CONTENTS

 1     Scope 
 2     References 
 3     Definitions  
 4     Conventions     
 5     Abbreviations   
        5.1     General abbreviations        
        5.2     RAS message abbreviations           
 6     Packetization and synchronization mechanism       
        6.1     General approach  
        6.2     Use of RTP/RTCP
 7     H.225.0 message definitions         
        7.1     Use of Q.931 messages     
        7.2     Common Q.931 information elements        
        7.3     Q.931 based H.225.0 call signalling message details           
        7.4     Q.932‑based H.225.0 call signalling message details          
        7.5     H.225.0 call signalling timer values 
        7.6     H.225.0 common message elements           
        7.7     Required support of RAS messages           
        7.8     Terminal and gateway discovery messages 
        7.9     Terminal and gateway registration messages           
       7.10     Terminal/gatekeeper unregistration messages         
       7.11     Terminal to gatekeeper admission messages          
       7.12     Terminal to gatekeeper requests for changes in bandwidth 
       7.13     Location request messages
       7.14     Disengage messages         
       7.15     Status request messages    
       7.16     Non-standard message     
       7.17     Message not understood   
       7.18     Gateway resource availability messages     
       7.19     RAS timers and Request in Progress (RIP)
       7.20     Service control messages  
       7.21     AdmissionConfirmSequence         
       7.22     Error Code Mapping        
 8     Mechanisms for maintaining QoS 
        8.1     General approach and assumptions
        8.2     Use of RTCP in measuring QoS     
        8.3     Audio/Video jitter procedures        
        8.4     Audio/Video skew procedures       
        8.5     Procedures for maintaining QoS     
        8.6     Echo control          
Annex A – RTP/RTCP    
Annex B – RTP profile    
Annex C – RTP payload format for H.261 video streams    
Annex D – RTP payload format for H.261A video streams    
        D.1     Introduction          
        D.2     H.261A RTP packetization           
Annex E – Video packetization    
        E.1     H.263    
Annex F – Audio and multiplexed packetization    
        F.1     G.723.1 
        F.2     G.728    
        F.3     G.729    
        F.4     Silence suppression           
        F.5     GSM codecs         
        F.6     G.722.1 
        F.7     TIA/EIA-136 ACELP       
        F.8     TIA/EIA-136 US1
        F.9     IS-127 EVRC       
       F.10     H.223 MUX-PDU packetization  
Annex G – Communication between and within administrative domains    
        G.1     Scope    
        G.2     Definitions 
        G.3     Abbreviations       
        G.4     Normative references        
        G.5     System models      
        G.6     Operation 
        G.7     Signalling examples           
        G.8     Annex G profiles   
Annex H – H.225.0 message syntax (ASN.1)    
Annex I – H.263+ video packetization    
Appendix I – RTP/RTCP algorithms    
      Page
Appendix II – RTP profile    

Appendix III – H.261 packetization    
Appendix IV – H.225.0 operation on different packet-based network protocol stacks    
       IV.1     TCP/IP/UDP        
       IV.2     SPX/IPX  
       IV.3     SCTP    
Appendix V – ASN.1 usage in this Recommendation    
        V.1     Tagging  
        V.2     Types    
        V.3     Constraints and ranges      
        V.4     Extensibility           
Appendix VI – H.225.0 identifiers of tunnelled signalling protocols