The value of tmnxOamIcmpPingCtlDSField specifies the value to load in
the Type of Service (TOS) octet or the Traffic Class (TC) octet of the
launched ICMP echo request(s). The TOS octet is a field in the IPv4
packet header. The TC octet is a field in the IPv6 packet header.
The value in the TOS or TC octet may influence the route, latency,
and/or probability of loss for the echo request (and, by inference,
for the associated data flow).
This object is optional.