In message , at 19:43:45 on
Tue, 12 Jun 2012, Jarle H Knudsen remarked:
Dedicated or prioritized (QoS) bandwidth for VoIP over DSL is no problem.
My DSL router is configured with a dedicated port for the VoIP adapter to
achieve this, together with some configuration on the DSLAM side.

QoS won't help you if there is congestion at the exchange or anywhere along
the line.

While this is true, if you get a VoIP number from your internet provider,
the calls will not be routed over the regular Inernet, so this will not be
a problem.

Which doesn't help if the congestion is between your exchange and your
Internet provider (on the BT wholesale backhaul, normally). Which is
where the congestion experienced by most domestic users in the UK
occurs, unfortunately.

The point beeing that it's perfectly possible to provide the
same quality as POTS over IP.

It is, but only at some expense.
--
Roland Perry