Glossary ======== .. glossary:: NUT Network Under Test. This is typically what you want to test with a ByteBlower Server. An example can be the CMTS - HFC network - Cable Modem setup. TOS :term:`Type of Service` Traffic Class :term:`Type of Service` Type of Service Both the IPv4 and IPv6 headers reserve space to specify the expected quality of service (QOS). IPv4 calls this field the 'Type Of Service'. In IPv6 one uses the term 'Traffic Class'. Despite naming, they are both 8 bits wide.