1     Introduction      
 2     References 
 3     Definitions  
 4     Abbreviations and acronyms        
 5     Conventions     
 6     Echo control in telecommunication networks         
        6.1     Echo control devices          
        6.2     General echo control considerations from a PSTN perspective       
        6.3     Additional echo control considerations from the perspective of interconnected networks                   (e.g., private networks, the Internet)     
        6.4     Application-related echo control considerations      
        6.5     Voiceband data modem constraints
 7     Application rules and operational constraints         
        7.1     Public network transmission planning          
        7.2     Delay considerations          
        7.3     Provisioning of the echo-path capacity and echo-path characteristics           
        7.4     Echo canceller transmission planning for multiple interconnected networks (e.g., public, private, Internet)     
 8     Network and service evolutionary considerations  
        8.1     Bit transparency of echo cancellers 
        8.2     Non-linearities and time-variant effects in the echo path      
        8.3     Low bit-rate coding between tandem cancellers      
        8.4     Tandeming of echo cancellers         
        8.5     Convergence speed           
        8.6     Acoustic echo control and environments     
        8.7     New circuit-switched service         
        8.8     Comfort noise        
 9     Special CME networking considerations  
        9.1     Detailed interaction
        9.2     Possible solutions   
Appendix I – Echo-path dispersion time     
        I.1        Echo-path characteristics from measurements in North America    
Appendix II – Multiple tail circuits     
       II.1     Multiple tails in a typical bridged telephone call (North America)