doc: Add RFC documents

1 files changed, 899 insertions, 0 deletions

diff --git a/doc/rfc/rfc3134.txt b/doc/rfc/rfc3134.txt
new file mode 100644
index 0000000..aeff87b
--- /dev/null
+++ b/doc/rfc/rfc3134.txt
@@ -0,0 +1,899 @@
+
+
+
+
+
+
+Network Working Group                                            J. Dunn
+Request for Comments: 3134                                     C. Martin
+Category: Informational                                        ANC, Inc.
+                                                               June 2001
+
+
+                  Terminology for ATM ABR Benchmarking
+
+Status of this Memo
+
+   This memo provides information for the Internet community.  It does
+   not specify an Internet standard of any kind.  Distribution of this
+   memo is unlimited.
+
+Copyright Notice
+
+   Copyright (C) The Internet Society (2001).  All Rights Reserved.
+
+Abstract
+
+   This memo discusses and defines terms associated with performance
+   benchmarking tests and the results of these tests in the context of
+   Asynchronous Transfer Mode (ATM) based switching devices supporting
+   ABR (Available Bit Rate).  The terms defined in this memo will be
+   used in addition to terms defined in RFCs 1242, 2285, and 2544 and
+   2761.  This memo is a product of the Benchmarking Methodology Working
+   Group (BMWG) of the Internet Engineering Task Force (IETF).
+
+1. Introduction
+
+   This document provides terminology for benchmarking ATM based
+   switching devices supporting ABR.  It extends terminology already
+   defined for benchmarking network interconnect devices in RFC's 1242,
+   2285, and 2544 and 2761.  Although some of the definitions in this
+   memo may be applicable to a broader group of network interconnect
+   devices, the primary focus of the terminology in this memo is on ATM
+   ABR.
+
+   This memo contains two major sections: Background and Definitions.
+   The background section provides the reader with an overview of the
+   technology and IETF formalisms.  The definitions section is split
+   into two sub-sections.  The formal definitions sub-section is
+   provided as a courtesy to the reader.  The measurement definitions
+   sub-section contains performance metrics with inherent units.
+
+   This document assumes that necessary services are available and
+   active.  For example, IP connectivity requires SSCOP connectivity
+   between signaling entities.  Further, it is assumed that the SUT has
+
+
+
+Dunn & Martin                Informational                      [Page 1]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   the ability to configure ATM addresses (via hard coded addresses,
+   ILMI or PNNI neighbor discovery), has the ability to run SSCOP, and
+   has the ability to perform signaled call setups (via UNI or PNNI
+   signaling).  Finally, this document presents only the terminology
+   associated with benchmarking IP performance over ATM; therefore, it
+   does not represent a total compilation of ATM test terminology.
+
+   The BMWG produces two major classes of documents: Benchmarking
+   Terminology documents and Benchmarking Methodology documents.  The
+   Terminology documents present the benchmarks and other related terms.
+   The Methodology documents define the procedures required to collect
+   the benchmarks cited in the corresponding Terminology documents.
+
+2. Existing Definitions.
+
+   RFC 1242, "Benchmarking Terminology for Network Interconnect
+   Devices", should be consulted before attempting to make use of this
+   document.  RFC 2544, "Benchmarking Methodology for Network
+   Interconnect Devices", contains discussions of a number of terms
+   relevant to the benchmarking of switching devices and should be
+   consulted.  RFC 2285, "Benchmarking Terminology for LAN Switching
+   Devices", contains a number of terms pertaining to traffic
+   distributions and datagram interarrival.  RFC 2761, "Terminology for
+   ATM Benchmarking", contains a number terms pertaining to traffic
+   management [TM4.0, TM4.1].  Many of the metrics defined in RFC 2761
+   (e.g., CDV, CER, CLR, CMR, and CTD) also apply to ABR performance
+   benchmarking.  These metrics will not be redefined in this document.
+   For the sake of clarity and continuity, this RFC adopts the template
+   for definitions set out in Section 2 of RFC 1242.
+
+II. Definitions
+
+   The definitions presented in this section have been divided into two
+   groups.  The first group is formal definitions, which are required in
+   the definitions of the performance metrics but are not themselves
+   strictly metrics.  These definitions are subsumed from other work
+   done in other working groups both inside and outside the IETF.  They
+   are provided as a courtesy to the reader.
+
+1. Formal Definitions
+
+1.1. Definition Format (from RFC 1242)
+
+   Term to be defined.
+
+   Definition: The specific definition for the term.
+
+
+
+
+
+Dunn & Martin                Informational                      [Page 2]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   Discussion: A brief discussion of the term, its application and any
+   restrictions on measurement procedures.
+
+   Specification: The working group and document in which the terms are
+   specified and are listed in the references section.
+
+1.2. Related Definitions.
+
+1.2.1. Allowed Cell Rate (ACR)
+
+   Definition: An ABR service parameter, ACR is the current rate
+   (cells/second) at which a source is allowed to send.
+
+   Discussion: For ABR traffic, ACR constitutes the actual data
+   throughput for a particular VC.  The time change of this value
+   effects TCP round trip time calculations, which in turn effects TCP
+   throughput.
+
+   Specification: AF-TM4.0
+
+1.2.2. ACR Decrease Time Factor (ADTF)
+
+   Definition: This is the time permitted between sending RM-cells
+   before the rate is decreased to ICR (Initial Cell Rate). The time
+   units are .01 to 10.23 seconds with a granularity of 10 ms.
+
+   Discussion: For ABR traffic, ADTF constitutes the time rate of the
+   ACR.  This value effects TCP round trip time calculations, which in
+   turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+1.2.3. Additive Increase Rate (AIR)
+
+   Definition: An ABR service parameter, AIR controls the rate at which
+   the cell transmission rate increases.  It is signaled as AIRF, where
+
+       AIRF = AIR*Nrm/PCR.
+
+   Discussion: For ABR traffic, AIR effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+1.2.4. Additive Increase Rate Factor (AIRF)
+
+   Definition: Refer to AIR.
+
+
+
+Dunn & Martin                Informational                      [Page 3]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   Discussion: Refer to AIR.
+
+   Specification: AF-TM4.0
+
+1.2.5. Available Bit Rate (ABR)
+
+   Definition: ABR is an ATM layer service category for which the
+   limiting ATM layer transfer characteristics provided by the network
+   may change subsequent to connection establishment.  A flow control
+   mechanism is specified which supports several types of feedback to
+   control the source rate in response to changing ATM layer transfer
+   characteristics.
+
+   Discussion: It is expected that an end-system that adapts its traffic
+   in accordance with the feedback will experience a low cell loss ratio
+   and obtain a fair share of the available bandwidth according to a
+   network specific allocation policy.  Cell delay variation is not
+   controlled in this service, although admitted cells are not delayed
+   unnecessarily.
+
+   Specification: AF-TM4.1
+
+1.2.6. Available Bit Rate (ABR) Compliance (Conformance)
+
+   Definition: ABR connection conformance refers to the behavior
+   specified for ABR destination and switches, but allows for delays
+   between the source and the UNI [UNI3.1, UNI4.0], which may perturb
+   the traffic flow.
+
+   Discussion: The cells on an ABR connection applies to CLP=0 cells,
+   which are tested upon arrival.  At the arrival point, each cell is
+   identified as conforming or non-conforming.  The minimal conformance
+   definition for ABR is GCRA((1/PCR),t1), where PCR is defined for
+   CLP=0 flow.
+
+   Specification: AF-TM4.1
+
+1.2.7. BN
+
+   Definition: The BN bit in the RM-cell indicated whether the RM-cell
+   is a BECN cell or not.
+
+   Discussion: If BN=0, the RM cells were generated by the source.  If
+   BN=1, the RM cells were generated by the destination or a switch.
+
+   Specification: AF-TM4.1
+
+
+
+
+
+Dunn & Martin                Informational                      [Page 4]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+1.2.8. CCR
+
+   Definition: The CCR field in the RM-cell is set by the source to its
+   current ACR.  CCR is formatted as a rate.
+
+   Discussion: For BECN cells, CCR=0.
+
+   Specification: AF-TM4.1
+
+1.2.9. Cell Blocks (CB)
+
+   Definition: Cell blocks are a sequence of N cells transmitted
+   consecutively on a given connection.
+
+   Discussion: A cell block will normally correspond to the number of
+   information cells transmitted between successive OAM cells.
+
+   Specification: AF-TM4.1
+
+1.2.10. Congestion Indication (CI)
+
+   Definition: The CI bit in the RM-cell allows a network element to
+   indicate that there is congestion in the network.
+
+   Discussion: When the source receives a backward RM-cell with CI=1,
+   ACR is decreased.  When the destination turns around a forward RM-
+   cell, the CI is set to 1 to indicate that the previously received
+   data cell had the EFCI state set.
+
+   Specification: AF-TM4.1
+
+1.2.11. Cutoff Decrease Factor (CDF)
+
+   Definition: CDF controls the decrease in ACR (Allowed Cell Rate)
+   associated with CRM (missing RM cell count).
+
+   Discussion: For ABR traffic, CDF effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+
+
+
+
+
+
+
+
+
+Dunn & Martin                Informational                      [Page 5]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+1.2.12. DIR
+
+   Definition: The DIR bit in the RM-cell indicates which direction of
+   data flow is associated with the RM-cell.  DIR is changed from 0 to 1
+   when an RM-cell is turned around at the destination.
+
+   Discussion: A forward RM-cell is indicated by DIR=0 and is associated
+   with data cells flowing in the same direction.  A backward RM-cell is
+   indicated by DIR=1 and is associated with data cells flowing in the
+   opposite direction.
+
+   Specification: AF-TM4.1
+
+1.2.13. Explicit Rate (ER)
+
+   Definition: The ER field in the RM-cell is used to limit the source
+   ACR to a specific value.  For each RM-cell, ER is set by the source
+   to a requested rate (e.g., PCR).  It may be reduced by any network
+   element in the path to a value that the element can sustain.  ER is
+   formatted as a rate.
+
+   Discussion: None.
+
+   Specification: AF-TM4.1
+
+1.2.14. Feedback
+
+   Definition: Information carried in the backward RM-cells provided by
+   the network elements and/or the destination back to the source.
+
+   Discussion: Feedback may include information in the ER field, or the
+   CI or NI bits of each backward RM-cell.
+
+   Specification: AF-TM4.1
+
+1.2.15. Ideal Transmission Time (ITT)
+
+   Definition: The transmission time for ABR CLP=0 cells, if the
+   difference between itself and the transmission time for the previous
+   CLP=0 cell on the connection is greater than or equal to the minimum:
+   a) the inverse of the ACR in effect immediately after the
+   transmission time of the first of the two cells b) the inverse of the
+   ACR in effect immediately before the transmission time of the second
+   of the two cells.
+
+   Discussion: The transmission time for the first cell on the
+   connection is automatically an ITT.
+
+
+
+
+Dunn & Martin                Informational                      [Page 6]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   Specification: AF-TM4.1
+
+1.2.16. Initial Cell Rate (ICR)
+
+   Definition: An ABR service parameter, in cells/sec, that is the rate
+   at which a source should send initially and after an idle period.
+
+   Discussion: none.
+
+   Specification: AF-TM4.0
+
+1.2.17. In-Rate Cells
+
+   Definition: In-Rate ABR cells are sent with CLP=0.
+
+   Discussion: ABR RM-cells shall be sent with CLP=0 except in certain
+   circumstances, See Out-of-Rate Cells.  All other ABR cells shall be
+   sent with CLP=0.
+
+   Specification: AF-TM4.1
+
+1.2.18. Minimum Cell Rate (MCR)
+
+   Definition: An ABR service traffic descriptor, in cells/sec, that is
+   the rate at which the source is always allowed to send.
+
+   Discussion: MCR may be set to zero.  The bandwidth available from the
+   network may vary, but shall not become less than MCR.
+
+   Specification: AF-TM4.1
+
+1.2.19. Mrm
+
+   Definition: An ABR service parameter that controls allocation of
+   bandwidth between forward W-cells, backward RM-cells, and data cells.
+
+   Discussion: none.
+
+   Specification: AF-TM4.0
+
+1.2.20. No Increase (NI)
+
+   Definition: The NI bit in the RM-cell is used to prevent a source
+   from increasing its ACR.  NI does not require any decrease in value.
+
+   Discussion: None.
+
+   Specification: AF-TM4.0
+
+
+
+Dunn & Martin                Informational                      [Page 7]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+1.2.21. Nrm
+
+   Definition: An ABR service parameter, Nrm is the maximum number of
+   cells a source may send for each forward RM-cell.
+
+   Discussion: none.
+
+   Specification: AF-TM4.0
+
+1.2.22. Out-of-Rate Cells
+
+   Definition: Out-of-Rate ABR cells are sent with CLP=1.
+
+   Discussion: This may be used to enable a rate increase for a
+   connection that has an ACR=0.  The source would generate out-of-rate
+   cells to probe the network to learn when it may increase its rate.
+
+   Specification: AF-TM4.1
+
+1.2.23. Rate Decrease Factor (RDF)
+
+   Definition: An ABR service parameter, RDF controls the decrease in
+   the cell transmission rate.  RDF is a power of 2 from 1/32,768 to 1.
+
+   Discussion: For ABR traffic, RDF effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+1.2.24. Rate Increase Factor (RIF)
+
+   Definition: This controls the amount by which the cell transmission
+   rate may increase upon receipt of a RM-cell.  The additive increase
+   rate AIR=PCR*RIF.  RIF is a power of 2, ranging from 1/32,768 to 1.
+
+   Discussion: For ABR traffic, RIF effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+1.2.25. Resource Management (RM) Cells
+
+   Definition: RM cells are used to convey network status  (available
+   bandwidth, congestion levels) and request peak cell rates for ATM
+   blocks.  The RM cell has the following format:
+
+
+
+
+Dunn & Martin                Informational                      [Page 8]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   Header: 5 bytes, same as the ATM cell header Protocol ID: 3 bytes,
+   protocol ID value is 1 for ABR service Function specific field: 45
+   bytes, data required for the specific protocol (See DIR, BN, CI, NI,
+   ER, CCR, and MCR for field information.)  Rsvd: 6 bytes, reserved for
+   future specification EDC: 10 bytes, CRC-10 error detection code
+   computed over the cell payload .ti6 (except the CRC-10 field) and
+   used to check for data corruption
+
+   Discussion: RM information can exist at the VP and/or VC level.  VP
+   level cells are identified with a VCI value of 6.  VC level cells are
+   identified with a PT of 6.  See DIR, BN, CI, NI, ER, CCR, and MCR for
+   additional protocol field information.
+
+   Specification: AF-TM4.0
+
+1.2.26. Severely Errored Cell Block (SECB)
+
+   Definition: A severely cell block outcome occurs when more than M
+   errored cells, lost cells, or misinserted cell outcomes are observed
+   in a received cell block.
+
+   Discussion: none.
+
+   Specification: AF-TM4.1
+
+1.2.27. Tagged Cell Rate (TCR)
+
+   Definition: An ABR service parameter, TCR limits the rate at which a
+   source may send out-of-rate forward RM-cells.  TCR is a constant
+   fixed at 10 cells/second.
+
+   Discussion: none.
+
+   Specification: AF-TM4.0
+
+1.2.28. TDF
+
+   Definition: An ABR service parameter, TDF controls the decrease in
+   ACR associated with TOF.  TDF is signaled as TDFF, where TDF=TDFF/RDF
+   times the smallest power of 2 greater or equal to PCR.  TDF is in
+   units of 1/seconds.
+
+   Discussion: For ABR traffic, TDF effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+
+
+
+Dunn & Martin                Informational                      [Page 9]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+1.2.29. TDFF
+
+   Definition: Refer to TDF.  TDFF is either zero or a power of two in
+   the range 1/64 to 1 in units of 1 /cells.
+
+   Discussion: Refer to TDF.
+
+   Specification: AF-TM4.0
+
+   1.2.30. Time Out Factor (TOF)
+
+   Definition: An ABR service parameter, TOF controls the maximum time
+   permitted between sending forward RM-cells before a rate decrease is
+   required.  It is signaled as TOFF where TOF=TOFF+1.  TOFF is a power
+   of 2 in the range: 1/8 to 4,096.
+
+   Discussion: For ABR traffic, TOF effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+1.2.31. Time Out Factor (TOFF)
+
+   Definition: Refer to TOF.
+
+   Discussion: none.
+
+   Specification: AF-TM4.0
+
+1.2.32. Trm
+
+   Definition: An ABR service parameter that provides an upper bound on
+   the time between forward RM-cells for an active source.  It is 100
+   times a power of two with a range of 100*2-7 to 100*20
+
+   Discussion: For ABR traffic, Trm effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+1.2.33. Virtual Source/Virtual Destination (VSND)
+
+   Definition: An ABR connection may be divided into two or more
+   separately controlled ABR segments.  Each ABR control segment, except
+   the first, is sourced by a virtual source.  A virtual source
+   implements the behavior of an ABR source endpoint.  Backward RM-cells
+
+
+
+Dunn & Martin                Informational                     [Page 10]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   received by a virtual source are removed from the connection.  Each
+   ABR control segment, except the last, is terminated by a virtual
+   destination.  A virtual destination assumes the behavior of an ABR
+   destination endpoint.  Forward RM-cells received by a virtual
+   destination are turned around and not forwarded to the next segment
+   of the connection.
+
+   Discussion: none.
+
+   Specification: AF-TM4.0
+
+1.2.34. Xrm Decrease Factor (XDM)
+
+   Definition: An ABR service parameter, XDF controls the decrease in
+   ACR associated with Xrm.  It is a power of two in range: [0, 1].
+
+   Discussion: For ABR traffic, XDM effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+1.2.35. Xrm
+
+   Definition: An ABR service parameter, Xrm limits the number of
+   forward RM-cells which may be sent in the absence of received
+   backward PM-cells.  The range is 0-255.
+
+   Discussion: For ABR traffic, Xrm effects the time rate of change of
+   the ACR.  This value effects TCP round trip time calculations, which
+   in turn effects TCP throughput.
+
+   Specification: AF-TM4.0
+
+2. Performance Metrics
+
+2.1. Definition Format (from RFC 1242)
+
+   Metric to be defined.
+
+   Definition: The specific definition for the metric.
+
+   Discussion: A brief discussion of the metric, its application and any
+   restrictions on measurement procedures.
+
+   Measurement units: Intrinsic units used to quantify this metric.
+   This includes subsidiary units; e.g., microseconds are acceptable if
+   the intrinsic unit is seconds.
+
+
+
+Dunn & Martin                Informational                     [Page 11]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+2.2. Definitions
+
+2.2.1. ABR Rate Decrease Response Time (ARDRT)
+
+   Definition: The amount of time required by the SUT to adjust its
+   transmission rate based on an ABR rate decrease request.
+
+   Discussion:  During the ARDRT, cells transmitted by the SUT may be
+   dropped by the network due to traffic policing.  These dropped cells
+   may contain a portion of an IP datagram.  This may cause IP and TCP
+   packet loss.
+
+   Measurement Units: seconds
+
+2.2.2. ABR Rate Increase Response Time (ARIRT)
+
+   Definition: The amount of time required by the SUT to adjust its
+   transmission rate based on an ABR rate increase request.
+
+   Discussion: During the ARIRT, the SUT will not fully utilize the
+   available bandwidth.  This will negatively impact IP and TCP
+   throughput.
+
+   Measurement Units: seconds
+
+2.2.3. RM-Cell Delay Variation (RM-CDV)
+
+   Definition: The variation in RM-cell transfer delay (RM-CTD) of RM-
+   cells associated with a given traffic load, orientation and
+   distribution, as well as an integration period.  RM-CDV = max (RM-
+   CTD) - min (RM-CTD) where max and min indicate the maximum and
+   minimum over the integration period, respectively.
+
+   Discussion:  RM-CDV is a component of RM-cell transfer delay, induced
+   by buffering and RM-cell scheduling.
+
+   RM-CDV effects the time required to notify the source of a change in
+   the condition of the network.  This in turn effects TCP round trip
+   time calculations. Large values of RM-CDV will adversely effect TCP
+   throughput and cause SAR timeout.
+
+   Measurement Units: seconds
+
+2.2.4. RM-Cell Error Ratio (RM-CER)
+
+   Definition: The ratio of RM-cells with payload errors in a
+   transmission in relation to the total number of RM-cells sent in a
+   transmission associated with a given traffic load, orientation and
+
+
+
+Dunn & Martin                Informational                     [Page 12]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   distribution, as well as an integration period. Note that errors
+   occurring in the RM-cell header will cause RM-cell loss at the ATM
+   layer. Note further that multiple errors in a payload will only be
+   counted as one cell payload error.
+
+     RM-CER = RM-Cells with payload errors / Total RM-Cells Transmitted.
+
+   Discussion: The measurement is taken over a time interval and is
+   desirable to be measured on an in-service circuit. RM-CER effects the
+   time required to notify the source of a change in the condition of
+   the network. This in turn effects TCP round trip time calculations.
+   Large values of RM-CER will adversely effect TCP throughput and cause
+   SAR timeout.
+
+   Measurement Units: dimensionless.
+
+2.2.5. RM-Cell Loss Ratio (RM-CLR)
+
+   Definition: The ratio of lost RM-cells in a transmission in relation
+   to the total RM-cells sent in a transmission associated with a given
+   traffic load, orientation and distribution, as well as an integration
+   period.
+
+      RM-CLR = Lost RM-Cells / Total RM-Cells Transmitted.
+
+   Discussion: The objective is to minimize RM-CLR.  It is expressed as
+   an order of magnitude, having a range of 10^-1 to 10^-15 and
+   unspecified.
+
+   RM-CLR effects the time required to notify the source of a change in
+   the condition of the network.  This in turn effects TCP round trip
+   time calculations.  Large values of RM-CLR will adversely effect TCP
+   throughput and cause SAR timeout.
+
+   Measurement Units: dimensionless.
+
+2.2.6. RM-Cell Misinsertion Ratio (RM-CMR)
+
+   Definition: The ratio of RM-cells received at an endpoint that were
+   not originally transmitted by the source end in relation to the total
+   number of RM-cells properly transmitted associated with a given
+   traffic load, orientation and distribution, as well as an integration
+   period.
+
+      RM-CMR = Misinserted RM-Cells / Total RM-Cells Transmitted.
+
+
+
+
+
+
+Dunn & Martin                Informational                     [Page 13]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   Discussion: The measurement is taken over a time interval and is
+   desirable to be measured on an in-service circuit.
+
+   RM-CMR effects the time required to notify the source of a change in
+   the condition of the network.  This in turn effects TCP round trip
+   time calculations.  Large values of RM-CMR will adversely effect TCP
+   throughput and cause SAR timeout.
+
+   Measurement Units: dimensionless.
+
+2.2.7. RM-CRC Error Ratio
+
+   Definition: The ratio of RM-cells received at an endpoint which
+   contain an invalid CRC in relation to the total number of RM-cells
+   properly transmitted associated with a given traffic load,
+   orientation and distribution, as well as an integration period.
+
+   Discussion: RM-CRC errors cause ATM RM-cells to be lost.
+
+   RM-CRC effects the time required to notify the source of a change in
+   the condition of the network.  This in turn effects TCP round trip
+   time calculations.  Large values of RM-CRC will adversely effect TCP
+   throughput and cause SAR timeout.
+
+   Measurement Units: dimensionless
+
+2.2.8. RM-Cell Transfer Delay (RM-CTD)
+
+   Definition: The elapsed time between a RM-cell exit event at the
+   measurement point 1 (e.g., at the source UNI) and the corresponding
+   RM-cell entry event at a measurement point 2 (e.g., the destination
+   UNI) for a particular connection.
+
+   Discussion: The RM-cell transfer delay between two measurement points
+   is the sum of the total inter-ATM node transmission delay and the
+   total ATM node processing delay.  This number is a constant and
+   should not adversely effect performance.
+
+   Measurement units: seconds
+
+2.2.9. Severely Errored Cell Block Ratio (SECBR)
+
+   Definition: The ratio of severely errored cell blocks in a
+   transmission in relation to the total cell blocks sent in a
+   transmission associated with a given traffic load, orientation and
+   distribution, as well as an integration period.
+
+      SECBR = Severely Errored Cell Blocks/Total Transmitted Cell Blocks
+
+
+
+Dunn & Martin                Informational                     [Page 14]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+   Discussion: SECBR may cause the SUT to drop cells that may contain a
+   portion of an IP datagram.  This may cause IP and TCP packet loss.
+
+   Measurement Units: dimensionless.
+
+3. Security Considerations
+
+   As this document is solely for providing terminology and describes
+   neither a protocol nor an implementation, there are no security
+   considerations associated with this document.
+
+4. References
+
+   [AF-TM4.0]  ATM Forum, Traffic Management Specification Version 4.0,
+               af-tm-0056.00, April 1996.
+
+   [AF-TM4.1]  ATM Forum, Traffic Management Specification Version 4.1,
+               af-tm-0121.000, March 1999.
+
+   [AF-UNI3.1] ATM Forum, User Network Interface Specification Version
+               3.1, September 1994.
+
+   [AF-UNI4.0] ATM Forum, User Network Interface Specification Version
+               4.0, July 1996.
+
+5. Editors' Addresses
+
+   Jeffrey Dunn
+   Advanced Network Consultants, Inc.
+   4214 Crest Place
+   Ellicott City, MD 21043 USA
+
+   Phone: +1 (410) 750-1700
+   EMail: Jeffrey.Dunn@worldnet.att.net
+
+
+   Cynthia Martin
+   Advanced Network Consultants, Inc.
+   4214 Crest Place
+   Ellicott City, MD 21043 USA
+
+   Phone: +1 (410) 750-1700
+   EMail: Cynthia.E.Martin@worldnet.att.net
+
+
+
+
+
+
+
+
+Dunn & Martin                Informational                     [Page 15]
+
+RFC 3134          Terminology for ATM ABR Benchmarking         June 2001
+
+
+Full Copyright Statement
+
+   Copyright (C) The Internet Society (2001).  All Rights Reserved.
+
+   This document and translations of it may be copied and furnished to
+   others, and derivative works that comment on or otherwise explain it
+   or assist in its implementation may be prepared, copied, published
+   and distributed, in whole or in part, without restriction of any
+   kind, provided that the above copyright notice and this paragraph are
+   included on all such copies and derivative works.  However, this
+   document itself may not be modified in any way, such as by removing
+   the copyright notice or references to the Internet Society or other
+   Internet organizations, except as needed for the purpose of
+   developing Internet standards in which case the procedures for
+   copyrights defined in the Internet Standards process must be
+   followed, or as required to translate it into languages other than
+   English.
+
+   The limited permissions granted above are perpetual and will not be
+   revoked by the Internet Society or its successors or assigns.
+
+   This document and the information contained herein is provided on an
+   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
+   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
+   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
+   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
+   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
+
+Acknowledgement
+
+   Funding for the RFC Editor function is currently provided by the
+   Internet Society.
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+Dunn & Martin                Informational                     [Page 16]
+