How to circumvent the restrictions of DS-Lite

Internet providers are increasingly moving towards only providing customers with pure IPv6 connections (DS Lite or CGN). However, the i-telex software is only IPv4-compatible. This applies not only to pure Internet communication, but also to the underlying database structures for TNS, etc. IPv6 capability for i-telex is currently not in sight.

With DS-Lite, all carrier internal traffice is done via IPv6; transition to IPv4 network is done at the carrier borders. That means that your router is not reachable from the IPv4 part of the internet, and also your piTelex device is not. To make piTelex reachable externally in this case, there are different approaches:

Centralex

This option enables users without a public IPv4 address to participate in the i-Telex network. If this option is activated, piTelex establishes a dedicated connection to a switching server equipped with an IPv4 address. Every incoming connection destined at the piTelex station is then routed via this server, which forwards it to the piTelex station. The switching server is also often called Centralex.

For details, see the Centralex documentation