1     Scope
 2     References
 3     Definitions
 4     Description of model
        4.1     Overview
        4.2     Echo control requirements
        4.3     Round-trip delay criteria
        4.4     Modem impedance requirements
        4.5     Model limitations
        4.6     Digital impairment requirements
        4.7     Network Model Coverage (NMC)
 5     Impairment level set-up
Annex  A  –  Attenuation and envelope delay distortion characteristics
Annex  B  –  Minimizing test time
Appendix  I  –  Rare intracontinental network model
        I.1     Model description
Appendix  II  –  Basis for network models
Appendix  III  –  Error rate vs. network model coverage
      III.1     Bit- and block-error rate vs. network model coverage
Appendix  IV  –  Supplemental round trip delay model