Configurations
Voip / PSTN / Hybrid Systems configuration
	The MARS system is very versatile and can be configured for use with many different types of extenal lines and extensions. The first example illustrate a VoIP only configuration with one or more VoIP lines and 4 VoIP phones as extensions.  Good quality and inexpensive phone like the GrandStream BT-102 are now widely available. The second example is a PSTN only installation (No Internet / VoIP) using a FXO gateway to connect the PSTN lines to the MARS PBX. Extensions 200 - 202 are VoIP phone and the extension 203 is a WIFI phone like the Linksys WIP300. The third example is a hybrid system with one PSTN line and one or more VoIP lines. The extension 203 is a conventional phone connected to the FXS port of the FXO / FXS adaptor. This arrangement uses one PSTN line for the ADSL (Internet) / VoIP and as the conventional line of the system (PSTN)  using an ADSL line filter.
"Virtual" Office
This diagram shows how a "virtual" office can easily be created using the MARS system. The MARS system is installed at location A using a single PSTN line with ADSL Internet access. There is one phone at this location with extension 200. The 3 others extensions are in different locations and linked to the MARS system over their Internet connections. As in a standard installation, inbound calls can be directed to any extension, and an extension can call another one using it's 3 digits number.  The 3 remote extension will share the system PSTN and VoIP lines and the service offered by the system (i.e. automated attendant, voice mail, queues, etc ...).
Linking MARS Systems
One of the most interesting aspect of the MARS system is the fact that you can interconnect up to four systems together over a direct Internet link. This allows not only to place and receive free calls in between systems in different locations but even to use the external lines of a remote system to place a call.   An extension on a given system can directly dial another system extension using it's 3 digits extension number. Incoming calls can also as easily be transfered to an extension on another system.  Calls can even be placed using the external lines  of a remote system by simple prefixing the telephone number by star followed by the server number. For instance, dial "*2 418 555 1212 #" from an extension on server A to dial a number using an external line from server B.
MARS as a WI-FI phone to VoIP gateway
	Because of it's built-in full featured WI-FI access point, and PBX, the MARS system is ideal to implement a wireless VoIP gateway.  Using WI-FI SIP telephones like the WIP300 from Lynksys. The WI-FI phone will appear as normal extensions and will be able to place and receive calls  within the WI-FI range over the VoIP or PSTN lines of the system.