PCC matcher will allow you to divide traffic into equal streams with ability to keep packets with specific set of options in one particular stream (you can specify this set of options from src-address, src-port, dst-address, dst-port)
PCC takes selected fields from IP header, and with the help of a hashing algorithm converts selected fields into 32-bit value. This value then is divided by a specified Denominator and the remainder then is compared to a specified Remainder, if equal then packet will be captured. You can choose from src-address, dst-address, src-port, dst-port from the header to use in this operation.
per-connection-classifier= PerConnectionClassifier ::= [!]ValuesToHash:Denominator/Remainder Remainder ::= 0..4294967295 (integer number) Denominator ::= 1..4294967295 (integer number) ValuesToHash ::= both-addresses|both-ports|dst-address-and-port| src-address|src-port|both-addresses-and-ports|dst-address|dst-port|src-address-and-port
This configuration will divide all connections into 3 groups based on source address and port
/ip firewall mangle add chain=prerouting action=mark-connection \ new-connection-mark=1st_conn per-connection-classifier=src-address-and-port:3/0 /ip firewall mangle add chain=prerouting action=mark-connection \ new-connection-mark=2nd_conn per-connection-classifier=src-address-and-port:3/1 /ip firewall mangle add chain=prerouting action=mark-connection \ new-connection-mark=3rd_conn per-connection-classifier=src-address-and-port:3/2
PCC is available in RouterOS since v3.24. This option was introduced to address configuration issues with load balancing over multiple gateways with masquerade