[ivanhbk]

Here's the thing. I want to setup a GSM to VOIP system wherein several of my office staff can dial just one/same mobile number (let's say 99xx is the sim number) simultaneously and still be able to make the VOIP call.

If I'm not mistaken, a sim card can only accept one call at a time so how can these several others make the VOIP call when the line is occupied?

I have attached a simple diagram to make my meaning more clear. Please let me know of any suggestions wherein I can cheaply accomplish his setup. Thanks in advance for any suggestion(s)

[rizsher]

I doubt very much if a single GSM sim will allow multiple separate calls. The solution I can think of is to use multiple GSM Boxes (e.g. the one supplied by SIPCPE), connected to an Asterisk server which has a multi-port FXO card. You could get each employee to call the individual GSM numbers, or activate "On-Busy" forwarding on the SIMs, cascaded down all the numbers.. so... an employee calls Sim 1, if its busy, the call will get forwarded to Sim 2, on busy, that'll get forwarded to Sim 3 and so on.

I also don't think this'll be a very cheap setup to implement.

[edongp]

Originally Posted by ivanhbk

Here's the thing. I want to setup a GSM to VOIP system wherein several of my office staff can dial just one/same mobile number (let's say 99xx is the sim number) simultaneously and still be able to make the VOIP call.

If I'm not mistaken, a sim card can only accept one call at a time so how can these several others make the VOIP call when the line is occupied?

I have attached a simple diagram to make my meaning more clear. Please let me know of any suggestions wherein I can cheaply accomplish his setup. Thanks in advance for any suggestion(s)

A cheaper and easier way to make multiple calls using one VoIP account is to eliminate the GSM. Get a Vonage or Broadvoice account (VoIP services with the Call Transfer feature) and install a single line switch such as the DialMate CM1003 (see Dialmate - call back, dial back, call diverter, call bridge, call forward, best follow me, auto-attendant and unified messaging). From your cell phone call the VoIP line and make a call back (for free incoming cell phones such as Sprint/Nextel) or bridge call (for free and unlimited airtime to favorite numbers such as T-Mobile) using the call transfer feature of the VoIP line. Your call will be directly connected to the destination number as soon as the VoIP line hangs up which becomes ready for the next caller. Multiple users can then make calls almost simultaneously using only one VoIP account.
If you have employees anywhere in the world with VoIP lines(preferably free byods from VoiceStick.com - The Internet Phone for cheap local and long distance calling) having USA/Canadian numbers, they can use the call back feature of the CM1003 to make free calls using the Call Return (call back number programmed as *69) feature of the Broadvoice or Vonage account.