RADIUS Client – UDP Source Port Generation Logic
The following logic is used for generating a UDP source port.

3 Bits - Reserved for future use
6 Bits - Maximum number of 64 replica instances
7 Bits - Maximum number of 128 source ports per instance
x 256 IDs - Maximum number of 32 outstanding RADIUS requests per instance
13 Bits Total - Maximum number of 8000 source ports per instance
x 256 IDs - Maximum number of 2 million outstanding RADIUS requests per cluster