Network Working Group                   J. H. Dunn
INTERNET-DRAFT                       C. E. Martin
Expires: February, August, 2001                  ANC, Inc.

                                                           July, 2000

                              April, 2001
          Terminology for ATM ABR Benchmarking
                   <draft-ietf-bmwg-atm-term-abr-02.txt>
          <draft-ietf-bmwg-atm-term-abr-03.txt>

Status of this Memo

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Copyright Notice

  Copyright (C) The Internet Society (1999). 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.
  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 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.

3. Requirements

   In this document, the words that are used to define the significance  of
   each particular requirement are capitalized. These words are:

   *  "MUST"  This  word, or the words "REQUIRED" and "SHALL" mean that the
   item is an absolute requirement of the specification.

   * "SHOULD" This word or the adjective "RECOMMENDED" means that there may
   exist valid reasons in particular circumstances to ignore this item, but
   the full implications  should  be  understood  and  the  case  carefully
   weighed before choosing a different course.

   *  "MAY"  This  word or the adjective "OPTIONAL" means that this item is
   truly optional.  One vendor may choose to include  the  item  because  a
   particular  marketplace  requires it or because it enhances the product,
   for example; another vendor may omit the same item.

   An implementation is not compliant if it fails to satisfy one or more of
   the   MUST   requirements   for   the   protocols   it  implements.   An
   implementation  that  satisfies  all  the  MUST  and  all   the   SHOULD
   requirements   for   its   protocols  is  said  to  be  "unconditionally
   compliant"; one that satisfies all the MUST requirements but not all the
   SHOULD  requirements  for  its  protocols  is  said to be "conditionally
   compliant".

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.

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.

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 wheather 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

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

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.

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

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 increate 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:

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
   (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

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 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.

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 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.

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

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. Notices

Internet Engineering Task Force
  The IETF takes no position regarding the validity or scope of any
  intellectual property or other rights that might be claimed to pertain
  to the implementation or use of the technology described in this
  document or the extent to which any license under such rights might or
  might not be available; neither does it represent that it has made any
  effort to identify any such rights. Information on the IETFs procedures
  with respect to rights in standards-track  and  standards-related
  documentation can be found in BCP-11. Copies of claims of rights made
  available for publication and any assurances of licenses to be made
  available, or the result of an attempt made to obtain a general license
  or permission for the use of such proprietary rights by implementors or
  users of this specification can be obtained from the IETF Secretariat.

  The IETF invites any interested party to bring to its attention any
  copyrights, patents or patent applications, or other proprietary rights,
  which may cover technology that may be required to practice this
  standard.  Please address the information to the IETF  Executive
  Director.

5. Disclaimer

  Copyright (C) The Internet Society (1999). 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
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  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.

6. 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.

7. Editors Addresses

  Jeffrey Dunn
  Advanced Network Consultants, Inc.
  4214 Crest Place, Ellicott City, MD 21043 USA
  Phone: +1 (410) 750-1700, E-mail: Jeffrey.Dunn@worldnet.att.net

  Cynthia Martin
  Advanced Network Consultants, Inc.
  4214 Crest Place, Ellicott City, MD 21043 USA
  Phone: +1 (410) 750-1700, E-mail: Cynthia.E.Martin@worldnet.att.net