UDP Multicast for broadcasting messages to multiple receiving nodes?

Hi all,

I'm currently pursuing a Wireless Sensor Network (WSN) application using Arduino and ESP8266 modules. My WSN consists of 18 separate devices (1 Master and 17 slaves, so to speak). The master must be able to broadcast its data to the other 17 nodes at a rate of 50 (best case) to 26000 (worst case) packets/second per node. Each data packet has 4 bytes.

UDP multicast seems like a good option for me but I don't know what is the maximum number of nodes that I can add and whether its data throughput is fast enough for the job.