Maximum number of Switches allowed in an RSTP Ring, Mesh topology

[r20039r20039]

Hi

How many maximum number Switches are allowed in an RSTP environment in terms of Ring, Mesh topology?

What happens if anyone plugs in more switches than that number?

is there any official Cisco/IEEE documentation on this issue?

Thank you all 

[Milos Megis]

Hi, there is restriction for max 7 switches diameter. Distance between any 2 switches cannot be more then 7 devices.

Otherwise STP will not work correctly.