| OID | 1.3.6.1.2.1.127.1.2.1.17 |
| Module | DOCS-IETF-QOS-MIB (CISCO) |
| Nom | docsIetfQosParamSetTosAndMask |
| Acces | readonly |
| Status | current |
| Description | Specifies the AND mask for the IP TOS byte for
overwriting IP packet's TOS value. The IP packet
TOS byte is bitwise ANDed with
docsIetfQosParamSetTosAndMask, and the result is
bitwise ORed with docsIetfQosParamSetTosORMask and
the result is written to the IP packet TOS byte.
A value of 'FF'H for docsIetfQosParamSetTosAndMask
and a value of '00'H for
docsIetfQosParamSetTosOrMask means that the IP
Packet TOS byte is not overwritten.
This combination is reported if the referenced
parameter is not present in a QOS Parameter Set.
The IP TOS octet as originally defined in RFC 791
has been superseded by the 6-bit Differentiated
Services Field (DSField, RFC 3260) and the 2-bit
Explicit Congestion Notification Field (ECN field,
RFC 3168). Network operators SHOULD avoid
specifying values of docsIetfQosParamSetTosAndMask
and docsIetfQosParamSetTosORMask that would result
in the modification of the ECN bits.
In particular, operators should not use values of
docsIetfQosParamSetTosAndMask that have either of
the least-significant two bits set to 0. Similarly,
operators should not use values of
docsIetfQosParamSetTosORMask that have either of
the least-significant two bits set to 1.
Even though this object is only enforced by the
Cable Modem Termination System (CMTS),
Cable Modems MUST report the value as signaled in
the referenced parameter. |
| Syntaxe | OctetString (1...1) |
| Module | DOCS-IETF-QOS-MIB (ietf) |
| Nom | docsIetfQosParamSetTosAndMask |
| Acces | readonly |
| Status | current |
| Description | Specifies the AND mask for the IP TOS byte for
overwriting IP packet's TOS value. The IP packet
TOS byte is bitwise ANDed with
docsIetfQosParamSetTosAndMask, and the result is
bitwise ORed with docsIetfQosParamSetTosORMask and
the result is written to the IP packet TOS byte.
A value of 'FF'H for docsIetfQosParamSetTosAndMask
and a value of '00'H for
docsIetfQosParamSetTosOrMask means that the IP
Packet TOS byte is not overwritten.
This combination is reported if the referenced
parameter is not present in a QOS Parameter Set.
The IP TOS octet as originally defined in RFC 791
has been superseded by the 6-bit Differentiated
Services Field (DSField, RFC 3260) and the 2-bit
Explicit Congestion Notification Field (ECN field,
RFC 3168). Network operators SHOULD avoid
specifying values of docsIetfQosParamSetTosAndMask
and docsIetfQosParamSetTosORMask that would result
in the modification of the ECN bits.
In particular, operators should not use values of
docsIetfQosParamSetTosAndMask that have either of
the least-significant two bits set to 0. Similarly,
operators should not use values of
docsIetfQosParamSetTosORMask that have either of
the least-significant two bits set to 1.
Even though this object is only enforced by the
Cable Modem Termination System (CMTS),
Cable Modems MUST report the value as signaled in
the referenced parameter. |
| Syntaxe | OctetString (1...1) |