RSTP - Message Age

Question:

Someone knows, in RSTP, when one Cisco 1900 switch receive a BPDU, how does the switches manipulate the message age timer in RSTP? Does it modify the message age?

Answer:

In RSTP, each non-root switch receives a BPDU on its Root Port with the Message Age set to N, N>=0. As a result, the switch itself will send out its own BPDUs with the Message Age set to N+1. A root swich sends its BPDUs with the Message Age set to 0. Cisco3925E