Albatross TwinSIM routing application service enables a mobile operator or MVNO to offer customers two SIM cards with only one main telephone number. 

The SIM cards can be used in different mobile phones, for example:

  • Car and residential phone.
  • Business and leisure phone.


Calls to and from the TwinSIM customer are handled as if the customer has one mobile phone with a single mobile number. There is a unique telephone number (MSISDN) associated with each SIM card, and one acts as the Master whilst the other the Slave. The Master number is used to reach the TwinSIM customer, but a call to the TwinSIM Master number alerts both Master/Slave handsets.


If one of the phones is busy, calls are connected to a Voicemail solution. Calls from both phones are always presented with the same CLI or A-number.


The service is based on our iNode system with a fully redundant solution. IN requests are sent by the operator’s switch (Mobile Switching Centre, MSC or Service Switching Point, SSP) to our iNode (Service Control Point, SCP). CAMEL Phase 4 protocol is used, but other protocols such as INAP CS2 can be used in the same node.