Exhibit 10.2.3
 Amendment No. 67 (CA)
    
    April 1, 2008SOW:
    
    o Yesþ No
 
 AMENDMENT NO. 67
 FOR
 NOTICES AND PROJECT EXECUTIVE UPDATE
 UNDER
 CONTRACTOR SERVICES AGREEMENT FOR NUMBERING
 ADMINISTRATION CENTER / SERVICE MANAGEMENT
 SYSTEM
 CONFIDENTIAL




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Amendment No. 67 (CA)
    
    April 1, 2008SOW:
    
    o Yesþ No
 AMENDMENT NO. 67
 UNDER
 CONTRACTOR SERVICES AGREEMENT FOR NUMBERING
ADMINISTRATION CENTER / SERVICE MANAGEMENT SYSTEM
 Notices
and Project Executive Update
 1. PARTIES
 Amendment Master
Agreement Contractor Customer
 2. EFFECTIVENESS
 st Amendment
Effective Date
 3. UPDATES
 Notices
  If to Customer:
    
    To the Customer Project Executive at the address set forth in
Exhibit Iwith a copy to:
    
    Jacques R. Sarrazin, PresidentCanadian LNP Consortium Inc.6 Eagle Chase CourtNepean, OntarioK2J 3N5Tel: (613) 823-0144Fax: (613) 823-1169Email: jr.sarrazin@rogers.com
 CONFIDENTIAL




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Amendment No. 67 (CA)
    
    April 1, 2008SOW:
    
    o Yesþ No
 with a copy to:
    
    J. Scott FletcherGowling Lafleur Henderson LLPBarristers and Solicitors2600  160 Elgin StreetOttawa, OntarioK1P 1C3Tel: (613) 786-0167Fax: (613) 563-9869Email: scott.fletcher@gowlings.comIf to Contractor:
    
    To the Contractor Project Executive at the address set forth in
Exhibit Iwith a copy to:
    
    NeuStar Inc.Attn: Michael OConnor, VP, Customer Relations46000 Center Oak PlazaSterling, Virgina USA 20166Tel: (571) 434-5540Fax: (631) 376-0849with a copy to:
    
    NeuStar Inc.Attn: General Counsel46000 Center Oak PlazaSterling, Virginia USA 20166Fax: (571) 434-5735
   4. APPLICABLE DOCUMENTS
  N/A
    
    Functional Requirements SpecificationsN/A
    
    Requirements Traceability MatrixN/A
    
    External DesignN/A
    
    System DesignN/A
    
    Detailed DesignN/A
    
    Integration Test PlanN/A
    
    System Test PlanN/A
    
    Software Quality Assurance Program ReportN/A
    
    User Documentation
 CONFIDENTIAL




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Amendment No. 67 (CA)
    
    April 1, 2008SOW:
    
    o Yesþ No
 N/A
    
    Software Configuration Management PlanN/A
    
    Standards and Metrics
 5. IMPACTS ON MASTER AGREEMENT
  þ
    
    Master AgreementNone
    
    Exhibit B Functional Requirements SpecificationNone
    
    Exhibit C Interoperable Interface SpecificationNone
    
    Exhibit E Pricing SchedulesNone
    
    Exhibit F Project Plan and Test ScheduleNone
    
    Exhibit G Service Level RequirementsNone
    
    Exhibit H Reporting and Monitoring Requirementsþ
    
    Exhibit I Key PersonnelNone
    
    Exhibit J User Agreement FormNone
    
    Exhibit K External DesignNone
    
    Exhibit L Infrastructure/HardwareNone
    
    Exhibit M Software Escrow AgreementNone
    
    Exhibit O Statement of Work Cost Principles
 6. MISCELLANEOUS
 Counterparts
  Continuation of Master Agreement and User Agreement
  CONFIDENTIAL




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Amendment No. 67 (CA)
    
    April 1, 2008SOW:
    
    o Yesþ No
   [THIS SPACE INTENTIONALLY LEFT BLANK]
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Amendment No. 67 (CA)
    
    April 1, 2008SOW:
    
    o Yesþ No
  CONTRACTOR:NeuStar, Inc.Signature:
    /s/  Michael O ConnorName: Michael O ConnorTitle:   VP   Customer RelationsDate:   29 April 2008 CUSTOMER:Canadian LNP Consortium Inc.Signature:
    /s/ J.R. SarrazinName:
    J.R. SarrazinTitle:
    PresidentDate:
    April 28/2008 Page 6CONFIDENTIAL




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Amendment No. 67 (CA)
    
    April 1, 2008SOW:
    
    o Yesþ No
  ATTACHMENT 1
 TO
 AMENDMENT NO. 67
 Update to Exhibit I
 Page 7CONFIDENTIAL




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Amendment No. 67 (CA)
    
    April 1, 2008SOW:
    
    o Yesþ No
 EXHIBIT I
KEY PERSONNEL
    NeuStar Inc.      David.Garner@neustar.biz
     Canadian LNP Consortium Inc.      hearn@clnpc.ca
   Page 8CONFIDENTIAL