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    | Structure
    of Q.931 message (Release) 
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    | Message type: RELEASE 
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    | Significance: Local 
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    | Direction: Both 
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    | Info Element     Direction   Type   Length 
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    | Protocol
           Both      
    M     1 
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    | discriminator 
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    | Call
    reference       Both       M     2- 
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    | Message
    type       Both      
    M     1 
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    | Cause        
    Both      
    O      2-32 
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    | Display        
    n ®
    u       O 
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    | Signal        
    n ®
    u       O      2-3 
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    | Cause
    description may require many bytes 
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