2.4.11 Remote Network Monitoring (rmonmib)

NOTE: This charter is a snapshot of the 47th IETF Meeting in Adelaide, Australia. It may now be out-of-date. Last Modified: 29-Feb-00


Andy Bierman <abierman@cisco.com>

Operations and Management Area Director(s):

Randy Bush <randy@psg.com>
Bert Wijnen <bwijnen@lucent.com>

Operations and Management Area Advisor:

Bert Wijnen <bwijnen@lucent.com>

Technical Advisor(s):

Steven Waldbusser <waldbusser@ins.com>

Mailing Lists:

General Discussion:rmonmib@cisco.com
To Subscribe: rmonmib-request@cisco.com
Archive: ftpeng.cisco.com/ftp/rmonmib/rmonmib

Description of Working Group:

The RMON MIB Working Group is chartered to define a set of managed objects for remote monitoring of networks. These objects will be the minimum necessary to provide the ability to monitor multiple network layers of traffic in remote networks; providing fault, configuration, and performance management, and will be consistent with the SNMP framework and existing SNMP standards.

The following list of features for this RMON has been previously discussed in relation to existing RMON functionality and is included to focus these RMON activities. It is recognized that other issues may be considered and that certain of the following issues may not be part of the final specification(s):

1) Application Performance Measurement Monitoring support for the measurement and characterization of network application protocols, striving to measure an application user's experience as closely as possible. The RMON-2 MIB (RFC 2021) contains a protocol directory that will be used to identify applications for monitoring purposes.

While it is important to measure the performance of computing and network resources, these measurements don't give an insight to the actual service delivered to end-users. This end-user experience is best measured by the response-time and availability of application transactions because users interact directly with applications. This working group will create extensions to the RMON-2 MIB that will allow Application Performance Measurements to be retrieved with SNMP, no matter which technology is used to perform the measurements.

The goal of the working group is to provide a common framework and set of MIB objects, within the current RMON framework, for the identification and characterization of application responsiveness and availability, and the reporting of test results produced by such mechanisms. Common metrics and derived metrics will be characterized and reported in a manner consistent with the IP Performance Metrics Framework (RFC 2330).

It is an explicit non-goal of the working group to select one or more mechanisms as the preferred or standard RMON application performance measurement mechanism. However, it is possible that one or more standard mechanisms will be developed in the future, after significant implementation experience has been gained by the working group.

2) Differentiated Services Statistics Collection Monitoring support for Differentiated Services (DS) statistics collection, for the purpose of DS codepoint usage analysis and possibly other statistics related to DS deployment and performance tuning.

3) Interface TopN Reporting It is often too slow or difficult to determine the busiest ports in devices such as high port-density switches, using existing RMON mechanisms. New monitoring support is needed for quickly determining the most congested (highest utilized) physical ports and links in an RMON-capable device with multiple interfaces.

4) TR-RMON MIB Advancement The Token Ring RMON MIB (RFC 1513) is ready for standards track advancement. An interoperability and deployment survey has already been completed, but the MIB must be updated in SMIv2 format before it can be advanced on the standards track.

Goals and Milestones:

Jan 00


Activation of working group, call for suggested MIB modules.

Feb 00


Reach agreement on the functional scope of the charter, and finalize the document deliverables.

Mar 00


Submit initial Internet-Draft for Differentiated Services Monitoring

Mar 00


Submit initial Internet-Draft for Interface TopN Reporting

Mar 00


Submit initial Internet-Draft for TR-RMON MIB in SMIv2 Format

Apr 00


Submit initial Internet-Draft for Application Performance Metrics

Jul 00


Begin Working Group Last Call for TR-RMON MIB in SMIv2 Format

Aug 00


Begin Working Group Last Call for Differentiated Services Monitoring

Aug 00


Begin Working Group Last Call for Interface TopN Reporting

Aug 00


Submit Final Draft of TR-RMON MIB in SMIv2 Format

Sep 00


Begin Working Group Last Call for Application Performance Metrics

Sep 00


Submit Final Draft of Differentiated Services Monitoring to IESG for standards track action

Sep 00


Submit Final Draft of Interface TopN Reporting to IESG for standards track action

Nov 00


Submit Final Draft of Application Performance Metrics to IESG for standards track action


Request For Comments:







Remote Network Monitoring Management Information Base



Remote Network Monitoring Management Information Base Version 2 using SMIv2



Remote Network Monitoring MIB Protocol Identifiers



Remote Network Monitoring MIB Extensions for Switch Networks Version 1.0

Current Meeting Report

Meeting Minutes: RMONMIB WG Interim

Area: OPS
Date: January 10 - 11, 2000
Time: 9:00 - 12:00, 13:00 - 18:00+ each day
Location: Boston, MA USA
Minutes: Andy Bierman & Russell Dietz

A) Agenda:

The RMONMIB WG will hold an interim meeting to focus on one new work item: Application Performance Measurement (APM). The WG has specific goals for the first phase of this work. Please read the charter text at: ftp://ftpeng.cisco.com/ftp/rmonmib/rmonmib_charter_nov99_b.txt

Day 1:
- Agenda bashing
- Translate APM charter text into APM functional requirements and scope of work.
- Discuss APM protocol classification framework
- includes protocol directory enhancements needed for APM
- Discuss APM metrics classification framework

Day 2:
- Discuss APM results classification and reporting framework
- includes bins vs. statistics discussion
- Examine existing APM I-D contributions and other published solution proposals
- draft-dietz-apmmon-mib-00.txt
- draft-warth-rmon2-artmib-01.txt
- others? (submission deadline is 1/8/00 17:00 EDT)
- Plan first release of APM document deliverables

B) Minutes

[Day 1 1/10/2000]

1) Agenda Bashing

No agenda changes were suggested, although the agenda order was not strictly followed.

2) Translate charter text into APM functional requirements

The meeting started by looking into the charter and how we should take the requirements and translate them into actual MIB implementation.

The charter text can be found at:

There was some general discussion on the measurements of application performance, and on the measurement of transport performance and the relationship to application performance.

2.2) Configuring the agent capabilities.

The group reached these conclusions:
- The APM standard does need to support installation and configuration of any specific APM measurement techniques.
- The APM standard should support client based, probe based, active and synthetic traffic monitoring, and even non-network based mechanisms.
- The focus of the APM standard will be on defining how the system reports and provides the information gathered via some APM collection technique.
- The APM standard must define the capabilities of the device, at various levels. An NMS application should expect the same results from different APM collection devices, for each 'test' with the same global ID and/or identical 'test' attributes.

2.3) APM Terms

The group then tried to establish some basic terms and an overall architectural model.

2.3.1) APM Data - The actual measurements, kept in some internal representation, collected from one or more APM Collection Points. This data is converted into one or more APM Reports, in an implementation-specific manner. APM Data is outside the scope of the APM standard.

2.3.2) APM Device - A device which contains an SNMP agent which implements the APM MIB. For the purpose of the standard, the APM device is the entity that is reporting the APM results, in the form of standard MIB objects. An APM Device can obtain APM data from one or more APM Collection Points.

2.3.3) APM Collection Point - The general location within the spectrum of possible vantage points, that APM Data is collected, for one or more APM Studies (and perhaps more than one APM device). The interaction between an APM device and and APM Collection Point is outside the scope of the APM standard.

2.3.4) APM Study Class - [called APM Study at the interim]
The unique set of parameters that distinguishes a particular APM collection mechanism and/or capability.
- the set of protocols collected
- test attributes (standard and proprietary)
- collection technique(s)
- APM Collection Point location(s)
- report capabilities
- global vendor ID
- vendor-specific Study Class ID

2.3.5) APM Study - [called APM Study instance at the interim]
This is an instantiation of a particular APM Study Class.
Some parameters, such as:
- the dataSource to monitor
- any resource restrictions to enforce
- the specific set of result data to collect
are relevant only in the context of an APM Study, not an APM Study Class.

2.3.6) APM Report Class - [not formalized at the interim]
The type of APM report produced on behalf of a particular APM Study Class. The group identified these distinct APM Report Classes:
- bin based aggregation
- statistical based aggregation
- exception based reporting

2.3.7) APM Report - the set of result data for a particular APM Study.
This is in the form of standard MIB objects and notifications in the APM MIB.

2.3.8) APM Location - the notion of where an APM Collection Point is obtaining APM Data. At the highest level, the possible locations are:
- client
- network
- server

The actual APM MIB will contain a more refined definition of APM Location.

2.3.9) APM Class - [not formalized at the meeting]
The group identified three classes of APM technology:
- passive collection: no test traffic is introduced into the system being measured. APM Data is derived from observable 'user activity' in the actual operating environment.
- active collection: some form of test traffic is introduced into the system being measured. APM Data is derived from measured attributes of this test traffic.
- intrusive collection: actual network traffic is modified for the purpose of APM Data collection. APM Data is derived from measured attributes of this modified network traffic.

2.4) Measuring the User Experience

The main goal of APM is to provide quantitative test results which directly reflect the experience perceived by the user of a network service. The group discussed examples such as:
- entire WEB page load time, not just an individual HTTP GETs
- entire application transaction time, not transport round trip time
- classification granularity to application verb level, since different verbs require different metrics

2.5) APM Functional Requirements Summary

The group listed these requirements at the end of this discussion:

- measure end-user experience
- link net based measurements
- probe caps
- test caps
- collect point caps
- notion of location
- no config, just start and stop tests
- quantitative analysis
- relation to RMON-2
- PD verbs
- finer classification:
- MIME type
- verbs
- relation to IPPM metrics
- don't reinvent terms
- dataSource granularity (not specific to APM)
- subset of an interface
- IP addresses

3) APM Framework

The group spent a great deal of time discussing APM Framework issues.

3.1) Metric Classification

Steve Waldbusser presented a model for classifying the user experience that was well-received by the group. At the highest level, the network interactions experienced by a real person can be divided into two metrics:
- Availability

- Responsiveness

At the highest level, the protocol types experienced by a real person can be divided into three classes:
- transaction-oriented

- throughput-oriented

- streaming-oriented

The following chart was presented and used for reference
throughout the meeting.

. Trans. Throughput Streaming
. +-------------------------------------------------------+
. | Availability | % avail. | % avail. | % avail. |
. +-------------------------------------------------------+
. | Responsiveness | tenths of | sec/Gbit | parts per |
. | | seconds | | million |
. +-------------------------------------------------------+

A great deal of discussion focused on complex protocols like 'WEB' (see sec x.x), and issues related to classifying transactions. Some 'meta-protocols' like this can be classified into different 'boxes', or classified into more than one box at once. Most protocols will fall into only one column, and both metrics for that column apply to the protocol.

A great deal of discussion focused on the availability metric for 'Streaming' protocols. It is roughly defined as the ratio of time that the service is degraded or interrupted to total service time, and is measured in parts per million.

It is difficult (through packet observation) to determine the true availability of some applications in this class, since many factors such as codec(s) used, negotiated bandwidth, playout buffer size, and user intervention (e.g. 'pause button'), influence the user experience.

Measuring the user experience for bi-directional streaming protocols (e.g., VOIP) is also quite difficult, and may require special consideration in the APM MIB.

The group discussed the units for the responsiveness metric. The units for all types of responsiveness metrics should be normalized, such that lower values indicate faster responsiveness.

3.2) APM Study Classification

Each APM Study Class has characteristics which must be identified by an NMS application, or order to properly interoperate with APM Devices.

3.2.1) APM Architecture

There are several distinct APM architectures which can be supported by the APM MIB. (See section 2.3.9).

3.2.2) Set of Metrics

The metrics supported by each APM Study Class must be identified in the APM standard.

3.2.3) Set of Protocols

The protocols supported by each APM Study Class must be identified in the APM standard. The RMON-2 protocolDirTable is used to identify protocols for APM.

3.2.4) APM Capabilities

The APM standard will contain support for identifying the generic feature capabilities of an APM Device, similar to the dataSourceCapsTable in the SMON MIB. This includes collection and output capabilities.

3.2.5) Vendor ID

Each APM Study Class must be assigned a unique 'registration OID' by the WG (for any standard APM study classes), or each vendor (for vendor-specific APM study classes).

3.3) APM Protocol Classification

The group discussed various aspects of protocol classification, and protocol directory enhancements that would benefit APM.

3.3.1) Meta Protocols

It is desirable to define a meta-protocols like 'WEB', to better measure the user experience. WEB (called capital-WEB), would represent a 'WEB page' as the transaction boundary, even though there may be many http flows needed to actually complete the 'WEB page transaction'. Meta-protocol capabilities and definitions need to be specified as extensions to the protocolDirectoryGroup of RMON-2.

3.3.2) APM Protocol Requirements

The following issues regarding protocols were raised:
Application performance and Network performance
- There is a need for a table that relates Application to Network protocols supported
- There may be a need for URL and Cookie analysis via Persistent names.

[Day 2: Tuesday 1/11/00]

3.3.3) Protocol Verbs

There was some discussion on the need for Protocol Verb Identifiers, similar to the PI Macros in RFC 2074. These verbs would need to be registered, and identified in a MIB. Text strings need to be handled somehow.

The WG may need a document that includes all of the VERBs or other test based elements that need children. May need to hand that off to IANA.

3.3.4) Security Considerations

There may be security implications for SSL, IP-sec, etc. Encouraging measurement could cause people to discourage deployment. There may also be security issues related to active monitoring, i.e., injection of packets into the network

3.4) APM Studies

The group agreed that the basic capabilities of each APM Study [Class] should be listed in a read-only MIB of some kind. The following attributes of an APM Study were listed:

APM Study =
- Set of application protocols
- Set of metrics
- Data Source
- Control of Output
- Output
- Distributions
- History
- Out of profile events

3.3.5) Partial Flows

There was some discussion on the impact of partial flow information on an APM Study and APM Reports. Partial flows can occur if an APM collection started after a flow, or an APM collection ends during a flow. There was concern about flow information appearing in more than one report. The 'curFlowTable' was left as a detail to be worked out later.

3.5) MIB Presentations

There were three MIBs presented to the group.

3.5.1) ART MIB (Albin Warth, Netscout)

Document: draft-warth-rmon2-artmib-01.txt

There was some discussion on the need for more metrics than just response time, and the use of one response time distribution configuration for all protocols. There was a lot of discussion on 'bins' vs. 'stats', which carried over into the next presentation. There is strong support for 'bins' (used in ART MIB), and not as much support for 'stats' (used in APMMON MIB).

3.5.2) APMMON MIB (Russell Dietz, Apptitude)

Document: draft-dietz-apmmon-mib-00.txt

Discussion focused mainly on the linkage between transport layer metrics and 'user experience metrics'. There was a lot of interest in 'drill-down metrics' and 'flow decomposition' for APM reports. The group decided these features are desirable, but they should be in another MIB, called the Transport Metrics MIB (TPM).

Another topic of interest was the use of statistical sampling data collection vs. pre-defined 'goodness range' distributions. It was decided that more work was needed, but the MIB(s) should (optionally) support both types of report output.

3.5.3) APM MIB (Steve Waldbusser, Lucent)

Document: not yet published

There was a lot of discussion on the aggregation methods in the APM Reports:
- Client-based aggregation
- Server-based aggregation
- client-server aggregation
- NO protocol or applications aggregation.

There was some discussion on a possible exception-based reporting mechanism, for flows or transactions that fall out of some range for some metric.

There was also some discussion on the possible need for a pre-filtering mechanism for flow analysis, e.g.,
filtering on addresses and/or protocols and/or applications.

4) Summary

The group listed the following 'To Do' list at the end of the meeting:

- persistent labels
- protocol verbs
- exception-based reporting
- pre-filter (select by net-address or protocol)
- APM Arch: type of transaction
- transaction-oriented
- throughput-oriented
- streaming-oriented
- APM Caps
- location
- vendor ID in study
- list of metrics
- microflows
- transaction in progress, partial flows

5) Attendees

Andy Bierman abierman@cisco.com
Russell Dietz rsdietz@apptitude.com
Bob Massad massadb@netscout.com
Albin Warth albin@netscout.com
Tom Nisbet tnisbet@visualnetworks.com
Emil Drottar emil_drottar@ne.3com.com
Adam Liss adam_liss@ion-networks.com
Pat Dochrty patrick_docherty@ion-networks.com
Carl Mower cmower@nortelnetworks.com
Brad Carey bradski@concord.com
Viveu Anand anand@nxs-americas.com
Gino Barille barille@swiss.nexus-ag.com
Brian Pratt pratt@nxs-americas.com
Renate Boergerding boergerding@swiss.nexus-ag.com
Raymond Chudzinski rchudzinski@verio.net
Bob Cole rgcole@att.com
Dan Romascanu dromasca@lucent.com
Dan Hansen dhansen@nai.com
Bert Wijnen wignen@vnet.ibm.com
Steve Waldbusser waldbusser@lucent.com
Shekhar Kshirsagar skshivsa@nortelnetworks.com
Russ Currie currier@netscout.com
Francisco Aquino faquino@concord.com


InterfaceTopN MIB
Transport Performance Metric MIB