Systems and methods are described herein generally relating to network security, and in particular, embodiments described generally relate to systems and methods for selecting microservices to process protocol data streams. For example, a method is disclosed, which calls for receiving a protocol packet, the protocol packet comprising a sequence number, generating a difference by subtracting a protocol message base from the sequence number, generating a first quotient by dividing the difference by a protocol common message length, generating a second value using the first quotient, determining a Transmission Control Protocol (TCP) reassembly resource using the generated second value, and transmitting the protocol packet to the determined TCP reassembly resource.