When a call originates from the 3300 ICP to the SIP service provider, it terminates on a SIP route. This SIP route is directed to the SIP Peer and the digits dialed are presented to the service provider.
When a call originates from the SIP service provider to the 3300 ICP, it is treated as an external PSTN-type call. The calling line category of the incoming call is set to CLC_ISDN. This allows for external treatment of the call for features such as call forwarding, call rerouting, camp-on, recall, and so forth.
From Service Provider - the calling number and name are based on what is available in the SIP header: first from P-Asserted-Identity, second from P-Preferred Identity, and third from the From header line. In some cases, this is not the information of the calling party, but the Parent number from the remote PBX/Softswitch placing the call. The P-Preferred Identity is only available in a back-to-back connection with another SIP 3300 ICP.
To Service Provider - The calling party information may be configured on a per peer basis. By default, the caller's name and number are delivered but can be suppressed using the SIP Peer Profile form. Prior to programming calling party information, configure CPN Substitution. First, program a DID range with a corresponding CPN substitution number on the DID Ranges for CPN Substitution form. Then, select the index number for the DID range on the SIP Peer Profile form.
Privacy on Outgoing Calls - the existing privacy mechanisms for the 3300 ICP can be used: feature access code for Name Suppression on Outgoing Trunk Call, and the Telephone Directory form using the Private field. The SIP Peer Profile form has an option for Calling Line ID Restriction. This option replaces the calling party name and number with anonymous for display. As well, a parent account may be in used based on the SIP Peer Profile configuration. If the parent account is used, it prevents the calling name and number from being displayed.
Privacy on Incoming Calls - incoming calls can contain a privacy header that prevents the caller name and number from being presented to untrusted networks or devices.
When a 3300 ICP user places a SIP Trunk on hold, the 3300 ICP provides Music on Hold, if programmed. The feature behaves similarly to PRI calls.
Call Transfer is allowed on SIP Trunks.
Call Diversion is not available for the SIP service provider. If the service provider sends a redirect request to the 3300 ICP, the call is cleared and the user receives re-order tone.
Calls on SIP Trunks are re-directed when the Call Forwarding feature is enabled on the 3300 ICP destination. The feature behaves similarly to PRI calls.
The SIP Service Provider may use a TEL URI calling scheme to the 3300 ICP. The SIP Peer Profile for Incoming DID form contains the mapping of the dialed digits to the SIP Peer. This mapping allows the correct policy to be applied to the incoming call. Different policies can be assigned based on the digits dialed from the Service Provider.
The SIP Service Provider supports Direct Inward Dialing (DID) to the 3300 ICP. Use the SIP Peer Profile for Incoming DID form to configure DID dialing. The incoming digits are limited to seven digits or less when translated by call control, and can terminate at stations, hunt groups, ACD paths, and speedcall. This feature operates the same as DID calling on PRI trunks. Trunk service options to insert or absorb digits work the same as they do on other trunk types.