Returns the ToS level of a packet. The Type of Service (ToS) standard is a means by which network equipment can identify and treat traffic differently based on an identifier. As traffic enters the site, the BIG-IP system can apply a rule that sends the traffic to different pools of servers based on the ToS level within a packet.
This is a BIG-IP version 4.X variable, provided for backward-compatibility. You can use the equivalent 9.X command IP::tos instead.