TOS significates "Type of service" and represents the 2nd byte in the IP datagramm. TOS usually refers to "Quality of Service" in packet networks.
Traditionally, the first three IP precedence (-> RFC 791) bits were supposed to be used in TOS Application Routing (RFC 1583-> OSPF, IS-IS) but no application really supports it. The TOS field has then been redefined as the Differentiated Services Code Point (DSCP-> RFC 2474) which consists of the first 6 bits and 2 bits used for a TCP mechanism called Explicit Congestion Notification (ECN) defined in RFC 3168.
The value 160 (Binary 10100000) means IP precedence 5 (Binary 101) or DSCP Class Selector 5 (Binary 101000 = 0x28).
In order to obtain low-delay, low-jitter, low-loss service Expedited Forwarding should be used instead (= 184):
|IP Prec||IP Prec Bin||DSCP Class||DSCP Bin||DSCP Hex||DCSP Dec||TOS value (snom)|