AA TCPO implements the TCP new-reno stack toward the core network and TCPW, TCP BBR, or TCP Illinois configurable toward the access network.
AA TCPO does not modify or change the advertised MSS setting.
For interactions between AA TCPO and the rest of the AA feature set (such as policers), AA TCPO is logically implemented upstream from AA toward the core network. For example, if policing is enabled for a subscriber in the "from subscriber” direction, the subscriber packets are subjected to policing before any AA TCPO related action is applied to these packets. Similarly, "from subscriber" statistics maintain counts of flows before hitting the TCPO. On the other hand, in the downstream direction, the "to subscriber" statistics reflect post AA TCPO behavior, while "to subscriber" policing is applied to packets generated by AA TCPO toward the subscriber. The same concept applies to other AA features such as TCP performance measurements and HTTP enrichments.