WebSocket only. Defines the buffer size in bytes for received frames on a WebSocket host. If this value is 0 (the default), a 4 kilobyte buffer is used. Any other value results in a buffer of that size, in bytes.
WebSocket message fragments are called "frames". A WebSocket host has a buffer to store incoming message frames. Therefore this buffer should be set to the largest legal frame size supported. If an incoming frame exceeds the buffer size, no error is reported. However, the buffer will invoke the user callback in order to create space for the overflow.