How Will NBN Voice Services Work?
Subscribers have long assumed ubiquitous availability of reliable fixed line voice services. The NBN will replace the fixed line voice network, and hence must provide an alternative to it.
The NBN provides a “layer 2” service. This means that the NBN presents an Ethernet port (connection) to subscribers, another one to Service Providers (known as Access Seekers), then transfers Ethernet frames (packets) between these ports according to a previously agreed Quality of Service.
In other words, the NBN provides a pipe. Service Providers use it to offer products: Broadband Access, Pay TV etc.
However many subscribers will demand on-going access to a fixed line voice service, or a similar alternative. Supporting voice services is a key NBN objective, this report shows how it is done.
Background
From a subscriber perspective, fixed line voice services generally appear as one or more “RJ11” wall sockets. Handsets (cordless or fixed) plug into these sockets via the standard RJ11 plug, a fixed line voice service results.
In particular, the telephone socket provides electric power to operate the handset, transfers dial tones, ring signals, numbers for call setup and analog voice signals.
The NBN must replicate this socket, so that existing handsets can be plugged in and work as before.
Although the socket may be replicated, the remainder of the fixed line voice infrastructure will not be, as the NBN has replaced it. As outlined above, the NBN is a layer 2 service provider. Voice services provided over the NBN network will be based on Voice over IP (VOIP), similar to current subscriber voice services offered by companies such as Engin.
However voice services running on the NBN will be sold by third party Retail Service Providers, not by the NBN. This is in keeping with the NBN “wholesale” layer 2 service provider mandate.
Nonetheless the NBN must provide as standard the infrastructure needed to support VOIP services, as well as voice call data capacity.
This works as follows.