Private-Branch Exchange that Provides Incoming Calling Extended to an Off-Premises Terminal in the Presence of a Third-Party Application

A method comprising:

• receiving, at a private branch exchange, at least one message from an application server, wherein said at least one message conveys a directive to establish a resultant call that includes a telephone number C and that is related to a first precursor call from a telephone number T;
• originating a second precursor call at said private branch exchange from a port P that is capable of emulating a telephone extension, wherein said second precursor call is directed to a telephone number D;
• and
• extending said second precursor call to said telephone number C;
• wherein said telephone number C is associated with said telephone number D in a data structure.

A method comprising:

• receiving a first precursor call from a telephone number T;
• establishing a second precursor call from a port P to a telephone number D and a telephone number C, wherein said port P is capable of emulating a telephone extension;
• establishing a third precursor call from said telephone number D;
• and
• combining said first precursor call, said second precursor call, and said third precursor call to generate a resultant call from said telephone number T to said telephone number C.

A method comprising:

• receiving a notification of a first precursor call from a telephone number T;
• determining that a port P is available for use, wherein said port P is capable of emulating a telephone extension;
• directing (i) a second precursor call to be placed from said port P to a telephone number D, and (ii) said second precursor call to be placed on hold at said port P;
• and
• directing (iii) a third precursor call to be placed from said telephone number D to said port P, and (iv) said first precursor call, said second precursor call, and said third precursor call to be combined to generate a resultant call from said telephone number T to said telephone number C.