and breaks it up into separate classes. It might very well contain
fourteen classifier elements indicating the twelve AFmn DSCP values,
EF, and "everything else". These would presumably direct traffic
down six functional data paths: one for each AF or EF class, and one
for all other traffic.
3.6.1.2. AF Implementation On an Ingress Edge Interface
Each AFm class applies a Two Rate Three Color Meter, dividing traffic
into three groups. These groups of traffic conform to both specified
rates, only the higher one, or none. The intent, on the ingress
interface at the edge of the network, is to measure and appropriately
mark traffic.
3.6.1.2.1. AF Metering On an Ingress Edge Interface
Each AFm class applies a Two Rate Three Color Meter, dividing traffic
into three groups. If two rates R and S, where R < S, are specified
and traffic arrives at rate T, traffic comprising up to R bits per
second is considered to conform to the "confirmed" rate, R. If
R < T, traffic comprising up to S-R bits per second is considered to
conform to the "excess" rate, S. Any further excess is non-
conformant.
Two meter entries are used to configure this, one for the conforming
rate and one for the excess rate. The rate parameters are stored in
associated Token Bucket Parameter Entries. The "FailNext" pointer of
the lower rate Meter Entry points to the other Meter Entry; both
"SucceedNext" pointers and the "FailNext" pointer of the higher Meter
Entry point to lists of actions. In the color-blind mode, all three
classifier "next" entries point to the lower rate meter entry. In
the color-aware mode, the AFm1 classifier points to the lower rate
entry, the AFm2 classifier points to the higher rate entry (as it is
only compared against that rate), and the AFm3 classifier points
directly to the actions taken when both rates fail.
3.6.1.2.2. AF Actions On an Ingress Edge Interface
For network planning and perhaps for billing purposes, arriving
traffic is normally counted. Therefore, a "count" action, consisting
of an action table entry pointing to a count table entry, is
configured.
Also, traffic is marked with the appropriate DSCP. The first R bits
per second are marked AFm1, the next S-R bits per second are marked
AFm2, and the rest is marked AFm3. It may be that traffic is
arriving marked with the same DSCP, but in general, the additional
complexity of deciding that it is being remarked to the same value is
not useful. Therefore, a "mark" action, consisting of an action
table entry pointing to a mark table entry, is configured.
At this point, the usual case is that traffic is now forwarded in the
usual manner. To indicate this, the "SucceedNext" pointer of the
Mark Action is set to zeroDotZero.
3.6.1.3. EF Implementation On an Ingress Edge Interface
The EF class applies a Single Rate Two Color Meter, dividing traffic
into "conforming" and "excess" groups. The intent, on the ingress
interface at the edge of the network, is to measure and appropriately
mark conforming traffic and drop the excess.
3.6.1.3.1. EF Metering On an Ingress Edge Interface
A single rate two color (srTCM) meter requires one token bucket. It
is therefore configured using a single meter entry with a
corresponding Token Bucket Parameter Entry. Arriving traffic either
"succeeds" or "fails".
3.6.1.3.2. EF Actions On an Ingress Edge Interface
For network planning and perhaps for billing purposes, arriving
traffic that conforms to the meter is normally counted. Therefore, a
"count" action, consisting of an action table entry pointing to a
count table entry, is configured.
Also, traffic is (re)marked with the EF DSCP. Therefore, a "mark"
action, consisting of an action table entry pointing to a mark table
entry, is configured.
At this point, the successful traffic is now forwarded in the usual
manner. To indicate this, the "SucceedNext" pointer of the Mark
Action is set to zeroDotZero.
Traffic that exceeded the arrival policy, however, is to be dropped.
One can use a count action on this traffic if the several counters
are interesting. However, since the drop counter in the Algorithmic
Drop Entry will count packets dropped, this is not clearly necessary.
An Algorithmic Drop Entry of the type "alwaysDrop" with no successor
is sufficient.
3.7. AF and EF Egress Edge Interface Configuration
3.7.1. Classification On an Egress Edge Interface
A packet arriving at an egress interface may have been classified on
an ingress interface, and the egress interface may have access to
that information. If it is relevant, there is no reason not to use
that information. If it is not available, however, there may be a
need to (re)classify on the egress interface. In any event, it picks
up its "program" from the diffServDataPathTable. This points to a
classifier, which will select traffic according to some specification
for each traffic class.
+-----------------------+
| diffServDataPathStart |
+-----------+-----------+
|
+----------+
|
+--+--+ +-----+ +-----+ +-----+ +-----+
| AF1 +-----+ AF2 +-----+ AF3 +-----+ AF4 +-----+ EF |
+-+++-+ +-+++-+ +-+++-+ +-+++-+ +-+-+-+
||| ||| ||| ||| | |
+-+++-+ +-+++-+ +-+++-+ +-+++-+ +-+-+-+
|trTCM| |trTCM| |trTCM| |trTCM| |srTCM|
|Meter| |Meter| |Meter| |Meter| |Meter|
+-+++-+ +-+++-+ +-+++-+ +-+++-+ +-+-+-+
||| ||| ||| ||| | |
+-+||---+ +-+||---+ +-+||---+ +-+||---+ +-+-|---+
|+-+|----+ |+-+|----+ |+-+|----+ |+-+|----+ |+--+----+
||+-+-----+ ||+-+-----+ ||+-+-----+ ||+-+-----+ ||Actions|
+||Actions| +||Actions| +||Actions| +||Actions| +| |
+| | +| | +| | +| | +-+-----+
+-+-----+ +-+-----+ +-+-----+ +-+-----+ |
||| ||| ||| ||| |
+-+++--+ +-+++--+ +-+++--+ +-+++--+ +--+---+
| Queue| | Queue| | Queue| | Queue| | Queue|
+--+---+ +--+---+ +--+---+ +--+---+ +--+---+
| | | | |
+--+-----------+-----------+-----------+---+ |
| WFQ/WRR Scheduler | |
+--------------------------------------+---+ |
| |
+-----+-----------+----+
| Priority Scheduler |
+----------+-----------+
|
V
Figure 8: combined EF and AF implementation
An example of a classifier for an AFm class would be a succession of
three classifier elements, each pointing to a Multi-field
classification parameter block identifying one of the AFmn DSCPs.
Alternatively, the filter might contain selectors for HTTP traffic or
some other application.
An example of a classifier for EF traffic might be either a
classifier element pointing to a Multi-field parameter specifying the
EF code point, or a collection of classifiers with parameter blocks
specifying individual telephone calls, or a variety of other
approaches.
Each classifier delivers traffic to appropriate functional data path
elements.
3.7.2. AF Implementation On an Egress Edge Interface
Each AFm class applies a Two Rate Three Color Meter, dividing traffic
into three groups. These groups of traffic conform to both specified
rates, only the higher one, or none. The intent, on the ingress
interface at the edge of the network, is to measure and appropriately
mark traffic.
3.7.2.1. AF Metering On an Egress Edge Interface
Each AFm class applies a Two Rate Three Color Meter, dividing traffic
into three groups. If two rates R and S, where R < S, are specified
and traffic arrives at rate T, traffic comprising up to R bits per
second is considered to conform to the "confirmed" rate, R. If
R < T, traffic comprising up to S-R bits per second is considered to
conform to the "excess" rate, S. Any further excess is non-
conformant.
Two meter entries are used to configure this, one for the conforming
rate and one for the excess rate. The rate parameters are stored in
associated Token Bucket Parameter Entries. The "FailNext" pointer of
the lower rate Meter Entry points to the other Meter Entry; both
"SucceedNext" pointers and the "FailNext" pointer of the higher Meter
Entry point to lists of actions. In the color-blind mode, all three
classifier "next" entries point to the lower rate meter entry. In
the color-aware mode, the AFm1 classifier points to the lower rate
entry, the AFm2 classifier points to the higher rate entry (as it is
only compared against that rate), and the AFm3 classifier points
directly to the actions taken when both rates fail.
+-----------------------------------------------------+
| Classifier |
+--------+--------------------------------------------+
|Green| Yellow| Red
| | |
+--+-----+-------+--+ Fail +--------------------+
| Meter +------+ Meter |
+--+----------------+ +---+-------+--------+
| Succeed (Green) | |Fail (Red)
| +---------+ |
| | Succeed (Yellow)|
+----+----+ +----+----+ +----+----+
| Count | | Count | | Count |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
|Mark AFx1| |Mark AFx2| |Mark AFx3|
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
| Random | | Random | | Random |
| Drop | | Drop | | Drop |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+--------+-----------------+-----------------+--------+
| Queue |
+--------------------------+--------------------------+
|
+----+----+
| Rate |
|Scheduler|
+----+----+
|
Figure 9a: Typical AF Edge egress interface configuration,
using color-blind meters
+-----------------------------------------------------+
| Classifier |
+--------+--------------------------------------------+
|Green | Yellow | Red
| | |
+----+----+ +----+----+ |
| Count | | Count | |
| Action +-------+ Action +------------+
+----+----+ Fail +----+----+ Fail |
|Succeed |Succeed |
+----+----+ +----+----+ +----+----+
| Count | | Count | | Count |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
|Mark AFx1| |Mark AFx2| |Mark AFx3|
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
| Random | | Random | | Random |
| Drop | | Drop | | Drop |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+--------+-----------------+-----------------+--------+
| Queue |
+--------------------------+--------------------------+
|
+----+----+
| Rate |
|Scheduler|
+----+----+
|
Figure 9b: Typical AF Edge egress interface configuration,
using color-aware meters
+-----------------------------------------------------+
| Classifier |
+--------+-----------------+-----------------+--------+
| Green | Yellow | Red
| | |
+----+----+ +----+----+ +----+----+
| Count | | Count | | Count |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+----+----+ +----+----+ +----+----+
| Random | | Random | | Random |
| Drop | | Drop | | Drop |
| Action | | Action | | Action |
+----+----+ +----+----+ +----+----+
| | |
+--------+-----------------+-----------------+--------+
| Queue |
+--------------------------+--------------------------+
|
+----+----+
| Rate |
|Scheduler|
+----+----+
|
Figure 10: Typical AF Edge core interface configuration
3.7.2.2. AF Actions On an Egress Edge Interface
For network planning and perhaps for billing purposes, departing
traffic is normally counted. Therefore, a "count" action, consisting
of an action table entry pointing to a count table entry, is
configured.
Also, traffic may be marked with an appropriate DSCP. The first R
bits per second are marked AFm1, the next S-R bits per second are
marked AFm2, and the rest is marked AFm3. It may be that traffic is
arriving marked with the same DSCP, but in general, the additional
complexity of deciding that it is being remarked to the same value is
not useful. Therefore, a "mark" action, consisting of an action
table entry pointing to a mark table entry, is configured.
At this point, the usual case is that traffic is now queued for
transmission. The queue uses Active Queue Management, using an
algorithm such as RED. Therefore, an Algorithmic Dropper is
configured for each AFmn traffic stream, with a slightly lower min-
threshold (and possibly lower max-threshold) for the excess traffic
than for the committed traffic.
3.7.2.3. AF Rate-based Queuing On an Egress Edge Interface
The queue expected by AF is normally a work-conserving queue. It
usually has a specified minimum rate, and may have a maximum rate
below the bandwidth of the interface. In concept, it will use as
much bandwidth as is available to it, but assure the lower bound.
Common ways to implement this include various forms of Weighted Fair
Queuing (WFQ) or Weighted Round Robin (WRR). Integrated over a
longer interval, these give each class a predictable throughput rate.
They differ in that over short intervals they will order traffic
differently. In general, traffic classes that keep traffic in queue
will tend to absorb latency from queues with lower mean occupancy, in
exchange for which they make use of any available capacity.
3.7.3. EF Implementation On an Egress Edge Interface
The EF class applies a Single Rate Two Color Meter, dividing traffic
into "conforming" and "excess" groups. The intent, on the egress
interface at the edge of the network, is to measure and appropriately
mark conforming traffic and drop the excess.
3.7.3.1. EF Metering On an Egress Edge Interface
A single rate two color (srTCM) meter requires one token bucket. It
is therefore configured using a single meter entry with a
corresponding Token Bucket Parameter Entry. Arriving traffic either
"succeeds" or "fails".
3.7.3.2. EF Actions On an Egress Edge Interface
For network planning and perhaps for billing purposes, departing
traffic that conforms to the meter is normally counted. Therefore, a
"count" action, consisting of an action table entry pointing to a
count table entry, is configured.
Also, traffic is (re)marked with the EF DSCP. Therefore, a "mark"
action, consisting of an action table entry pointing to a mark table
entry, is configured.
+-----------------------------------------------------+
| Classifier |
+-------------------------+---------------------------+
| Voice
|
+-------------+----------+
| Meter |
+----+-------------+-----+
| Succeed | Fail
| |
+----+----+ +----+----+
| Count | | Always |
| Action | | Drop |
+----+----+ | Action |
| +---------+
+----+---------+
| Algorithmic |
| Drop Action |
+----+---------+
|
+----------------+---------------+
| Queue |
+----------------+---------------+
|
+-----+-----+
| Priority |
| Scheduler |
+-----+-----+
Figure 11: Typical EF Edge (Policing) Configuration
+--------------------------------+
| Classifier |
+----------------+---------------+
| Voice
|
+----+----+
| Count |
| Action |
+----+----+
|
+------+-------+
| Algorithmic |
| Drop Action |
+------+-------+
|
+----------------+---------------+
| Queue |
+----------------+---------------+
|
+-----+-----+
| Priority |
| Scheduler |
+-----+-----+
Figure 12: Typical EF Core interface Configuration
At this point, the successful traffic is now queued for transmission,
using a priority queue or perhaps a rate-based queue with significant
over-provision. Since the amount of traffic present is known, one
might not drop from this queue at all.
Traffic that exceeded the policy, however, is dropped. A count
action can be used on this traffic if the several counters are
interesting. However, since the drop counter in the Algorithmic Drop
Entry will count packets dropped, this is not clearly necessary. An
Algorithmic Drop Entry of the type "alwaysDrop" with no successor is
sufficient.
3.7.3.3. EF Priority Queuing On an Egress Edge Interface
The normal implementation is a priority queue, to minimize induced
jitter. A separate queue is used for each EF class, with a strict
ordering.
4. Conventions used in this MIB
4.1. The use of RowPointer to indicate data path linkage
RowPointer is a textual convention used to identify a conceptual row
in a MIB Table by pointing to one of its objects. One of the ways
this MIB uses it is to indicate succession, pointing to data path
linkage table entries.
For succession, it answers the question "what happens next?". Rather
than presume that the next table must be as specified in the
conceptual model [MODEL] and providing its index, the RowPointer
takes you to the MIB row representing that thing. In the
diffServMeterTable, for example, the diffServMeterFailNext RowPointer
might take you to another meter, while the diffServMeterSucceedNext
RowPointer would take you to an action.
Since a RowPointer is not tied to any specific object except by the
value it contains, it is possible and acceptable to use RowPointers
to merge data paths. An obvious example of such a use is in the
classifier: traffic matching the DSCPs AF11, AF12, and AF13 might be
presented to the same meter in order to perform the processing
described in the Assured Forwarding PHB. Another use would be to
merge data paths from several interfaces; if they represent a single
service contract, having them share a common set of counters and
common policy may be a desirable configuration. Note well, however,
that such configurations may have related implementation issues - if
Differentiated Services processing for the interfaces is implemented
in multiple forwarding engines, the engines will need to communicate
if they are to implement such a feature. An implementation that
fails to provide this capability is not considered to have failed the
intention of this MIB or of the [MODEL]; an implementation that does
provide it is not considered superior from a standards perspective.
NOTE -- the RowPointer construct is used to connect the functional
data paths. The [MODEL] describes these as TCBs, as an aid to
understanding. This MIB, however, does not model TCBs directly.
It operates at a lower level of abstraction using only individual
elements, connected in succession by RowPointers. Therefore, the
concept of TCBs enclosing individual Functional Data Path elements
is not directly applicable to this MIB, although management tools
that use this MIB may employ such a concept.
It is possible that a path through a device following a set of
RowPointers is indeterminate i.e. it ends in a dangling RowPointer.
Guidance is provided in the MIB module's DESCRIPTION-clause for each
of the linkage attribute. In general, for both zeroDotZero and
dangling RowPointer, it is assumed the data path ends and the traffic
should be given to the next logical part of the device, usually a
forwarding process or a transmission engine, or the proverbial bit-
bucket. Any variation from this usage is indicated by the attribute
affected.
4.2. The use of RowPointer to indicate parameters
RowPointer is also used in this MIB to indicate parameterization, for
pointing to parameterization table entries.
For indirection (as in the diffServClfrElementTable), the idea is to
allow other MIBs, including proprietary ones, to define new and
arcane filters - MAC headers, IPv4 and IPv6 headers, BGP Communities
and all sorts of other things - while still utilizing the structures
of this MIB. This is a form of class inheritance (in "object
oriented" language): it allows base object definitions ("classes") to
be extended in proprietary or standard ways, in the future, by other
documents.
RowPointer also clearly indicates the identified conceptual row's
content does not change, hence they can be simultaneously used and
pointed to, by more than one data path linkage table entries. The
identification of RowPointer allows higher level policy mechanisms to
take advantage of this characteristic.
4.3. Conceptual row creation and deletion
A number of conceptual tables defined in this MIB use as an index an
arbitrary integer value, unique across the scope of the agent. In
order to help with multi-manager row-creation problems, a mechanism
must be provided to allow a manager to obtain unique values for such
an index and to ensure that, when used, the manager knows whether it
got what it wanted or not.
Typically, such a table has an associated NextFree variable e.g.
diffServClfrNextFree which provides a suitable value for the index of
the next row to be created e.g. diffServClfrId. The value zero is
used to indicate that the agent can configure no more entries. The
table also has a columnar Status attribute with RowStatus syntax [RFC
2579].
Generally, if a manager attempts to create a row, the agent will
create the row and return success. If the agent has insufficient
resources or such a row already exists, then it returns an error. A
manager must be prepared to try again in such circumstances, probably
by re-reading the NextFree to obtain a new index value in case a
second manager had got in between the first manager's read of the
NextFree value and the first manager's row-creation attempt.
To simplify management creation and deletion of rows in this MIB, the
agent is expected to assist in maintaining its consistency. It may
accomplish this by maintaining internal usage counters for any row
that might be pointed to by a RowPointer, or by any equivalent means.
When a RowPointer is created or written, and the row it points to
does not exist, the SET returns an inconsistentValue error. When a
RowStatus variable is set to 'destroy' but the usage counter is non-
zero, the SET returns no error but the indicated row is left intact.
The agent should later remove the row in the event that the usage
counter becomes zero.
The use of RowStatus is covered in more detail in [RFC2579].
5. Extending this MIB
With the structures of this MIB divided into data path linkage tables
and parameterization tables, and with the use of RowPointer, new data
path linkage and parameterization tables can be defined in other MIB
modules, and used with tables defined in this MIB. This MIB does not
limit the type of entries its RowPointer attributes can point to,
hence new functional data path elements can be defined in other MIBs
and integrated with functional data path elements of this MIB. For
example, new Action functional data path element can be defined for
Traffic Engineering and be integrated with Differentiated Services
functional data path elements, possibly used within the same data
path sharing the same classifiers and meters.
It is more likely that new parameterization tables will be created in
other MIBs as new methods or proprietary methods get deployed for
existing Differentiated Services Functional Data Path Elements. For
example, different kinds of filters can be defined by using new
filter parameterization tables. New scheduling methods can be
deployed by defining new scheduling method OIDs and new scheduling
parameter tables.
Notice both new data path linkage tables and parameterization tables
can be added without needing to change this MIB document or affect
existing tables and their usage.
6. MIB Definition
DIFFSERV-DSCP-TC DEFINITIONS ::= BEGIN
IMPORTS
Integer32, MODULE-IDENTITY, mib-2
FROM SNMPv2-SMI
TEXTUAL-CONVENTION
FROM SNMPv2-TC;
diffServDSCPTC MODULE-IDENTITY
LAST-UPDATED "200205090000Z"
ORGANIZATION "IETF Differentiated Services WG"
CONTACT-INFO
" Fred Baker
Cisco Systems
1121 Via Del Rey
Santa Barbara, CA 93117, USA
E-mail: fred@cisco.com
Kwok Ho Chan
Nortel Networks
600 Technology Park Drive
Billerica, MA 01821, USA
E-mail: khchan@nortelnetworks.com
Andrew Smith
Harbour Networks
Jiuling Building
21 North Xisanhuan Ave.
Beijing, 100089, PRC
E-mail: ah_smith@acm.org
Differentiated Services Working Group:
diffserv@ietf.org"
DESCRIPTION
"The Textual Conventions defined in this module should be used
whenever a Differentiated Services Code Point is used in a MIB."
REVISION "200205090000Z"
DESCRIPTION
"Initial version, published as RFC3289."
::= { mib-2 96 }
Dscp ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"A Differentiated Services Code-Point that may be used for
marking a traffic stream."
REFERENCE
"RFC2474, RFC2780"
SYNTAX Integer32 (0..63)
DscpOrAny ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"The IP header Differentiated Services Code-Point that may be
used for discriminating among traffic streams. The value -1 is
used to indicate a wild card i.e. any value."
REFERENCE
"RFC2474, RFC2780"
SYNTAX Integer32 (-1 | 0..63)
END
DIFFSERV-MIB DEFINITIONS ::= BEGIN
IMPORTS
Unsigned32, Counter64, MODULE-IDENTITY, OBJECT-TYPE,
OBJECT-IDENTITY, zeroDotZero, mib-2
FROM SNMPv2-SMI
TEXTUAL-CONVENTION, RowStatus, RowPointer,
StorageType, AutonomousType
FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP
FROM SNMPv2-CONF
ifIndex, InterfaceIndexOrZero
FROM IF-MIB
InetAddressType, InetAddress, InetAddressPrefixLength,
InetPortNumber
FROM INET-ADDRESS-MIB
BurstSize
FROM INTEGRATED-SERVICES-MIB
Dscp, DscpOrAny
FROM DIFFSERV-DSCP-TC;
diffServMib MODULE-IDENTITY
LAST-UPDATED "200202070000Z"
ORGANIZATION "IETF Differentiated Services WG"
CONTACT-INFO
" Fred Baker
Cisco Systems
1121 Via Del Rey
Santa Barbara, CA 93117, USA
E-mail: fred@cisco.com
Kwok Ho Chan
Nortel Networks
600 Technology Park Drive
Billerica, MA 01821, USA
E-mail: khchan@nortelnetworks.com
Andrew Smith
Harbour Networks
Jiuling Building
21 North Xisanhuan Ave.
Beijing, 100089, PRC
E-mail: ah_smith@acm.org
Differentiated Services Working Group:
diffserv@ietf.org"
DESCRIPTION
"This MIB defines the objects necessary to manage a device that
uses the Differentiated Services Architecture described in RFC
2475. The Conceptual Model of a Differentiated Services Router
provides supporting information on how such a router is modeled."
REVISION "200202070000Z"
DESCRIPTION
"Initial version, published as RFC3289."
::= { mib-2 97 }
diffServMIBObjects OBJECT IDENTIFIER ::= { diffServMib 1 }
diffServMIBConformance OBJECT IDENTIFIER ::= { diffServMib 2 }
diffServMIBAdmin OBJECT IDENTIFIER ::= { diffServMib 3 }
IndexInteger ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"An integer which may be used as a table index."
SYNTAX Unsigned32 (1..4294967295)
IndexIntegerNextFree ::= TEXTUAL-CONVENTION
DISPLAY-HINT "d"
STATUS current
DESCRIPTION
"An integer which may be used as a new Index in a table.
The special value of 0 indicates that no more new entries can be
created in the relevant table.
When a MIB is used for configuration, an object with this SYNTAX
always contains a legal value (if non-zero) for an index that is
not currently used in the relevant table. The Command Generator
(Network Management Application) reads this variable and uses the
(non-zero) value read when creating a new row with an SNMP SET.
When the SET is performed, the Command Responder (agent) must
determine whether the value is indeed still unused; Two Network
Management Applications may attempt to create a row
(configuration entry) simultaneously and use the same value. If
it is currently unused, the SET succeeds and the Command
Responder (agent) changes the value of this object, according to
an implementation-specific algorithm. If the value is in use,
however, the SET fails. The Network Management Application must
then re-read this variable to obtain a new usable value.
An OBJECT-TYPE definition using this SYNTAX MUST specify the
relevant table for which the object is providing this
functionality."
SYNTAX Unsigned32 (0..4294967295)
IfDirection ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"IfDirection specifies a direction of data travel on an
interface. 'inbound' traffic is operated on during reception from
the interface, while 'outbound' traffic is operated on prior to
transmission on the interface."
SYNTAX INTEGER {
inbound(1), -- ingress interface
outbound(2) -- egress interface
}
--
-- Data Path
--
diffServDataPath OBJECT IDENTIFIER ::= { diffServMIBObjects 1 }
--
-- Data Path Table
--
-- The Data Path Table enumerates the Differentiated Services
-- Functional Data Paths within this device. Each entry in this table
-- is indexed by ifIndex and ifDirection. Each entry provides the
-- first Differentiated Services Functional Data Path Element to
-- process data flowing along specific data path. This table should
-- have at most two entries for each interface capable of
-- Differentiated Services processing on this device: ingress and
-- egress.
-- Note that Differentiated Services Functional Data Path Elements
-- linked together using their individual next pointers and anchored by
-- an entry of the diffServDataPathTable constitute a functional data
-- path.
--
diffServDataPathTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServDataPathEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The data path table contains RowPointers indicating the start of
the functional data path for each interface and traffic direction
in this device. These may merge, or be separated into parallel
data paths."
::= { diffServDataPath 1 }
diffServDataPathEntry OBJECT-TYPE
SYNTAX DiffServDataPathEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the data path table indicates the start of a single
Differentiated Services Functional Data Path in this device.
These are associated with individual interfaces, logical or
physical, and therefore are instantiated by ifIndex. Therefore,
the interface index must have been assigned, according to the
procedures applicable to that, before it can be meaningfully
used. Generally, this means that the interface must exist.
When diffServDataPathStorage is of type nonVolatile, however,
this may reflect the configuration for an interface whose ifIndex
has been assigned but for which the supporting implementation is
not currently present."
INDEX { ifIndex, diffServDataPathIfDirection }
::= { diffServDataPathTable 1 }
DiffServDataPathEntry ::= SEQUENCE {
diffServDataPathIfDirection IfDirection,
diffServDataPathStart RowPointer,
diffServDataPathStorage StorageType,
diffServDataPathStatus RowStatus
}
diffServDataPathIfDirection OBJECT-TYPE
SYNTAX IfDirection
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"IfDirection specifies whether the reception or transmission path
for this interface is in view."
::= { diffServDataPathEntry 1 }
diffServDataPathStart OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This selects the first Differentiated Services Functional Data
Path Element to handle traffic for this data path. This
RowPointer should point to an instance of one of:
diffServClfrEntry
diffServMeterEntry
diffServActionEntry
diffServAlgDropEntry
diffServQEntry
A value of zeroDotZero in this attribute indicates that no
Differentiated Services treatment is performed on traffic of this
data path. A pointer with the value zeroDotZero normally
terminates a functional data path.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the treatment is as if this
attribute contains a value of zeroDotZero."
::= { diffServDataPathEntry 2 }
diffServDataPathStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServDataPathEntry 3 }
diffServDataPathStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time."
::= { diffServDataPathEntry 4 }
--
-- Classifiers
--
diffServClassifier OBJECT IDENTIFIER ::= { diffServMIBObjects 2 }
--
-- Classifier Table
--
-- The Classifier Table allows multiple classifier elements, of same or
-- different types, to be used together. A classifier must completely
-- classify all packets presented to it. This means that all traffic
-- presented to a classifier must match at least one classifier element
-- within the classifier, with the classifier element parameters
-- specified by a filter.
-- If there is ambiguity between classifier elements of different
-- classifier, classifier linkage order indicates their precedence; the
-- first classifier in the link is applied to the traffic first.
-- Entries in the classifier element table serves as the anchor for
-- each classification pattern, defined in filter table entries. Each
-- classifier element table entry also specifies the subsequent
-- downstream Differentiated Services Functional Data Path Element when
-- the classification pattern is satisfied. Each entry in the
-- classifier element table describes one branch of the fan-out
-- characteristic of a classifier indicated in the Informal
-- Differentiated Services Model section 4.1. A classifier is composed
-- of one or more classifier elements.
diffServClfrNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for diffServClfrId, or a
zero to indicate that none exist."
::= { diffServClassifier 1 }
diffServClfrTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServClfrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"This table enumerates all the diffserv classifier functional
data path elements of this device. The actual classification
definitions are defined in diffServClfrElementTable entries
belonging to each classifier.
An entry in this table, pointed to by a RowPointer specifying an
instance of diffServClfrStatus, is frequently used as the name
for a set of classifier elements, which all use the index
diffServClfrId. Per the semantics of the classifier element
table, these entries constitute one or more unordered sets of
tests which may be simultaneously applied to a message to
classify it.
The primary function of this table is to ensure that the value of
diffServClfrId is unique before attempting to use it in creating
a diffServClfrElementEntry. Therefore, the diffServClfrEntry must
be created on the same SET as the diffServClfrElementEntry, or
before the diffServClfrElementEntry is created."
::= { diffServClassifier 2 }
diffServClfrEntry OBJECT-TYPE
SYNTAX DiffServClfrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the classifier table describes a single classifier.
All classifier elements belonging to the same classifier use the
classifier's diffServClfrId as part of their index."
INDEX { diffServClfrId }
::= { diffServClfrTable 1 }
DiffServClfrEntry ::= SEQUENCE {
diffServClfrId IndexInteger,
diffServClfrStorage StorageType,
diffServClfrStatus RowStatus
}
diffServClfrId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the classifier entries. Managers
should obtain new values for row creation in this table by
reading diffServClfrNextFree."
::= { diffServClfrEntry 1 }
diffServClfrStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServClfrEntry 2 }
diffServClfrStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time. Setting this variable to
'destroy' when the MIB contains one or more RowPointers pointing
to it results in destruction being delayed until the row is no
longer used."
::= { diffServClfrEntry 3 }
--
-- Classifier Element Table
--
diffServClfrElementNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for diffServClfrElementId,
or a zero to indicate that none exist."
::= { diffServClassifier 3 }
diffServClfrElementTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServClfrElementEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"The classifier element table enumerates the relationship between
classification patterns and subsequent downstream Differentiated
Services Functional Data Path elements.
diffServClfrElementSpecific points to a filter that specifies the
classification parameters. A classifier may use filter tables of
different types together.
One example of a filter table defined in this MIB is
diffServMultiFieldClfrTable, for IP Multi-Field Classifiers
(MFCs). Such an entry might identify anything from a single
micro-flow (an identifiable sub-session packet stream directed
from one sending transport to the receiving transport or
transports), or aggregates of those such as the traffic from a
host, traffic for an application, or traffic between two hosts
using an application and a given DSCP. The standard Behavior
Aggregate used in the Differentiated Services Architecture is
encoded as a degenerate case of such an aggregate - the traffic
using a particular DSCP value.
Filter tables for other filter types may be defined elsewhere."
::= { diffServClassifier 4 }
diffServClfrElementEntry OBJECT-TYPE
SYNTAX DiffServClfrElementEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An entry in the classifier element table describes a single
element of the classifier."
INDEX { diffServClfrId, diffServClfrElementId }
::= { diffServClfrElementTable 1 }
DiffServClfrElementEntry ::= SEQUENCE {
diffServClfrElementId IndexInteger,
diffServClfrElementPrecedence Unsigned32,
diffServClfrElementNext RowPointer,
diffServClfrElementSpecific RowPointer,
diffServClfrElementStorage StorageType,
diffServClfrElementStatus RowStatus
}
diffServClfrElementId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the Classifier Element entries.
Managers obtain new values for row creation in this table by
reading diffServClfrElementNextFree."
::= { diffServClfrElementEntry 1 }
diffServClfrElementPrecedence OBJECT-TYPE
SYNTAX Unsigned32 (1..4294967295)
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The relative order in which classifier elements are applied:
higher numbers represent classifier element with higher
precedence. Classifier elements with the same order must be
unambiguous i.e. they must define non-overlapping patterns, and
are considered to be applied simultaneously to the traffic
stream. Classifier elements with different order may overlap in
their filters: the classifier element with the highest order
that matches is taken.
On a given interface, there must be a complete classifier in
place at all times in the ingress direction. This means one or
more filters must match any possible pattern. There is no such
requirement in the egress direction."
::= { diffServClfrElementEntry 2 }
diffServClfrElementNext OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"This attribute provides one branch of the fan-out functionality
of a classifier described in the Informal Differentiated Services
Model section 4.1.
This selects the next Differentiated Services Functional Data
Path Element to handle traffic for this data path. This
RowPointer should point to an instance of one of:
diffServClfrEntry
diffServMeterEntry
diffServActionEntry
diffServAlgDropEntry
diffServQEntry
A value of zeroDotZero in this attribute indicates no further
Differentiated Services treatment is performed on traffic of this
data path. The use of zeroDotZero is the normal usage for the
last functional data path element of the current data path.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the treatment is as if this
attribute contains a value of zeroDotZero."
::= { diffServClfrElementEntry 3 }
diffServClfrElementSpecific OBJECT-TYPE
SYNTAX RowPointer
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"A pointer to a valid entry in another table, filter table, that
describes the applicable classification parameters, e.g. an entry
in diffServMultiFieldClfrTable.
The value zeroDotZero is interpreted to match anything not
matched by another classifier element - only one such entry may
exist for each classifier.
Setting this to point to a target that does not exist results in
an inconsistentValue error. If the row pointed to is removed or
becomes inactive by other means, the element is ignored."
::= { diffServClfrElementEntry 4 }
diffServClfrElementStorage OBJECT-TYPE
SYNTAX StorageType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The storage type for this conceptual row. Conceptual rows
having the value 'permanent' need not allow write-access to any
columnar objects in the row."
DEFVAL { nonVolatile }
::= { diffServClfrElementEntry 5 }
diffServClfrElementStatus OBJECT-TYPE
SYNTAX RowStatus
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The status of this conceptual row. All writable objects in this
row may be modified at any time. Setting this variable to
'destroy' when the MIB contains one or more RowPointers pointing
to it results in destruction being delayed until the row is no
longer used."
::= { diffServClfrElementEntry 6 }
--
-- IP Multi-field Classification Table
--
-- Classification based on six different fields in the IP header.
-- Functional Data Paths may share definitions by using the same entry.
--
diffServMultiFieldClfrNextFree OBJECT-TYPE
SYNTAX IndexIntegerNextFree
MAX-ACCESS read-only
STATUS current
DESCRIPTION
"This object contains an unused value for
diffServMultiFieldClfrId, or a zero to indicate that none exist."
::= { diffServClassifier 5 }
diffServMultiFieldClfrTable OBJECT-TYPE
SYNTAX SEQUENCE OF DiffServMultiFieldClfrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"A table of IP Multi-field Classifier filter entries that a
system may use to identify IP traffic."
::= { diffServClassifier 6 }
diffServMultiFieldClfrEntry OBJECT-TYPE
SYNTAX DiffServMultiFieldClfrEntry
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An IP Multi-field Classifier entry describes a single filter."
INDEX { diffServMultiFieldClfrId }
::= { diffServMultiFieldClfrTable 1 }
DiffServMultiFieldClfrEntry ::= SEQUENCE {
diffServMultiFieldClfrId IndexInteger,
diffServMultiFieldClfrAddrType InetAddressType,
diffServMultiFieldClfrDstAddr InetAddress,
diffServMultiFieldClfrDstPrefixLength InetAddressPrefixLength,
diffServMultiFieldClfrSrcAddr InetAddress,
diffServMultiFieldClfrSrcPrefixLength InetAddressPrefixLength,
diffServMultiFieldClfrDscp DscpOrAny,
diffServMultiFieldClfrFlowId Unsigned32,
diffServMultiFieldClfrProtocol Unsigned32,
diffServMultiFieldClfrDstL4PortMin InetPortNumber,
diffServMultiFieldClfrDstL4PortMax InetPortNumber,
diffServMultiFieldClfrSrcL4PortMin InetPortNumber,
diffServMultiFieldClfrSrcL4PortMax InetPortNumber,
diffServMultiFieldClfrStorage StorageType,
diffServMultiFieldClfrStatus RowStatus
}
diffServMultiFieldClfrId OBJECT-TYPE
SYNTAX IndexInteger
MAX-ACCESS not-accessible
STATUS current
DESCRIPTION
"An index that enumerates the MultiField Classifier filter
entries. Managers obtain new values for row creation in this
table by reading diffServMultiFieldClfrNextFree."
::= { diffServMultiFieldClfrEntry 1 }
diffServMultiFieldClfrAddrType OBJECT-TYPE
SYNTAX InetAddressType
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The type of IP address used by this classifier entry. While
other types of addresses are defined in the InetAddressType
textual convention, and DNS names, a classifier can only look at
packets on the wire. Therefore, this object is limited to IPv4
and IPv6 addresses."
::= { diffServMultiFieldClfrEntry 2 }
diffServMultiFieldClfrDstAddr OBJECT-TYPE
SYNTAX InetAddress
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The IP address to match against the packet's destination IP
address. This may not be a DNS name, but may be an IPv4 or IPv6
prefix. diffServMultiFieldClfrDstPrefixLength indicates the
number of bits that are relevant."
::= { diffServMultiFieldClfrEntry 3 }
diffServMultiFieldClfrDstPrefixLength OBJECT-TYPE
SYNTAX InetAddressPrefixLength
UNITS "bits"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The length of the CIDR Prefix carried in
diffServMultiFieldClfrDstAddr. In IPv4 addresses, a length of 0
indicates a match of any address; a length of 32 indicates a
match of a single host address, and a length between 0 and 32
indicates the use of a CIDR Prefix. IPv6 is similar, except that
prefix lengths range from 0..128."
DEFVAL { 0 }
::= { diffServMultiFieldClfrEntry 4 }
diffServMultiFieldClfrSrcAddr OBJECT-TYPE
SYNTAX InetAddress
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The IP address to match against the packet's source IP address.
This may not be a DNS name, but may be an IPv4 or IPv6 prefix.
diffServMultiFieldClfrSrcPrefixLength indicates the number of
bits that are relevant."
::= { diffServMultiFieldClfrEntry 5 }
diffServMultiFieldClfrSrcPrefixLength OBJECT-TYPE
SYNTAX InetAddressPrefixLength
UNITS "bits"
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The length of the CIDR Prefix carried in
diffServMultiFieldClfrSrcAddr. In IPv4 addresses, a length of 0
indicates a match of any address; a length of 32 indicates a
match of a single host address, and a length between 0 and 32
indicates the use of a CIDR Prefix. IPv6 is similar, except that
prefix lengths range from 0..128."
DEFVAL { 0 }
::= { diffServMultiFieldClfrEntry 6 }
diffServMultiFieldClfrDscp OBJECT-TYPE
SYNTAX DscpOrAny
MAX-ACCESS read-create
STATUS current
DESCRIPTION
"The value that the DSCP in the packet must have to match this