These are good references for VIPs involved in RAC VIP Concepts
They call the BDP a “product” because the value for BDP is indeed a multiplication of the average round-trip time and the total bandwidth of the network cable.
For example, if a network has a bandwidth of 100 megabytes per second and a round trip time of 5 milliseconds, the recv_buf_size and send_buf_size sqlnet.ora parameters values should be set to a value of at least 63k:
(100X106) * (5X10-3) bits ~= 63k:.
100,000,000 bits 1 byte 5 seconds
—————- x —— x ——— = 62,500 bytes
1 second 8 bits 1000
To prevent network contention, the values for recv_buf_size and send_buf_size should be set to the maximum amount of data that might be sent, at least 3x the value of your bandwidth delay product (BDP).
If you are tuning your network to maximize throughput (as opposed to tuning for fast response time), Oracle suggests setting recv_buf_size and send_buf_size sqlnet.ora parameters equal to 3 times the Bandwidth Delay Product (BDP).