Role of ENUM in IMS

When an end-user dials an E.164 number to establish an IMS (SIP) session, Carrier-ENUM provides the standardized infrastructure for the discovery of the IMS services associated with the dialed E.164 number regardless of whether or not the number has been ported. The role of ENUM in the delivery of IMS services is well documented within the relevant 3GPP IMS specifications.

• IMS Stage 2: TS 23.228 v6.5.0 – Section 4.3.5
• IMS Stage 3: TS 24.228 v5.9.0 – Section 7.3 and all IMS session initiation examples

For more information, contact NetNumber’s Business Development team and request a copy of the white paper: “Role of ENUM in IMS”. The audiences for this paper are wireless operators and equipment vendors working to deploy cross-operator, fixed-line carriers IMS services. Specific issues addressed in the document include:

• Carrier-ENUM solution that dramatically simplifies the addressing of SIP-based services like Push-to-talk, Presence and VoIP across multiple technology environments (GSM, CDMA and Fixed-line) and across multiple portability regions/countries.
  
  
• Carrier-ENUM architecture that enables an Operator to leverage existing number-portability solutions (central database, number-block assignment, IMSI query, etc.) to identify a portability-corrected destination carrier.
  
  
• Carrier-ENUM solution that can be implemented without requiring the use of any centralized ENUM registry or registrar services.

Cross-Operator IMS Example