rfc1028.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

       said string.

   (2)  A variable name octet string may be represented
        symbolically by a character string whose form reflects
        the sequence of octets in said name while at the same
        time suggesting to a human reader the semantics of the
        named variable.

   Variable name octet strings are represented symbolically according to
   the following two rules:

   (1)  The symbolic character string representation of the
        variable name of zero length is the character string of
        zero length.

   (2)  The symbolic character string representation of a
        variable name of non-zero length n is the concatenation
        of the symbolic character string representation of the
        variable name formed by the first (n - 1) octets of the
        given name together with the underscore character ("_")
        and a character string that does not include the
        underscore character, such that the resulting character
        string is unique among the symbolic character string
        representations for all variable names of length n.





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   Thus, for example, the variable names represented numerically as:

                         01 01 01,
                         01 01 02,
                         01 02 01,
                         01 03 01 03 01,
                         01 03 01 03 02,
                         01 03 01 04 01, and
                         01 03 01 04 02

   might be represented symbolically by the character strings:

                         _GW_version_id,
                         _GW_version_rev,
                         _GW_cfg_nnets,
                         _GW_net_if_type_net1,
                         _GW_net_if_type_net2,
                         _GW_net_if_speed_net1, and
                         _GW_net_if_speed_net2.

   All variable names are terminated by an implementation specific octet
   string of non-zero length.  Thus, a complete variable name is not
   specified for any of the variables defined in this document.  Rather,
   for each defined variable, some prefix portion of its name is
   specified, with the understanding that the rightmost portion of its
   name is specific to the protocol implementation.

   Fullest exploitation of the semantics of the Get Request type message
   requires that names for related variables be chosen so as to be
   contiguous in the lexicographic ordering of all variable names
   recognized by an application protocol entity.  This principle is
   observed in the naming of variables currently defined by this
   document, and it should be observed as well for variables defined by
   subsequent revisions of this document and for variables introduced by
   particular implementations of the protocol.

   A particular implementation of a protocol entity may present
   variables in addition to those defined by this document, provided
   that in no case will an implementation-specific variable be presented
   as having a name identical to that for one of the variables defined
   here.  By convention, the names of variables specific to a particular
   implementation share a common prefix that distinguishes said
   variables from those defined in this document and from those that may
   be presented by other implementations of an application protocol
   entity.  For example, variables specific to an implementation of this
   protocol in version 1.3 of the Squeaky gateway product of the
   Swinging Gateway company might have the names represented by:




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RFC 1028               Simple Gateway Monitoring           November 1987


                 01 FF 01 01 13 01,
                 01 FF 01 01 13 02, and
                 01 FF 01 01 13 03,


   for which the corresponding symbolic representations might be:

                 _GW_impl_Swinging_Squeaky_v1.3_variableA,
                 _GW_impl_Swinging_Squeaky_v1.3_variableB, and
                 _GW_impl_Swinging_Squeaky_v1.3_variableC.

   The names and semantics of implementation-specific variables are not
   otherwise defined by this document, although implementors are
   encouraged to publish such definitions either as appendices to this
   document or by other appropriate means.

   Variable names of which the initial portion is represented
   numerically as 02 and symbolically as "_HOST" are reserved for future
   use.  Variable names of which the initial portion is represented
   numerically as 03 and symbolically as "_TS" are similarly reserved.

6.  Required Variables

   To the extent that the information represented by a variable defined
   in this section is also represented internally by a gateway for which
   this protocol is realized, access to that variable must be afforded
   by at least one application protocol entity associated with said
   gateway.

6.1.  The _GW_version_id Variable

   The variable such that the initial portion of its name is represented
   symbolically as "_GW_version_id" and numerically as:

                 01 01 01

   has an octet string value that identifies the protocol entity
   implementation (e.g., "ACME Packet-Whiz Model II").

6.2.  The _GW_version_rev Variable

   The variable such that the initial portion of its name is represented
   symbolically as "_GW_version_rev" and numerically as:

                 01 01 02

   has an integer value that identifies the revision level of the entity
   implementation.  The encoding of the revision level as an integer



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   value is implementation-specific.

6.3.  The _GW_cfg_nnets Variable

   The variable such that the initial portion of its name is represented
   symbolically as "_GW_cfg_nnets" and numerically as:

                 01 02 01

   has an integer value that represents the number of logical network
   interfaces afforded by the configuration of the gateway.

6.4.  Network Interface Variables

   This section describes a related set of variables that represent
   attributes of the logical network interfaces afforded by the gateway
   configuration.  Each such network interface is uniquely identified by
   an octet string.  The convention by which names are assigned to the
   network interfaces of a gateway is implementation-specific.

6.4.1.  The _GW_net_if_type Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_type" and numerically as:

                 01 03 01 03

   has an integer value that represents the type of the network
   interface identified by the remainder of the name for said variable.
   The value of a variable of this class represents network type
   according to the conventions described in Appendix 1.

6.4.2.  The _GW_net_if_speed Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_speed" and numerically as:

                 01 03 01 04

   has an integer value that represents the estimated nominal bandwidth
   in bits per second of the network interface identified by the
   remainder of the name for said variable.

6.4.3.  The _GW_net_if_in_pkts Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_in_pkts" and numerically as:




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                 01 03 01 01 01

   has an integer value that represents the number of packets received
   by the gateway over the network interface identified by the remainder
   of the name for said variable.

6.4.4.  The _GW_net_if_out_pkts Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_out_pkts" and numerically as:

                 01 03 01 02 01

   has an integer value that represents the number of packets
   transmitted by the gateway over the network interface identified by
   the remainder of the name for said variable.

6.4.5.  The _GW_net_if_in_bytes Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_in_bytes" and numerically as:

                 01 03 01 01 02

   has an integer value that represents the number of octets received by
   the gateway over the network interface identified by the remainder of
   the name for said variable.

6.4.6.  The _GW_net_if_out_bytes Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_out_bytes" and numerically as:

                 01 03 01 02 02

   has an integer value that represents the number of octets transmitted
   by the gateway over the network interface identified by the remainder
   of the name for said variable.

6.4.7.  The _GW_net_if_in_errors Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_in_errors" and numerically as:

                 01 03 01 01 03

   has an integer value that represents the number of reception errors
   encountered by the gateway on the network interface identified by the



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   remainder of the name for said variable.  The definition of a
   reception error is implementation-specific and may vary according to
   network type.

6.4.8.  The _GW_net_if_out_errors Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_out_errors" and numerically as:

                01 03 01 02 03

   has an integer value that represents the number of transmission
   errors encountered by the gateway on the network interface identified
   by the remainder of the name for said variable.  The definition of a
   transmission error is implementation-specific and may vary according
   to network type.

6.4.9.  The _GW_net_if_status Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_net_if_status" and numerically as:

                 01 03 01 05

   has an integer value that represents the current status of the
   network interface identified by the remainder of the name for said
   variable.  Network status is represented according to the conventions
   described in Appendix 2.

6.5.  Internet Protocol Variables

   This section describes variables that represent information related
   to protocols and mechanisms of the Internet Protocol (IP) family [3].

6.5.1.  Protocol Address Variable Classes

   This section describes a related set of variables that represent
   attributes of the the IP interfaces presented by a gateway on the
   various networks to which it is attached.  Each such protocol
   interface is uniquely identified by an octet string.  The convention
   by which names are assigned to the protocol interfaces for a gateway
   is implementation-specific.

6.5.1.1.  The _GW_pr_in_addr_value Variable Class

   A variable such that the initial portion of its name is represented
   symbolically as "_GW_pr_in_addr_value" and numerically as:




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                 01 04 01 01 01

   has an octet string value that literally represents the 32-bit
   Internet address for the IP interface identified by the remainder of
   the name for said variable.

6.5.1.2.  The _GW_pr_in_addr_scope Variable Class