This capability covers auto callback within a private corporate network only, for example, through QSIG. Communication Manager Release 4.0 or later provides an administrable option on the Trunk Group screen for users to specify the method of signaling connection the system uses while waiting for a busy station to become idle.

Using the TSC Method for Auto Callback field on the QSIG Trunk Group Options page of the Trunk Group screen, customers can administer whether or not to retain the Temporary Signaling Connection (TSC) when QSIG Call Completion (QSIG-CC) is activated with other Communication Manager servers, or with non-Communication Manager servers (like the I55 or Siemens Hicom). The default value for the TSC Method for Auto Callback is drop-if-possible. The other option is to set the value to always-retain.

Older QSIG-CC standards require Path Reservation, which is not supported by Communication Manager. QSIG-CC can fail if the QSIG TSC is dropped when connected to a server that does not support the latest version of the QSIG-CC standards. In order for Communication Manager to work with servers based on old QSIG-CC standards, this retaining option is needed.

Currently, the preferred QSIG-CC signaling connection method used by Communication Manager is the signaling connection release. In other words, Communication Manager populates the element retain-sig-connection in CCBS/CCNR invoke APDUs with the hard-coded value FALSE. With Communication Manager 4.0 or later, the new administration option on the Trunk Group screen controls:

• the element retain-sig-connection in CCBS/CCNR invoke APDUs, when Communication Manager is the originating PINX

• the signaling connection method for the QSIG-TSC when Communication Manager is the terminating or the outgoing gateway PINX

For more information, see Avaya Aura® Communication Manager Screen Reference.