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ITU Workshop on “Caller ID Spoofing”

Geneva, Switzerland, 2 June 2014 (P.M.)



The International Telecommunication Union (ITU) will convene a half-day (afternoon) workshop on “Caller ID Spoofing” at ITU Headquarters in Geneva, Switzerland, on Monday 2 June 2014.  This workshop will be held in conjunction with the ITU-T Study Group 2 meeting due to take place from 28 May to 6 June 2014.


Caller ID spoofing issue is an important topic for ITU which is emphasized in WTSA-12 Resolution 65 on Calling Party Number Delivery, Calling Line Identification and Origin Identification, as well as in WTSA-12 Resolution 29 on Alternative Calling Procedure, PP-06 Resolution 21 on Alternative Calling Procedures on Telecommunication Networks,  and WTDC-10 Resolution 22 on Alternative Calling Procedures on International Telecommunication Networks, Identification of Origin and Apportionment of Revenues, in Providing International Telecommunication Services. It is also included in International Telecommunication Regulations where it is stated that Member States shall endeavor to ensure that international Calling Line Identification (CLI) information is provided taking into account the relevant ITU-T Recommendations.  Additionally WTSA-12 requested ITU-T SG2 and SG3 and possibly SG17, according to their mandates, to study the impact of non-origin identification and spoofing, including economic and security impact.

ITU-T SG2 has approved Recommendation ITU-T E.157 ( ) which requests the delivery of calling party numbers across international boundaries and provides guidance on which number and in what format should an E.164 number be delivered as a calling party number. To respond to the above mentioned Resolutions and Articles, E.157 is now under review and could be revised accordingly. ITU-T SG11 (e.g. Q.931) and SG16 (e.g. H.323) also maintain some Recommendations which are related or potentially related to calling line identification issue. PKI (X.509) under ITU-T SG 17 is considered to be used for securing SIP channel signaling to ensure telephone numbers are used by authorized parties as stated in draft-peterson-stir-certificates-00 (

Caller ID spoofing can happen in cases of PSTN-PSTN, and with higher potential, in IP-PSTN, IP-IP, IP-PSTN-IP, as analyzed in the IETF document  draft-ietf-stir-threats-00.txt ( 1).

 1) See also a media article on the spoofing issue:


The main objective of this workshop is to present the current status of this issue in both of the PSTN and IP environments, and the relevant activities within and outside ITU-T, and to share experiences, analyze and discuss the issue from both technical and regulatory aspects, and to consider proposals on future activities and the potential of cooperation, based on a comprehensive understanding of this issue that could be achieved through this workshop.

Target Audience

The event will bring together Participants from ITU-T Study Group 2 and experts from member states, regulators, operators, vendors and service providers who are interested in this topic.  



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