MSTP actually uses RSTP for Rapid convergence.In fact, it enables VLANs to be grouped into a spanning-tree instance, provides for multiple forwarding paths for data traffic, and enables load balancing. So it is possible to use RSTP without using MSTP. The concept is like this: Either all VLANs can run PVST, or all VLANs can run MSTP. PVST, PVST+ and MST are supported , but only one version can be active at any time.To support this please go through the following document:
