Request for Comments: 3202 Paradyne Networks
Category: Standards Track O. Nicklass
RAD Data Communications Ltd.
January 2002
Definitions of Managed Objects
for Frame Relay Service Level Definitions
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2002). All Rights Reserved.
Abstract
This memo defines an extension of the Management Information Base
(MIB) for use with network management protocols in TCP/IP-based
internets. In particular, it defines objects for managing the Frame
Relay Service Level Definitions.
Table of Contents
1. The SNMP Management Framework ............................... 2
2. Conventions ................................................. 3
3. Overview .................................................... 3
3.1. Frame Relay Service Level Definitions ..................... 4
3.2. Terminology ............................................... 5
3.3. Network Model ............................................. 5
3.4. Reference Points .......................................... 6
3.5. Measurement Methodology ................................... 8
3.6. Theory of Operation ....................................... 9
3.6.1. Capabilities Discovery .................................. 9
3.6.2. Determining Reference Points for Row Creation ........... 10
3.6.2.1. Graphical Examples of Reference Points ................ 11
3.6.2.1.1. Edge-to-Edge Interface Reference Point Example ...... 12
3.6.2.1.2. Edge-to-Edge Egress Queue Reference Point Example ... 13
3.6.2.1.3. End-to-End Using Reference Point Example ............ 14
3.6.3. Creation Process ........................................ 15
3.6.4. Destruction Process ..................................... 15
3.6.4.1. Manual Row Destruction ................................ 15
3.6.4.2. Automatic Row Destruction ............................. 16
3.6.5. Modification Process .................................... 16
3.6.6. Collection Process ...................................... 16
3.6.6.1. Remote Polling ........................................ 16
3.6.6.2. Sampling .............................................. 17
3.6.6.3. User History .......................................... 17
3.6.7. Use of MIB Module in Calculation of Service Level
Definitions .................................................... 17
3.6.8. Delay ................................................... 20
3.6.9. Frame Delivery Ratio .................................... 20
3.6.10. Data Delivery Ratio .................................... 21
3.6.11. Service Availability ................................... 21
4. Relation to Other MIB Modules ............................... 22
5. Structure of the MIB Module ................................. 23
5.1. frsldPvcCtrlTable ......................................... 23
5.2. frsldSmplCtrlTable ........................................ 23
5.3. frsldPvcDataTable ......................................... 23
5.4. frsldPvcSampleTable ....................................... 24
5.5. frsldCapabilities ......................................... 24
6. Persistence of Data ......................................... 24
7. Object Definitions .......................................... 24
8. Acknowledgments ............................................. 61
9. References .................................................. 61
10. Security Considerations .................................... 63
11. Authors' Addresses ......................................... 63
12. Full Copyright Statement ................................... 64
1. The SNMP Management Framework
The SNMP Management Framework presently consists of five major
components:
o An overall architecture, described in RFC2571 [1].
o Mechanisms for describing and naming objects and events for the
purpose of management. The first version of this Structure of
Management Information (SMI) is called SMIv1 and described in STD
16, RFC1155 [2], STD 16, RFC1212 [3] and RFC1215 [4]. The
second version, called SMIv2, is described in STD 58, RFC2578
[5], RFC2579 [6] and RFC2580 [7].
o Message protocols for transferring management information. The
first version of the SNMP message protocol is called SNMPv1 and
described in STD 15, RFC1157 [8]. A second version of the SNMP
message protocol, which is not an Internet standards track
protocol, is called SNMPv2c and described in RFC1901 [9] and RFC
1906 [10]. The third version of the message protocol is called
SNMPv3 and described in RFC1906 [10], RFC2572 [11] and RFC2574
[12].
o Protocol operations for accessing management information. The
first set of protocol operations and associated PDU formats is
described in STD 15, RFC1157 [8]. A second set of protocol
operations and associated PDU formats is described in RFC1905
[13].
o A set of fundamental applications described in RFC2573 [14] and
the view-based access control mechanism described in RFC2575
[15].
A more detailed introduction to the current SNMP Management Framework
can be found in RFC2570 [16].
Managed objects are accessed via a virtual information store, termed
the Management Information Base or MIB. Objects in the MIB are
defined using the mechanisms defined in the SMI.
This memo specifies a MIB module that is compliant to the SMIv2. A
MIB conforming to the SMIv1 can be produced through the appropriate
translations. The resulting translated MIB must be semantically
equivalent, except where objects or events are omitted because no
translation is possible (use of Counter64). Some machine readable
information in SMIv2 will be converted into textual descriptions in
SMIv1 during the translation process. However, this loss of machine
readable information is not considered to change the semantics of the
MIB.
2. Conventions
The keywords MUST, MUST NOT, REQUIRED, SHALL, SHALL NOT, SHOULD,
SHOULD NOT, RECOMMENDED, NOT RECOMMENDED, MAY, and OPTIONAL, when
they appear in this document, are to be interpreted as described in
RFC2119 [22].
3. Overview
This MIB module addresses the items required to manage the Frame
Relay Forum's Implementation Agreement for Service Level Definitions
(FRF.13 [17]). At present, this applies to these values of the
ifType variable in the Internet-standard MIB:
o frameRelay (32)
o frameRelayService (44)
This section provides an overview and background of how to use this
MIB module.
3.1. Frame Relay Service Level Definitions
The frame relay service level definitions address specific
characteristics of a frame relay service that can be used to
facilitate the following tasks:
o Evaluation of frame relay service providers, offerings or
products.
o Measurement of Quality of Service.
o Enforcement of Service Level Agreements.
o Planning or describing a frame relay network.
The following parameters are defined in FRF.13 [17] as a sufficient
set of values to accomplish the tasks previously stated.
o Delay - The amount of time elapsed, in microseconds, from the time
a frame exits the source to the time it reaches the destination.
NOTE: FRF.13 [17] defines this value in terms of milliseconds.
o Frame Delivery Ratio - The ratio of the number of frames delivered
to the destination versus the number of frames sent by the source.
This ratio can be further divided by inspecting either only the
frames within the CIR or only the frames in excess of the CIR.
o Data Delivery Ratio - The ratio of the amount of data delivered to
the destination versus the amount of data sent by the source.
This ratio can be further divided by inspecting either only the
data within the CIR or only the data in excess of the CIR.
o Service Availability - The amount of time the frame relay service
was not available. There are three types of availability
statistics defined in FRF.13 [17]: Mean Time to Repair, Virtual
Connection Availability, and Mean Time Between Service Outages.
The later two require information about the scheduled outage time.
It is assumed that scheduled outage time information will be
maintained by the network management software, so it is not
included in the MIB module.
Consult FRF.13 [17] for more details.
3.2. Terminology
o CIR - The Committed Information Rate (CIR) is the subscriber data
rate (expressed in bits/second) that the network commits to
deliver under normal network conditions [18].
o DLCI - Data Link Connection Identifier [18].
o Logical Port - This term is used to model the Frame Relay
"interface" on a device [18].
o NNI - Network to Network Interface [18].
o Permanent Virtual Connection (PVC) - A virtual connection that has
its end-points and bearer capabilities defined at subscription
time [18].
o Reference Point (RP) - The point of reference within the network
model at which the calculations or data collection takes place.
o UNI - User to Network Interface [18].
3.3. Network Model
The basic model, as illustrated in figure 1 below, contains two frame
relay DTE endpoints connected to a network cloud via a frame relay
UNI interface. The network cloud can contain zero or more internal
frame relay NNI connections that interconnect multiple networks. The
calculations and data collection can be performed at any reference
point within the network.
+-------------+ +-------------+
| Frame Relay | | Frame Relay |
| DTE Device | | DTE Device |
+------+------+ +------+------+
| |
UNI UNI
Connection Connection
| |
+------+------+ NNI +-------------+ NNI +------+------+
| Network A +------------+ Network B +------------+ Network C |
+-------------+ Connection +-------------+ Connection +-------------+
Figure 1
Frame Relay Network Reference Model
3.4. Reference Points
The collection and calculations of the service level definitions
apply to two reference points within the network. These two points
are the locations where the frames are referenced in the collection
of the service level specific information. The reference points used
in the MIB module are shown in figure 2 below. For completeness, the
module also allows for proprietary reference points which MAY exist
anywhere in the network that is not a previously defined reference
point. The meaning of the proprietary reference points is
insignificant unless defined by the device manufacturer.
+---------------------------+
|+-----------+ +-----------+|
|| | |Measurement||
||Frame Relay---Engine --(Source RP)----+
||DTE | |(If Exists)|| |
|+-----------+ +-----------+| |
+---------------------------+ |
Frame Relay Source |
+------------------------------------------+
| Frame Relay Network
| +----------------------------------+
| | +------------------------------+ |
| | | +---------+ +---------+ | |
| | | | | | Traffic | | |
+--(Ingress RP)--- L1 / L2 --- Policing| | |
| | | Control | | Engine | | |
| | +---------+ +----|----+ | |
| | | | |
| | (Traffic Policing RP)| |
| +------------------|-----------+ |
| Ingress Node | |
| | |
| +-----------|-----------+ |
| | Intermediate Nodes | |
| +-----------|-----------+ |
| | |
| Egress Node | |
| +--------------|-----------+ |
| | (Egress Queue Input RP) | |
| | | | |
| | +-------+------+ | |
| | | Egress Queue | | |
| | +-------+------+ | |
| | | | |
| | (Egress Queue Output RP) | |
| +--------------|-----------+ |
+--------------------|-------------+
Frame Relay Destination |
+---------------------------+ +-----------+
|+-----------+ +-----------+| |
|| | |Measurement|| |
||Frame Relay---Engine --(Destination RP)--+
||DTE | |(If Exists)||
|+-----------+ +-----------+|
+---------------------------+
Figure 2
Reference Points (FRF.13 [17])
The MIB variables frsldPvcCtrlTransmitRP and frsldPvcCtrlReceiveRP
allow the user to view and configure the reference points at which
the calculations occur. These variables are specific to the device
on which they are located. Frame relay devices act as both frame
sources and frame destinations. The definitions in this MIB module
apply to the interaction of a pair of devices on the network path.
The same device can potentially use different reference points for
calculation and collection of the statistics based on whether the
referenced frame is sent or received by the device. When the device
is acting as a frame source, the value of frsldPvcCtrlTransmitRP
reflects the reference point used for all source calculations
pertaining to the specified PVC. When the device is acting as a
frame destination, the value of frsldPvcCtrlReceiveRP reflects the
reference point used for all destination calculations pertaining to
the specified PVC.
For example, FRF.13 [17] defines an Edge-to-Edge Egress Queue
measurement domain as a domain in which measurement is performed
between an Ingress Reference Point and an Egress Queue Input
Reference Point. For this domain between a source device and a
destination device, the value of frsldPvcCtrlTransmitRP for the
source device would be set to ingTxLocalRP(2) and the value of
frsldPvcCtrlReceiveRP for the destination device would be set to
eqiRxLocalRP(4). While it is usually the case that the reference
points would be equivalent on the remote device when monitoring
frames going in the opposite direction, there is no requirement for
them to be so.
It can be seen from the above example that a total of four reference
points are required in order to collect information for both
directions of traffic flow. The reference points represent the
transmit and receive directions at both ends of a PVC. If a device
has knowledge of the information from the remote device, it is
possible to collect the statistics from a single device. This is not
always the case. In most instances, two devices will need to be
monitored to capture a complete description of the service level on a
PVC. The reference points a single device is capable of monitoring
are contained in the frsldRPCaps object.
3.5. Measurement Methodology
This document neither recommends nor suggests a method of
implementation. This is left to the device manufacturer and should
be independent of the data that is actually collected.
Periodic collection of this data can be performed through either
polling of the data table, use of the sample tables or use of the
user history group of RFC2021 [19].
3.6. Theory of Operation
The following sections describe how to use this MIB module. They
include row handling, data collection and data calculation. The
recommendations here in are suggestions as to implementation and do
not infer that they are the only method that can be used to perform
such operations.
3.6.1. Capabilities Discovery
Three objects are provided specifically to aid the network manager in
discovering the capabilities of the device with respect to this MIB
module.
o frsldPvcCtrlWriteCaps This object reports the write capabilities
of the PVC Control Table. Use this object
to determine which objects can be modified.
This need only be referenced if row
creation or modification is to be
performed.
o frsldSmplCtrlWriteCaps This object reports the write capabilities
of the Sample Control Table. Use this
object to determine which objects can be
modified. The group need only be
referenced if the sample tables will be
used to collect historical information.
o frsldRPCaps This object reports the reference points at
which the device is capable of collecting
information. This object needs to be
referenced if row creation is to be
performed in the PVC Control Table.
Devices can only create rows containing
supported reference points.
These objects do not imply that there is no need for an Agent
Capabilities macro for devices that do not fully support every object
in this MIB module. They are provided specifically to aid in the
ensured network management operations of this MIB module with respect
to row creation and modification.
An additional four objects are provided to report and control memory
the utilization of this MIB module. These objects are
frsldMaxPvcCtrls, frsldNumPvcCtrls, frsldMaxSmplCtrls are
frsldNumSmplCtrls. Together, they allow a manager to control the
amount of memory allocated for specific utilization by this MIB
module. This is done by setting the maximum allowed allocation of
controls.
3.6.2. Determining Reference Points for Row Creation
The performance of a PVC is monitored by evaluating the uni-
directional flow of frames from an ingress point to an egress point.
Reference points describe where each of the two measurements are
made. Monitoring both of the uni-directional flows that make-up the
PVC frame traffic requires a total of four reference points as shown
in Figures 3 through 5. A monitoring point that evaluates traffic is
restricted to counting frames that pass the reference points hosted
locally on the monitoring point. Thus, if the monitoring point is
near the ingress point of the flow, it will count the frames entering
into the frame relay network. The complete picture of frame loss for
the uni-directional flow requires information from the downstream
reference point located at another (remote) monitoring point.
The local monitoring point MAY be implemented in such way that the
information from the downstream monitoring point is moved to the
local monitoring point using implementation-specific mechanisms. In
this case all information required to calculate frame loss becomes
available from the local measurement point. The local measurement
point agent is capable of reporting all the objects in the
FrsldPvcDataEntry row - the counts for offered frames entering the
network and delivered frames exiting the network.
Alternatively, the local monitoring point MAY be restricted to counts
of frames observed on the local device only. In this case, the
objects of the FrsldPvcDataEntry row reporting what happened on the
remote device are not available.
The following list shows the possible valid reference points for an
FRF.13 SLA from the source reference point to the destination
reference point in both directions.
o Local Information Only
Local Device: srcLocalRP, desLocalRP
Remote Device: srcLocalRP, desLocalRP
o Remote Information Only
Local Device: srcRemoteRP, desRemoteRP
Remote Device: srcRemoteRP, desRemoteRP
o Mixed Two Device Model 1 (Local Device Always Transmitter)
Local Device: srcLocalRP, desRemoteRP
Remote Device: srcLocalRP, desRemoteRP
o Mixed Two Device Model 2 (Local Device Always Receiver)
Local Device: srcRemoteRP, desLocalRP
Remote Device: srcRemoteRP, desLocalRP
o Mixed One Device Model 1 (Directional Rows)
First Row: srcRemoteRP, desLocalRP (Receiver Row)
Second Row: srcLocalRP, desRemoteRP (Sender Row)
o Mixed One Device Model 2 (Device Based Rows)
First Row: srcLocalRP, desLocalRP (Local Row)
Second Row: srcRemoteRP, desRemoteRP (Remote Row)
Each of the above combinations is valid and provides the same
information.
The following steps are recommended to find which reference points
need to be configured:
1) Locate both of the devices at either end of the PVC to be
monitored.
2) Determine the capabilities by referencing the frsldRPCaps object
of each device.
3) Locate the best combination of the two devices such that the
necessary reference points are all represented.
4) If any one of the necessary reference points does not exist in the
combination of the two devices, it is not possible to monitor the
FRF.13 defined SLA between the two reference point on the PVC.
3.6.2.1. Graphical Examples of Reference Points
FRF.13 [17] defines three specific combinations of reference points:
Edge-to-Edge Interface, Edge-to-Edge Egress Queue and End-to-End.
Examples of valid reference points that may be used for each of these
are discussed in the sections below.
It is often the case that a device knows as a minimum either only
local information or both local and remote information. Because
these are two common examples, each will be illustrated below.
3.6.2.1.1. Edge-to-Edge Interface Reference Point Example
Device 1 Device 2
+-------------+ +-------------+
| Ingress | | Egress |
| +-----+ | | +-----+ |
|(A)| | | Traffic Flow | | |(B)|
-->-->-- -->-->-->-->-->-->-->-->-->-->-->- -->-->-->
| | | | From Device 1 to 2 | | | |
| +-----+ | | +-----+ |
| | | |
| Egress | | Ingress |
| +-----+ | | +-----+ |
|(D)| | | Traffic Flow | | |(C)|
<--<--<- -<--<--<--<--<--<--<--<--<--<--<-- --<--<--
| | | | From Device 2 to 1 | | | |
| +-----+ | | +-----+ |
+-------------+ +-------------+
where (A), (B), (C) and (D) are reference points
Figure 3
For devices with only local knowledge, one row is required on each
device as follows:
(A) frsldPvcCtrlTransmitRP for Device 1 = ingTxLocalRP(2)
(B) frsldPvcCtlrReceiveRP for Device 2 = eqoRxLocalRP(5)
(C) frsldPvcCtrlTransmitRP for Device 2 = ingTxLocalRP(2)
(D) frsldPvcCtlrReceiveRP for Device 1 = eqoRxLocalRP(5)
In which a single row is created on Device 1 containing reference
points (A) and (D), and a single row is created on Device 2
containing reference points (C) and (B).
For devices with both local and remote knowledge, the two rows can
exist in any combination on either device. For this example, the
transmitting devices will be responsible for information regarding
the flow for which they are the origin. Only one row is required per
device for this example.
(A) frsldPvcCtrlTransmitRP for Device 1 = ingTxLocalRP(2)
(B) frsldPvcCtlrReceiveRP for Device 1 = eqoRxRemoteRP(11)
(C) frsldPvcCtrlTransmitRP for Device 2 = ingTxLocalRP(2)
(D) frsldPvcCtlrReceiveRP for Device 2 = eqoRxRemoteRP(11)
3.6.2.1.2. Edge-to-Edge Egress Queue Reference Point Example
Device 1 Device 2
+-------------+ +-------------+
| Ingress | | Egress |
| +-----+ | | +-----+ |
|(A)| | | Traffic Flow |(B)| | |
-->-->-- -->-->-->-->-->-->-->-->-->-->-->- -->-->-->
| | | | From Device 1 to 2 | | | |
| +-----+ | | +-----+ |
| | | |
| Egress | | Ingress |
| +-----+ | | +-----+ |
| | |(D)| Traffic Flow | | |(C)|
<--<--<- -<--<--<--<--<--<--<--<--<--<--<-- --<--<--
| | | | From Device 2 to 1 | | | |
| +-----+ | | +-----+ |
+-------------+ +-------------+
where (A), (B), (C) and (D) are reference points
Figure 4
For devices with only local knowledge, one row is required on each
device as follows:
(A) frsldPvcCtrlTransmitRP for Device 1 = ingTxLocalRP(2)
(B) frsldPvcCtlrReceiveRP for Device 2 = eqiRxLocalRP(4)
(C) frsldPvcCtrlTransmitRP for Device 2 = ingTxLocalRP(2)
(D) frsldPvcCtlrReceiveRP for Device 1 = eqiRxLocalRP(4)
In which a single row is created on Device 1 containing reference
points (A) and (D), and a single row is created on Device 2
containing reference points (C) and (B).
For devices with both local and remote knowledge, the two rows can
exist in any combination on either device. For this example, the
transmitting devices will be responsible for information regarding
the flow for which they are the origin. Only one row is required per
device for this example.
(A) frsldPvcCtrlTransmitRP for Device 1 = ingTxLocalRP(2)
(B) frsldPvcCtlrReceiveRP for Device 1 = eqiRxRemoteRP(10)
(C) frsldPvcCtrlTransmitRP for Device 2 = ingTxLocalRP(2)
(D) frsldPvcCtlrReceiveRP for Device 2 = eqiRxRemoteRP(10)
3.6.2.1.3. End-to-End Using Reference Point Example
Device 1 Device 2
+-------------+ +-------------+
| Source | | Destination |
| +-----+ | | +-----+ |
|(A)| | | Traffic Flow | | |(B)|
-->-->-- -->-->-->-->-->-->-->-->-->-->-->- -->-->-->
| | | | From Device 1 to 2 | | | |
| +-----+ | | +-----+ |
| | | |
| Destination | | Source |
| +-----+ | | +-----+ |
|(D)| | | Traffic Flow | | |(C)|
<--<--<- -<--<--<--<--<--<--<--<--<--<--<-- --<--<--
| | | | From Device 2 to 1 | | | |
| +-----+ | | +-----+ |
+-------------+ +-------------+
where (A), (B), (C) and (D) are reference points
Figure 5
For devices with only local knowledge, one row is required on each
device as follows:
(A) frsldPvcCtrlTransmitRP for Device 1 = srcLocalRP(1)
(B) frsldPvcCtlrReceiveRP for Device 2 = desLocalRP(1)
(C) frsldPvcCtrlTransmitRP for Device 2 = srcLocalRP(1)
(D) frsldPvcCtlrReceiveRP for Device 1 = desLocalRP(1)
In which a single row is created on Device 1 containing reference
points (A) and (D), and a single row is created on Device 2
containing reference points (C) and (B).
For devices with both local and remote knowledge, the two rows can
exist in any combination on either device. For this example, the
transmitting devices will be responsible for information regarding
the flow for which they are the origin. Only one row is required per
device for this example.
(A) frsldPvcCtrlTransmitRP for Device 1 = srcLocalRP(1)
(B) frsldPvcCtlrReceiveRP for Device 1 = desRemoteRP(7)
(C) frsldPvcCtrlTransmitRP for Device 2 = srcLocalRP(1)
(D) frsldPvcCtlrReceiveRP for Device 2 = desRemoteRP(7)
3.6.3. Creation Process
In some cases, devices will automatically populate the rows of PVC
Control Table and potentially the Sample Control Table. However, in
many cases, it may be necessary for a network manager to manually
create rows.
Manual creation of rows requires the following steps:
1) Ensure the PVC exists between the two devices.
2) Determine the necessary reference points for row creation.
3) Create the row(s) in each device as needed.
4) Create the row(s) in the sample control tables if desired.
3.6.4. Destruction Process
3.6.4.1. Manual Row Destruction
Manual row destruction is straight forward. Any row can be destroyed
and the resources allocated to it are freed by setting the value of
its status object (either frsldPvcCtrlStatus or frsldSmplCtrlStatus)
to destroy(6). It should be noted that when frsldPvcCtrlStatus is
set to destroy(6) all associated sample control, sample and data
table rows will also be destroyed. Similarly, when
frsldSmplCtrlStatus is set to destroy(6) all sample rows will also be
destroyed. The frsldPvcCtrlPurge objects do not apply to manual row
destruction. If the row is set to destroy(6) manually, the rows are
destroyed as part of the set.
3.6.4.2. Automatic Row Destruction
Rows is the tables may be destroyed automatically based on the
existence of the DLCI on which they rely. This behavior is
controlled by the frsldPvcCtrlPurge and frsldPvcCtrlDeleteOnPurge
objects. When a DLCI no longer exists in the device, the data in the
tables has no relation to anything known on the network. However,
there may be some need to keep the historic information active for a
short period after the destruction or removal of a DLCI. If the
basis for the row no longer exists, the row will be destroyed at the
end of the purge interval that is controlled by frsldPvcCtrlPurge.
The effects of automatic row destruction are the same as manual row
destruction.
3.6.5. Modification Process
All read-create items in this MIB module can be modified at any time
if they are fully supported. Write access is not required. To
simplify the use of the MIB frsldPvcCtrlWriteCaps and
frsldSmplCtrlWriteCaps state which of the read-create variables can
actually be written on a particular device.
3.6.6. Collection Process
3.6.6.1. Remote Polling
This MIB module supports data collection through remote polling of
the free running counters in the PVC Data Table. Remote polling is a
common method used to capture real-time statistics. A remote
management station polls the device to collect the desired
information. It is recommended all statistics for a single PVC be
collected in a single PDU.
The following objects are designed around the concept of real-time
polling:
o frsldPvcDataMissedPolls
o frsldPvcDataFrDeliveredC
o frsldPvcDataFrDeliveredE
o frsldPvcDataFrOfferedC
o frsldPvcDataFrOfferedE
o frsldPvcDataDataDeliveredC
o frsldPvcDataDataDeliveredE
o frsldPvcDataDataOfferedC
o frsldPvcDataDataOfferedE
o frsldPvcDataHCFrDeliveredC
o frsldPvcDataHCFrDeliveredE
o frsldPvcDataHCFrOfferedC
o frsldPvcDataHCFrOfferedE
o frsldPvcDataHCDataDeliveredC
o frsldPvcDataHCDataDeliveredE
o frsldPvcDataHCDataOfferedC
o frsldPvcDataHCDataOfferedE
o frsldPvcDataUnavailableTime
o frsldPvcDataUnavailables
3.6.6.2. Sampling
The sample tables provide the ability to historically sample data
without requiring the additional overhead of polling. At key
periods, a network management station can collect the samples needed.
This method allows the manager to perform the collection of data at
times that will least affect the active network traffic.
The sample data can be collected using a series of SNMP getNext or
getBulk operations. The value of frsldPvcSmplIdx increments with
each new collection bucket. This allows the managers to skip
information that has already been collected. However, care should be
taken in that the value can roll over after a long period of time.
The start and end times of a collection period allow the manager to
know what the actual period of collection was. It is possible for
there to be discontinuities in the sample table, so both start and
end should be referenced.
3.6.6.3. User History
User history, as defined in RFC2021 [19], is an alternative
mechanism that can be used to get the same benefits as the sample
table by using the objects provided for real-time polling. Some
devices MAY have the ability to use user history and opt not to
support the sample tables. If this is the case, the information from
the data table can be used to define a group of user history objects.
3.6.7. Use of MIB Module in Calculation of Service Level Definitions
The objects in this MIB module can be used to calculate the
statistics defined in FRF.13 [17]. The description below describes
the calculations for one direction of the data flow, i.e., data sent
from local transmitter to a remote receiver. A complete set of
bidirectional information would require calculations based on both
directions. For the purposes of this description, the reference
points used SHOULD consistently represent data that is sent by one
device and received by the other.
A complete evaluation requires the combination of two uni-directional
flows. It is possible for a management station to combine all of the
calculated information into one conceptual row. Doing this requires
that each of the metrics are collected for both flow directions and
grouped by direction If the information is split between two
devices, the management station must know which two devices to
communicate with for the collection of all information. The grouping
of information SHOULD be from ingress to egress in each flow
direction.
The calculations below use the following terminology:
o DelayAvg
The average delay on the PVC. This is represented within the
MIB module by frsldPvcSmplDelayAvg.
o FrDeliveredC
The number of frames received by the receiving device through
the receive reference point that were delivered within CIR.
This is represented within the MIB module by one of
frsldPvcDataFrDeliveredC, frsldPvcDataHCFrDeliveredC,
frsldPvcSmplFrDeliveredC, or frsldPvcSmplHCFrDeliveredC.
o FrDeliveredE
The number of frames received by the receiving device through
the receive reference point that were delivered in excess of
CIR. This is represented within the MIB module by one of
frsldPvcDataFrDeliveredE, frsldPvcDataHCFrDeliveredE,
frsldPvcSmplFrDeliveredE, or frsldPvcSmplHCFrDeliveredE.
o FrOfferedC
The number of frames offered by the transmitting device through
the transmit reference point that were sent within CIR. This
is represented within the MIB module by one of
frsldPvcDataFrOfferedC, frsldPvcDataHCFrOfferedC,
frsldPvcSmplFrOfferedC, or frsldPvcSmplHCFrOfferedC.
o FrOfferedE
The number of frames offered by the transmitting device through
the transmit reference point that were sent in excess of CIR.
This is represented within the MIB module by one of
frsldPvcDataFrOfferedE, frsldPvcDataHCFrOfferedE,
frsldPvcSmplFrOfferedE, or frsldPvcSmplHCFrOfferedE.
o DataDeliveredC
The number of octets received by the receiving device through
the receive reference point that were delivered within CIR.
This is represented within the MIB module by one of
frsldPvcDataDataDeliveredC, frsldPvcDataHCDataDeliveredC,
frsldPvcSmplDataDeliveredC, or frsldPvcSmplHCDataDeliveredC.
o DataDeliveredE
The number of octets received by the receiving device through
the receive reference point that were delivered in excess of
CIR. This is represented within the MIB module by one of
frsldPvcDataDataDeliveredE, frsldPvcDataHCDataDeliveredE,
frsldPvcSmplDataDeliveredE, or frsldPvcSmplHCDataDeliveredE.
o DataOfferedC
The number of octets offered by the transmitting device through
the transmit reference point that were sent within CIR. This
is represented within the MIB module by one of
frsldPvcDataDataOfferedC, frsldPvcDataHCDataOfferedC,
frsldPvcSmplDataOfferedC, or frsldPvcSmplHCDataOfferedC.
o DataOfferedE
The number of octets offered by the transmitting device through
the transmit reference point that were sent in excess of CIR.
This is represented within the MIB module by one of
frsldPvcDataDataOfferedE, frsldPvcDataHCDataOfferedE,
frsldPvcSmplDataOfferedE, or frsldPvcSmplHCDataOfferedE.
o UnavailableTime
The amount of time the PVC was not available during the
interval of interest. This is represented within the MIB
module by either frsldPvcDataUnavailableTime or
frsldPvcSmplUnavailableTime.
o Unavailables
The number of times the PVC was declared to be unavailable
during the interval of interest. This is represented within
the MIB module by either frsldPvcDataUnavailables or
frsldPvcSmplUnavailables.
3.6.8. Delay
The frame transfer delay is defined as the amount of time elapsed, in
microseconds, from the time a frame exits the source to the time it
reaches the destination. The average delay can be found using the
MIB variable described in DelayAvg above. The delay may be
calculated as either round trip or one way, and this information is
held in the frsldPvcCtrlDelayType MIB variable. If the delay be
calculated as round trip, the value of DelayAvg represents the
average of the total delays of the round trips. In this case, the
manager SHOULD divide the value returned by the agent by two to
obtain the frame transfer delay. In the case that
frsldPvcCtrlDelayType is oneWay, the value of DelayAvg represents the
average of the frame transfer delays and SHOULD be used as is.
3.6.9. Frame Delivery Ratio
The frame delivery ratio is defined as the total number of frames
delivered to the destination divided by the frames offered by the
source. The destination values can be obtained using FrDeliveredC
and FrDeliveredE. The source values can be obtained using FrOfferedC
and FrOfferedE.
FrDeliveredC + FrDeliveredE
Frame Delivery Ratio = ---------------------------
FrOfferedC + FrOfferedE
FrDeliveredC
Committed Frame Delivery Ratio = ------------
FrOfferedC
FrDeliveredE
Excess Frame Delivery Ratio = ------------
FrOfferedE
3.6.10. Data Delivery Ratio
The data delivery ratio is defined as the total amount of data
delivered to the destination divided by the data offered by the
source. The destination values can be obtained using DataDeliveredC
and DataDeliveredE. The source values can be obtained using
DataOfferedC and DataOfferedE.
DataDeliveredC + DataDeliveredE
Data Delivery Ratio = -------------------------------
DataOfferedC + DataOfferedE
DataDeliveredC
Committed Data Delivery Ratio = --------------
DataOfferedC
DataDeliveredE
Excess Data Delivery Ratio = --------------
DataOfferedE
3.6.11. Service Availability
Some forms of service availability measurement defined in FRF.13 [17]
require knowledge of the amount of time the network is allowed to be
unavailable during the period of measurement. This is called the
excluded outage time and will be represented in the measurements
below as ExcludedTime. It is assumed that the management software
will maintain this information in that it often relates to specific
times and dates that many devices are not capable of maintaining.
Further, it may change based on a moving maintenance window that the
device cannot track well.
Mean Time to Repair (FRMTTR) = 0 if Unavailables is 0.
UnavailableTime
Otherwise, FRMTTR = ---------------
Unavailables
Virtual Connection Availability (FRVCA) = 0 if IntervalTime equals
ExcludedTime.
IntervalTime - ExcludedTime - UnavailableTime
Otherwise, FRVCA = --------------------------------------------- *100
IntervalTime - ExcludedTime
Mean Time Between Service Outages (FRMTBSO) = 0 if Unavailables is 0.
Otherwise, FRMTBSO = IntervalTime - ExcludedTime - UnavailableTime
---------------------------------------------
Unavailables
4. Relation to Other MIB Modules
There is no explicit relation to any other frame relay MIB module nor
are any required to implement this MIB module. However, there is a
need for knowledge of ifIndexes and some understanding of DLCIs. The
ifIndex information can be found in the IF-MIB [21] which is
required. The DLCI information can be found in either the Frame
Relay DTE MIB (RFC2115) [20] or the Frame Relay Network Services MIB
(RFC2954) [18]; however, neither is required.
Upon setting of frsldPvcCtrlStatus in the frsldPvcCtrlTable to
active(1) the system can be in one of the following three states:
(1) The respective DLCI is known and is active. This corresponds to
a state in which frPVCEndptRowStatus is active(1) and
frPVCEndptRcvdSigStatus is either active(2) or none(4) for the
Frame Relay Network Services MIB (RFC2954) [18]. For the Frame
Relay DTE MIB, the same state is shown by frCircuitRowStatus of
active(1) and frCircuitState of active(2).
(2) The respective DLCI has not been created. This corresponds to a
state in which the row with either frPVCEndptDLCIIndex or
frCircuitDlci equal to the respective DLCI does not exist in
either the frPVCEndptTable or the frCircuitTable respectively.
(3) The respective DLCI has just been removed. This corresponds to a
state in which either frPVCEndptRowStatus is no longer active(1)
or frPVCEndptRcvdSigStatus is no longer active(2) or none(4) for
the Frame Relay Network Services MIB (RFC2954) [18]. For the
Frame Relay DTE MIB, the same state is shown when either
frCircuitRowStatus is no longer active(1) or frCircuitState is no
longer active(2).
For the first case, the row in the frsldPvcDataTable will be filled.
If frsldSmplCtrlStatus in the frsldSmplCtrlTable for the respective
DLCI is also `active' the frsldPvcSampleTable will be filled as well.
For the second case, the respective rows will not be added to any of
the data or sample tables and frsldPvcCtrlStatus SHOULD report
notReady(3).
For the third case, frsldPvcCtrlDeleteOnPurge should direct the
behavior of the system. If all tables are purged, this case will be
equivalent to the second case above. Otherwise, frsldPvcCtrlStatus
SHOULD remain active(1).
5. Structure of the MIB Module
The FRSLD-MIB consists of the following components:
o frsldPvcCtrlTable
o frsldSmplCtrlTable
o frsldPvcDataTable
o frsldPvcSampleTable
o frsldCapabilities
Refer to the compliance statement defined within for a definition of
what objects MUST be implemented.
5.1. frsldPvcCtrlTable
The frsldPvcCtrlTable is the central control table for operations of
the Frame Relay Service Level Definitions MIB. It provides variables
to control the parameters required to calculate the objects in the
other tables.
A row in this table MUST exist in order for a row to exist in any
other table in this MIB module.
5.2. frsldSmplCtrlTable
This is an optional table to allow control of sampling of the data in
the data table.
5.3. frsldPvcDataTable
This table contains the calculated data. It relies on configuration
from the control table.
5.4. frsldPvcSampleTable
This table contains samples of the delivery and availability
information from the data table as well as delay information
calculated over the sample period. It relies on configuration from
both the control table and the sample control table.
5.5. frsldCapabilities
This is a group of objects that define write capabilities of the
read-create objects in the tables above.
6. Persistence of Data
The data in frsldPvcCtrlTable and frsldSmplCtrlTable SHOULD persist
through power cycles. Note, however, that the symantics of readiness
for the rows still applies. This means that it is possible for a row
to be reprovisioned as notReady(3) if the underlying DLCI does not
persist. The data collected in the other tables SHOULD NOT persist
through power cycles in that the reference TimeStamp is no longer
valid.
7. Object Definitions
FRSLD-MIB DEFINITIONS ::= BEGIN
IMPORTS
MODULE-IDENTITY, OBJECT-TYPE,
Counter32, Gauge32, Integer32,
Counter64, TimeTicks, mib-2 FROM SNMPv2-SMI
CounterBasedGauge64 FROM HCNUM-TC
TEXTUAL-CONVENTION, RowStatus,
TimeStamp FROM SNMPv2-TC
MODULE-COMPLIANCE, OBJECT-GROUP FROM SNMPv2-CONF
ifIndex FROM IF-MIB
DLCI FROM FRAME-RELAY-DTE-MIB;
frsldMIB MODULE-IDENTITY
LAST-UPDATED "200201030000Z" -- January 3, 2002
ORGANIZATION "IETF Frame Relay Service MIB Working Group"
CONTACT-INFO
"IETF Frame Relay Service MIB (frnetmib) Working Group
WG Charter: http://www.ietf.org/html.charters/
frnetmib-charter.html
WG-email: frnetmib@sunroof.eng.sun.com
Subscribe: frnetmib-request@sunroof.eng.sun.com
Email Archive: ftp://ftp.ietf.org/ietf-mail-archive/frnetmib
Chair: Andy Malis
Vivace Networks
Email: Andy.Malis@vivacenetworks.com
WG editor: Robert Steinberger
Paradyne Networks and
Fujitsu Network Communications
Email: robert.steinberger@fnc.fujitsu.com
Co-author: Orly Nicklass
RAD Data Communications Ltd.
EMail: Orly_n@rad.co.il"
DESCRIPTION
"The MIB module to describe generic objects for
FRF.13 Frame Relay Service Level Definitions."
REVISION "200201030000Z" -- January 3, 2002
DESCRIPTION
"Initial version, published as RFC3202"
::= { mib-2 95 }
--
-- Textual Conventions
--
FrsldTxRP ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"The reference point a PVC uses for calculation
of transmitter related statistics.
The valid values for this type of object are as follows:
- srcLocalRP(1) for the local source
- ingTxLocalRP(2) for the local ingress queue input
- tpTxLocalRP(3) for the local traffic policing
- eqiTxLocalRP(4) for the local egress queue input
- eqoTxLocalRP(5) for the local egress queue output
- otherTxLocalRP(6) for any other local transmit point
- srcRemoteRP(7) for the remote source
- ingTxLocalRP(8) for the remote ingress queue input
- tpTxLocalRP(9) for the remote traffic policing
- eqiTxRemoteRP(10) for the remote egress queue input
- eqoTxRemoteRP(11) for the remote egress queue output
- otherTxRemoteRP(12) for any other remote xmit point"
REFERENCE
"FRF.13: Section 2.3"
SYNTAX INTEGER {
srcLocalRP(1),
ingTxLocalRP(2),
tpTxLocalRP(3),
eqiTxLocalRP(4),
eqoTxLocalRP(5),
otherTxLocalRP(6),
srcRemoteRP(7),
ingTxRemoteRP(8),
tpTxRemoteRP(9),
eqiTxRemoteRP(10),
eqoTxRemoteRP(11),
otherTxRemoteRP(12)
}
FrsldRxRP ::= TEXTUAL-CONVENTION
STATUS current
DESCRIPTION
"The reference point a PVC uses for calculation
of receiver related statistics.
The valid values for this object are as follows:
- desLocalRP(1) for the local destination
- ingRxLocalRP(2) for the local ingress queue input
- tpRxLocalRP(3) for the local traffic policing
- eqiRxLocalRP(4) for the local egress queue input
- eqoRxLocalRP(5) for the local egress queue output
- otherRxLocalRP(6) for any other local receive point
- desRemoteRP(7) for the remote destination
- ingRxRemoteRP(8) for the remote ingress input
- tpRxRemoteRP(9) for the remote traffic policing
- eqiRxRemoteRP(10) for the remote egress queue input
- eqoRxRemoteRP(11) for the remote egress queue output
- otherRxRemoteRP(12) for any other remote receive point"
REFERENCE
"FRF.13: Section 2.3"
SYNTAX INTEGER {
desLocalRP(1),
ingRxLocalRP(2),
tpRxLocalRP(3),
eqiRxLocalRP(4),
eqoRxLocalRP(5),
otherRxLocalRP(6),
desRemoteRP(7),
ingRxRemoteRP(8),