When greeting someone, are there any subtle differences between "Ave" and "Salve"? Can both be used to greet and respond? E.g.

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> Marcus: Ave, Cicero.
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> Cicero: Salve, Marce.
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> 
> 

Or, vice versa:

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> Vergilius: Salve, Ovidi.
> 
> 
> Ovidius: Ave, Vergili.
> 
> 
> 

Furthermore, is one in a higher register than the other? Would one be used more often by plebeians? Or by aristocrats?