The present document specifies the stage three (protocol description) of the Enhanced Calling Name (eCNAM) supplementary service based on stage one description in TS 22.173. It provides the protocol details in the IP Multimedia (IM) Core Network (CN) subsystem (see TS 24.229) based on the Session Initiation Protocol (SIP) (see RFC 3261) where the eCNAM data is retrieved by the terminating network from trusted data sources.
The following documents contain provisions which, through reference in this text, constitute provisions of the present document.
References are either specific (identified by date of publication, edition number, version number, etc.) or non-specific.
For a specific reference, subsequent revisions do not apply.
For a non-specific reference, the latest version applies. In the case of a reference to a 3GPP document (including a GSM document), a non-specific reference implicitly refers to the latest version of that document in the same Release as the present document.
The eCNAM service provides the terminating user with the name associated with the originating user and optionally delivers metadata about that originating user. While eCNAM is a terminating service, the eCNAM operations rely on information received from the originating network, such as the originating user's E.164 telephone number (TN) to retrieve eCNAM data from trusted data sources (via methods outside the scope of this specification).
The eCNAM service provides the terminating user with a name that identifies the originating user, and metadata about that originating user (e.g., address, language).
To retrieve eCNAM data, the service provider formulates queries using a searchkey to retrieve the name and metadata. The searchkey is a user identity obtained from the incoming SIP INVITE. Most commonly, the service provider uses an E.164 TN as that searchkey. Other identities could be used to retrieve the eCNAM data.
If the terminating network determines that the telephone number's (or other identity's) presentation is restricted (i.e., not to be presented to the end user), the eCNAM data will also be restricted.
If the terminating network determines that the telephone number (or other identity's) presentation is not restricted (i.e., to be presented to the end user), the eCNAM data will also be presented to the end user with no restriction.
The eCNAM service can be provided after prior arrangement with the service provider.
The eCNAM service can be withdrawn at the subscriber's request or for administrative reasons.
eCNAM is a terminating service, however, the eCNAM operations rely on information received from the originating network.
If the originating user identity, such as the originating user's E.164 TN, is not delivered by the originating network to the terminating network, the terminating service provider will not be able to retrieve eCNAM data from the relevant data sources.
The originating network can support a verification capability, such as the number verification capability described in TS 24.229. Without a verification capability at the originating network, the integrity of the eCNAM data retrieved could be impacted.
The eCNAM service involves the retrieval of the name data and the additional caller information from data sources that the terminating service provider has access to, based on service provider policy.
The special arrangements and interfaces between the terminating service provider and the data sources are outside the scope of this document and are subject to operator procedures.
The service provider activates the eCNAM service at provisioning, upon the user's request.
The service provider deactivates the service at withdrawal upon the user's request.
No user configuration is defined in this release.
eCNAM is a terminating service; however, the eCNAM operations rely on information received from the originating network.
If the incoming INVITE does not include the user's E.164 TN in the "tel" URI or the 'user element' of the SIP URI, the terminating AS will not be able to retrieve eCNAM data from the relevant data sources. Based on service provider policy, the AS uses the E.164 TN in either the incoming From header field or the incoming P-Asserted-Identity header field to request eCNAM data from the trusted data sources.
If this information is not received in the incoming INVITE or is not available from the data sources (missing data or query timeouts) then the terminating AS shall consider the eCNAM data unavailable.
As a result, the terminating AS shall, according to local policy, populate the text string "Unavailable" in the "display-name" parameter of the outgoing From header field and/or P-Asserted-Identity header field in the SIP INVITE request that the terminating AS sends to the terminating UE.
If some elements of the eCNAM metadata are unavailable (e.g., requested data elements could not be found in the data source), the terminating AS shall deliver the available data to the terminating UE in Call-Info header fields, and shall not deliver the string "unavailable" for the missing elements.
If the terminating AS receives a Privacy header field set to any of the priv-values "id", "user" or "header" (i.e., presentation is not allowed), then the terminating AS shall populate the text string "Anonymous" in the "display-name" parameter of the From header field in the SIP INVITE request that the AS sends to the terminating UE. The full SIP URI for Anonymous User Identity is described in TS 23.003.
The metadata may be sent to the terminating UE, based on service provider policy.
The terminating AS shall consider that the user identity presentation is allowed when there is no Privacy header field in the received INVITE or a Privacy header field set to priv-value "none".
If the identity presentation is allowed and the result of the originating user identity verification performed (such as the verification resulting in the "verstat" tel URI parameter described in TS 24.229) shows the verification passed, the AS shall proceed to retrieve eCNAM data from the trusted sources.
The AS shall extract the originating identity from the incoming INVITE in order to formulate the query to the trusted data sources. It is based on service provider policy to decide whether the identity retrieved from the P-Asserted-Identity header field, the From header field or both with a priority order.
If the chosen identity is the E.164 TN, the following procedures shall apply:
The terminating AS shall extract the TN from the username portion of the incoming SIP URI request of the incoming From header field or P-Asserted-Identity header field, if user=phone parameter is present.
If user=phone is not present in the SIP URI, the terminating AS shall extract the TN from the tel URI of the incoming From header field or P-Asserted-Identity header field.
If both a SIP URI with user=phone present, and a tel URI are available, the terminating AS shall extract the TN from the tel URI of the incoming From header field or P-Asserted-Identity header field.
The terminating AS will query the appropriate data source(s) using the extracted TN.
The terminating AS shall populate the received name (retrieved from data sources) in the "display-name" parameter of the From header field or the P-Asserted-Identity header field in the INVITE request being sent to the UE.
The terminating AS shall populate the received metadata elements in one or more Call-Info header fields.
If other name information is received in the INVITE request , the terminating service provider local policy shall apply. The AS may discard the received name data.
If the originating user identity verification performed (such as the verification resulting in the "verstat" tel URI parameter described in TS 24.229) shows that verification failed, the terminating AS may deliver partial or no eCNAM information to the subscriber's UE.
As a result, and based on terminating service provider policy, the terminating AS may perform one or more of the following actions:
The AS may remove the display-name of the From header field or the P-Asserted-Identity header field in the INVITE request being sent to the UE;
The AS may populate a text string of the terminating service provider's choice in the display-name of the From header field or the P-Asserted-Identity header field in the INVITE request being sent to the UE. Examples of such strings include "Suspected Spam" or "Fake Number";
The AS may populate graphical symbols of the service provider's choice in one or more Call-Info header field(s) to the terminating UE. Examples include warning symbols and text.
The terminating UE shall support the receipt of one or more P-Asserted Identity header fields.
The terminating UE shall retrieve the originating user's name from the "display-name" parameter of the P-Asserted Identity header field or the "display-name" parameter of the From header field depending on the header used for determining the originating party identity.
The UE shall support receipt of one or more Call-Info header fields.
The terminating UE shall retrieve the metadata of the originating user from the Call-Info header fields.
For users that subscribe to both OIP and eCNAM, and subject to service provider policy, the name information retrieved through eCNAM may override any name information available via OIP.
Subject to service provider policy, eCNAM metadata and other OIP data may both be presented to the end user with or without individual marking to distinguish the eCNAM service data from other call information.
If a terminating party has the eCNAM service active and is notified that an incoming communication is waiting, then this terminating user shall receive the eCNAM data on the incoming session, if presentation is not restricted on that incoming session.
In general, CUG members do not communicate with users outside the group. However, if members were allowed to activate eCNAM and to receive calls from outside the group, then eCNAM data will be delivered based on the caller's OIR status.
The originating party's eCNAM data shall be transmitted to the CCBS customer's UE when the terminating party becomes free, and a CCBS communication is generated to the terminating party.
Subject to service provider policy, the terminating AS serving the diverted to user may optionally deliver the eCNAM data of a diverting user. The identity of the diverting user is obtained from the History-Info header field, as described in TS 24.604.
If the FA Pilot has eCNAM activated, incoming calls to the FA Pilot shall apply eCNAM to the members of the FA group.
Metadata that is obtained from analytics shall be based on the FA Pilot and not the individual members' identity.
For a user that subscribes to both PNM and eCNAM, both originating user identity and eCNAM identity data shall be delivered to the Personal Network UE that is configured to act as a Personal Network controller.