H3C WX5500H series User Configuration Manual

Also see for WX3000H series: Installation guide

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H3C WX5500H series User Configuration Manual Manual pdf 46 page image

38Port priority Local precedence4 45 56 67 7Appendix C Introduction to packet precedencesIP precedence and DSCP valuesFigure 9 ToS and DS fieldsAs shown in Figure 9, the ToS field in the IP header contains 8 bits. The first 3 bits (0 to 2) representIP precedence from 0 to 7. According to RFC 2474, the ToS field is redefined as the differentiatedservices (DS) field. A DSCP value is represented by the first 6 bits (0 to 5) of the DS field and is in therange 0 to 63. The remaining 2 bits (6 and 7) are reserved.Table 8 IP precedenceIP precedence (decimal) IP precedence (binary) Description0 000 Routine1 001 priority2 010 immediate3 011 flash4 100 flash-override5 101 critical6 110 internet7 111 networkTable 9 DSCP valuesDSCP value (decimal) DSCP value (binary) Description46 101110 ef10 001010 af1112 001100 af12MBZRFC 1122IP Type of Service (ToS)RFC 791MustBeZeroRFC 1349IPv4 ToSbyte0 761 5432Bits:PrecedenceType ofService0 76DSCPClass SelectorcodepointsDifferentiated ServicesCodepoint (DSCP)RFC 2474CurrentlyUnusedDS-Field(for IPv4,ToSoctet,and forIPv6,TrafficClass octet )1 5432Bits:CU