CLIP (Calling Line Identification Presentation) provides the called party with the identity of the calling party. The identity consists of name and telephone number of the calling party. The Telephony Control Server is able to send identity information for the CLIP feature to a SP (Service Provider).
Identity information to be included in P-Asserted-Identity
header fields is inserted by the SSNE (SIP Signaling Network Element) that is responsible for the calling party. Therefore, the SSNE should authenticate the calling party in order make sure that the correct identity information is included.
The Telephony Control Server is able to send identity information for the CLIP feature to a Service Provider.
The Telephony Control Server is able to process received identity information for the CLIP feature from a Service Provider.
Functional Sequence - Sending requests and responses to SP
- P-Asserted-Identity header field
If the SP is considered part of the Enterprise “Trust Domain”, Lotus Sametime Unified Telephony will include the P-Asserted-Identity header field in SIP INVITE requests. Currently Lotus Sametime Unified Telephony does not support sending a private identity in the P-Asserted-Identity header field, this header field will contain the same public identity as the From header field . If the calling party is a member of a user group with a private numbering plan then the callers private numbering identity will not be sent in the P-Asserted-Identity to the SP.
- From Header field
The Telephony Control Server that is responsible for the calling party may remove the original identity information from the received From header field from the client and insert appropriate public identity information from the Lotus Sametime Unified Telephony database. Usually, this header field contains the desired public PSTN identity of the subscriber.
Functional Sequence - Receiving requests and responses from SP
The Enterprise system SHOULD be able to process a P-Asserted-Identity
header field in received INVITE requests from the Service Provider (for example, for display update and call logging purposes). If no P-Asserted-Identity
header field is present, identity information from the From header field may be used for these purposes.
Parent topic: SIP Trunking overview