The quality of your professional phone line is important in the every day functions of your company. As with all IT services, there are several different solutions available to best meet your needs.


SIP Trunking is a form of VoIP that transports voice communication using the IP protocole. The advantages of SIP Trunking include the capability to connect your phone directly to your IP-PBX without the need for a gateway, and the capacity for a large volume of communication channels without exorbitant costs.

The quality of SIP Trunking depends heavily on a stable Internet connection. If you rely on an ADSL or any other connection that is not dedicated and guaranteed or an unstable connection but would still like to explore the option of SIP Trunking, please consult our Internet services.

Centrex is a second form of VoIP where a PBX is hosted in the Alionis datacenter and either shared among several clients or shared among several branches of the same company. Centrex is the most economic solution available and also allows for several branches, or telecommuting employees, to have the same standard phone number.

VGA is an alternative phone service to France Télécom. For clients wishing to change Operators but already own a PABX, VGA allows you to keep your current phone infrastructure in place.

There are two different types of VGA:

  • a classic analog line
  • grouped or isolated BRI (Basic Rate Interface) line