VOIP provider.   some ISPs do VOIP, some don't.
some offer good deals, some don't.  You can also use a third-party
VOIP provider.

most (all?) ISPs that offer VOIP exempt VOIP data from the quota (only
to/from their SIP server of course, otherwise it would be possible
to tunnel data anywhere on the SIP ports, bypassing quota). so VOIP
calls don't use your quota, and aren't affected by shaping if you are

e.g. the Naked DSL service i have includes iinet's iitalk VOIP service.
this includes unlimited free calls to any land line in australia (calls
to mobiles and intl destinations costs more. most intl calls are cheap).
i never make intl calls, and use my mobile to call other mobiles
(included in my 3 Cap), so switching to VOIP saved me the line rental
AND all my call costs. given that i started off with two lines, i'm
saving about $100/month (two line rentals @ $33 each, plus calls).

whirlpool/broadbandchoice is a good site for comparing service offerings
and prices from ISPs. http://bc.whirlpool.net.au/bc/?action=search


ps: when the NBN is available in my area, i'll be switching to it
immediately. unfortunately i missed out by one suburb on one of the
planned trial areas (Brunswick - I'm in the next suburb over, Coburg).

craig sanders <cas at taz.net.au>

More information about the Link mailing list