As described in my earlier post, copied from then knowledgbase:
Mobile Call Control
Mobile Call Control (MCC) is a mobility feature similar to but independent of one-X Mobile. MCC allows any mobile phone user to access IP Office features without using the one-X Mobile client application. It uses FNE 31 (Star Star Service) to provide dial tone to the mobile phone user. "Star Star Service" is implemented using the same underlying methods as the one-X mobile FNE service but has no relationship to it.
A Mobility Feature license is required for an MCC user. One instance of the Mobility license provides a user with all the mobility features including MCC, one-X Mobile and Mobile Twinning (unlicensed in R9+).
MCC users can gain access to the "Star Star Service" dial tone when they receive a twinned call. After receiving a twinned call, the mobile user can dial ** to place that call on hold and get dial tone from the IP Office. Once the mobile user receives IP Office dial tone, any subsequent dialing done is interpreted as if the user is logged into an analog extension on the IP Office.
To gain access to the "Star Star Service" dial tone, the mobile user can dial the FNE 31 DID/DDI that has been programmed in the IP Office. Similarly, once dial tone is heard, the user can dial numbers and short codes as if the user is logged into an analog extension on the IP Office.
The trunk requirements for the "Star Star Service" FNE are the same as for the one-X Mobile. That is, trunks that support clearing supervision are required. Supported trunk types are:
IP500 Universal PRI (Not supported on legacy PRI on a carrier card)
IP500 BRI
SIP (RFC2833)