Restrictions for Configurable Number of Simultaneous Packets per Flow
-
When the TCP window scale option is configured, the firewall cannot simultaneously fit too many TCP packets per flow, and packets that exceed the configured limit are dropped. The maximum window size that can be used, if the TCP window scale option is enabled, is 1 GB.
The standard TCP window size is between 2 and 65,535 bytes. If the TCP payload size is smaller than 655 bytes, 100 simultaneous packets cannot contain all TCP packets that belong to a single TCP window, and this can result in packet drops. We recommend that you increase the TCP payload size or reduce the TCP window size to avoid packet drops.
-
The total available threads in each platform varies according to the enabled license levels. If the configured number of simultaneous packets per flow is bigger than the available hardware thread number, the configuration of simultaneous packets is not effective.