Static simple jitter buffer dimensioning

Hi all, how can I choose the size (in frames or packets, provided they are always of the same size) of a simple static jitter buffer implemented as a ring buffer that can overflow or underflow (so, no menagement of timestamps) if I know the variance of the interarrival times?
The interarrival are very correlated because there are a lot of bursts ( a late packet and the subsequents all back to back).
If the distribution was normal and the interarrivals independents, I could have said that taking three times the standard deviation I catch the 99% of them…

Thanks in advance

Breezer