The 3300 ICP supports MSDN/DPNSS features for PSTN calls that are received from a Siemens iSDX PBX. However, after the iSDX PBX delivers a PSTN call to the 3300 ICP, it activates a call completion timer. If this timer expires before the call is answered at the 3300 ICP, the iSDX PBX clears the call and redirects it to a local extension, typically an operator on the iSDX. To prevent this timer from redirecting calls that use MSDN/DPNSS features, such as call forwarding and system rerouting, you must configure the 3300 ICP to interwork with the Siemens iSDX.
A 3300 ICP can be the destination node of the PSTN calls or it can act as a gateway node to other 3300 ICP destination nodes in a network or cluster. If the gateway node is configured to interwork with the iSDX PBX, the other 3300 ICP nodes in the network or cluster will interwork with the iSDX PBX as well.
The 3300 ICP systems (gateway and destination nodes) must have Release 7.1 software or higher.
The iSDX PBX must deliver the PSTN calls to the 3300 ICP system (gateway or destination node) over TDM MSDN/DPNSS trunks.
iSDX DPNSS Interworking is supported for PSTN calls that are sent from the 3300 ICP gateway node over MSDN/DPNSS trunks, IP trunks, or XNET trunks to other 3300 ICP destination nodes in a network or cluster.
iSDX MSDN/DPNSS Interworking is not supported for PSTN calls that are sent over ISDN trunks, QSIG trunks, SIP trunks, or other common-channel signalling PSTN trunks.
To configure the 3300 ICP to interwork with a Siemens iSDX PBX:
On the 3300 ICP gateway or destination node, access the Digital Link Descriptors form for the TDM MSDN/DPNSS link.
Set the Vendor Inter-working Type field to "Siemens iSDX".
