draft-ietf-ippm-loss-04.txt   draft-ietf-ippm-loss-05.txt 
Network Working Group G. Almes Network Working Group G. Almes
INTERNET-DRAFT S. Kalidindi INTERNET-DRAFT S. Kalidindi
Expiration Date: March 1999 M. Zekauskas Expiration Date: May 1999 M. Zekauskas
Advanced Network & Services Advanced Network & Services
August 1998 November 1998
A Packet Loss Metric for IPPM A One-way Packet Loss Metric for IPPM
<draft-ietf-ippm-loss-04.txt> <draft-ietf-ippm-loss-05.txt>
1. Status of this Memo 1. Status of this Memo
This document is an Internet-Draft. Internet-Drafts are working This document is an Internet-Draft. Internet-Drafts are working
documents of the Internet Engineering Task Force (IETF), its areas, documents of the Internet Engineering Task Force (IETF), its areas,
and its working groups. Note that other groups may also distribute and its working groups. Note that other groups may also distribute
working documents as Internet Drafts. working documents as Internet-Drafts.
Internet-Drafts are draft documents valid for a maximum of six Internet-Drafts are draft documents valid for a maximum of six
months, and may be updated, replaced, or obsoleted by other documents months, and may be updated, replaced, or obsoleted by other documents
at any time. It is inappropriate to use Internet- Drafts as at any time. It is inappropriate to use Internet-Drafts as reference
reference material or to cite them other than as "work in progress." material or to cite them other than as "work in progress."
To view the entire list of current Internet-Drafts, please check the To view the entire list of current Internet-Drafts, please check the
"1id-abstracts.txt" listing contained in the Internet-Drafts shadow "1id-abstracts.txt" listing contained in the Internet-Drafts shadow
directories on ftp.is.co.za (Africa), nic.nordu.net (Northern directories on ftp.is.co.za (Africa), nic.nordu.net (Northern
Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific Europe), ftp.nis.garr.it (Southern Europe), munnari.oz.au (Pacific
Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast). Rim), ftp.ietf.org (US East Coast), or ftp.isi.edu (US West Coast).
This memo provides information for the Internet community. This memo This memo provides information for the Internet community. This memo
does not specify an Internet standard of any kind. Distribution of does not specify an Internet standard of any kind. Distribution of
this memo is unlimited. this memo is unlimited.
2. Introduction 2. Introduction
This memo defines a metric for packet loss across Internet paths. It This memo defines a metric for one-way packet loss across Internet
builds on notions introduced and discussed in the IPPM Framework paths. It builds on notions introduced and discussed in the IPPM
document, RFC 2330 [1]; the reader is assumed to be familiar with Framework document, RFC 2330 [1]; the reader is assumed to be
that document. familiar with that document.
This memo is intended to be parallel in structure to a companion This memo is intended to be parallel in structure to a companion
document for One-way Delay (currently "A One-way Delay Metric for document for One-way Delay (currently "A One-way Delay Metric for
IPPM" <draft-ietf-ippm-delay-04.txt>) [2]; the reader is assumed to IPPM" <draft-ietf-ippm-delay-05.txt>) [2]; the reader is assumed to
be familiar with that document. be familiar with that document.
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [5].
Although RFC 2119 was written with protocols in mind, the key words
are used in this document for similar reasons. They are used to
ensure the results of measurements from two different implementations
are comparable, and to note instances when an implementation could
perturb the network.
The structure of the memo is as follows: The structure of the memo is as follows:
+ A 'singleton' analytic metric, called Type-P-One-way-Loss, is + A 'singleton' analytic metric, called Type-P-One-way-Loss, is
introduced to measure a single observation of packet transmission introduced to measure a single observation of packet transmission
or loss. or loss.
+ Using this singleton metric, a 'sample', called Type-P-One-way- + Using this singleton metric, a 'sample', called Type-P-One-way-
Loss-Poisson-Stream, is introduced to measure a sequence of Loss-Poisson-Stream, is introduced to measure a sequence of
singleton transmissions and/or losses measured at times taken from singleton transmissions and/or losses measured at times taken from
a Poisson process. a Poisson process.
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real-time applications (where the precise threshold of "excessive" real-time applications (where the precise threshold of "excessive"
depends on the application). depends on the application).
+ The larger the value of packet loss, the more difficult it is for + The larger the value of packet loss, the more difficult it is for
transport-layer protocols to sustain high bandwidths. transport-layer protocols to sustain high bandwidths.
+ The sensitivity of real-time applications and of transport-layer + The sensitivity of real-time applications and of transport-layer
protocols to loss become especially important when very large protocols to loss become especially important when very large
delay-bandwidth products must be supported. delay-bandwidth products must be supported.
The measurement of one-way loss instead of round-trip loss is
motivated by the following factors:
+ In today's Internet, the path from a source to a destination may
be different than the path from the destination back to the source
("asymmetric paths"), such that different sequences of routers are
used for the forward and reverse paths. Therefore round-trip
measurements actually measure the performance of two distinct
paths together. Measuring each path independently highlights the
performance difference between the two paths which may traverse
different Internet service providers, and even radically different
types of networks (for example, research versus commodity
networks, or ATM versus packet-over-SONET).
+ Even when the two paths are symmetric, they may have radically
different performance characteristics due to asymmetric queueing.
+ Performance of an application may depend mostly on the performance
in one direction. For example, a file transfer using TCP may
depend more on the performance in the direction that data flows,
rather than the direction in which acknowledgements travel.
+ In quality-of-service (QoS) enabled networks, provisioning in one
direction may be radically different than provisioning in the
reverse direction, and thus the QoS guarantees differ. Measuring
the paths independently allows the verification of both
guarantees.
It is outside the scope of this document to say precisely how loss It is outside the scope of this document to say precisely how loss
metrics would be applied to specific problems. metrics would be applied to specific problems.
2.2. General Issues Regarding Time 2.2. General Issues Regarding Time
Whenever a time (i.e., a moment in history) is mentioned here, it is Whenever a time (i.e., a moment in history) is mentioned here, it is
understood to be measured in seconds (and fractions) relative to UTC. understood to be measured in seconds (and fractions) relative to UTC.
As described more fully in the Framework document, there are four As described more fully in the Framework document, there are four
distinct, but related notions of clock uncertainty: distinct, but related notions of clock uncertainty:
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example, the clock on an old Unix host might advance only once example, the clock on an old Unix host might advance only once
every 10 msec, and thus have a resolution of only 10 msec. every 10 msec, and thus have a resolution of only 10 msec.
skew* skew*
Skew measures the change of accuracy, or of synchronization, Skew measures the change of accuracy, or of synchronization,
with time. For example, the clock on a given host might gain with time. For example, the clock on a given host might gain
1.3 msec per hour and thus be 27.1 msec behind UTC at one time 1.3 msec per hour and thus be 27.1 msec behind UTC at one time
and only 25.8 msec an hour later. In this case, we say that the and only 25.8 msec an hour later. In this case, we say that the
clock of the given host has a skew of 1.3 msec per hour relative clock of the given host has a skew of 1.3 msec per hour relative
to UTC, and this threatens accuracy. We might also speak of the to UTC, which threatens accuracy. We might also speak of the
skew of one clock relative to another clock, and this threatens skew of one clock relative to another clock, which threatens
synchronization. synchronization.
3. A Singleton Definition for One-way Packet Loss 3. A Singleton Definition for One-way Packet Loss
3.1. Metric Name: 3.1. Metric Name:
Type-P-One-way-Packet-Loss Type-P-One-way-Packet-Loss
3.2. Metric Parameters: 3.2. Metric Parameters:
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for more details. for more details.
The last source of error, resource limits, cause the packet to be The last source of error, resource limits, cause the packet to be
dropped by the measurement instrument, and counted as lost when in dropped by the measurement instrument, and counted as lost when in
fact the network delivered the packet in reasonable time. fact the network delivered the packet in reasonable time.
The measurement instruments should be calibrated such that the loss The measurement instruments should be calibrated such that the loss
threshold is reasonable for application of the metrics and the clocks threshold is reasonable for application of the metrics and the clocks
are synchronized enough so the loss threshold remains reasonable. are synchronized enough so the loss threshold remains reasonable.
In addition, the instruments should be checked to ensure the In addition, the instruments should be checked to ensure the that the
probability is low that a packet arrives at the network interface, possibility a packet arrives at the network interface, but is lost
but is lost due to congestion on the interface or to other resource due to congestion on the interface or to other resource exhaustion
exhaustion (e.g., buffers) on the instrument. (e.g., buffers) on the instrument is low.
3.8. Reporting the metric: 3.8. Reporting the metric:
The calibration and context in which the metric is measured must be The calibration and context in which the metric is measured MUST be
carefully considered, and should always be reported along with metric carefully considered, and SHOULD always be reported along with metric
results. We now present four items to consider: Type-P of the test results. We now present four items to consider: Type-P of the test
packets, the loss threshold, instrument calibration, and the path packets, the loss threshold, instrument calibration, and the path
traversed by the test packets. This list is not exhaustive; any traversed by the test packets. This list is not exhaustive; any
additional information that could be useful in interpreting additional information that could be useful in interpreting
applications of the metrics should also be reported. applications of the metrics should also be reported.
3.8.1. Type-P 3.8.1. Type-P
As noted in the Framework document [1], the value of the metric may As noted in the Framework document [1], the value of the metric may
depend on the type of IP packets used to make the measurement, or depend on the type of IP packets used to make the measurement, or
"Type-P". The value of Type-P-One-way-Delay could change if the "Type-P". The value of Type-P-One-way-Delay could change if the
protocol (UDP or TCP), port number, size, or arrangement for special protocol (UDP or TCP), port number, size, or arrangement for special
treatment (e.g., IP precedence or RSVP) changes. The exact Type-P treatment (e.g., IP precedence or RSVP) changes. The exact Type-P
used to make the measurements must be accurately reported. used to make the measurements MUST be accurately reported.
3.8.2. Loss threshold 3.8.2. Loss threshold
The threshold (or methodology to distinguish) between a large finite The threshold (or methodology to distinguish) between a large finite
delay and loss should be reported. delay and loss MUST be reported.
3.8.3. Calibration results 3.8.3. Calibration results
The degree of synchronization between the Src and Dst clocks should The degree of synchronization between the Src and Dst clocks MUST be
be reported. If possible, report the probability that a test packet reported. If possible, possibility that a test packet that arrives
that arrives at the Dst network interface is reported as lost due to at the Dst network interface is reported as lost due to resource
resource exhaustion on Dst. exhaustion on Dst SHOULD be reported.
3.8.4. Path 3.8.4. Path
Finally, the path traversed by the packet should be reported, if Finally, the path traversed by the packet SHOULD be reported, if
possible. In general it is impractical to know the precise path a possible. In general it is impractical to know the precise path a
given packet takes through the network. The precise path may be given packet takes through the network. The precise path may be
known for certain Type-P on short or stable paths. If Type-P known for certain Type-P on short or stable paths. If Type-P
includes the record route (or loose-source route) option in the IP includes the record route (or loose-source route) option in the IP
header, and the path is short enough, and all routers* on the path header, and the path is short enough, and all routers* on the path
support record (or loose-source) route, then the path will be support record (or loose-source) route, then the path will be
precisely recorded. This is impractical because the route must be precisely recorded. This is impractical because the route must be
short enough, many routers do not support (or are not configured for) short enough, many routers do not support (or are not configured for)
record route, and use of this feature would often artificially worsen record route, and use of this feature would often artificially worsen
the performance observed by removing the packet from common-case the performance observed by removing the packet from common-case
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different backbone networks.} different backbone networks.}
4. A Definition for Samples of One-way Packet Loss 4. A Definition for Samples of One-way Packet Loss
Given the singleton metric Type-P-One-way-Packet-Loss, we now define Given the singleton metric Type-P-One-way-Packet-Loss, we now define
one particular sample of such singletons. The idea of the sample is one particular sample of such singletons. The idea of the sample is
to select a particular binding of the parameters Src, Dst, and Type- to select a particular binding of the parameters Src, Dst, and Type-
P, then define a sample of values of parameter T. The means for P, then define a sample of values of parameter T. The means for
defining the values of T is to select a beginning time T0, a final defining the values of T is to select a beginning time T0, a final
time Tf, and an average rate lambda, then define a pseudo-random time Tf, and an average rate lambda, then define a pseudo-random
Poisson arrival process of rate lambda, whose values fall between T0 Poisson process of rate lambda, whose values fall between T0 and Tf.
and Tf. The time interval between successive values of T will then The time interval between successive values of T will then average
average 1/lambda. 1/lambda.
{Comment: Note that Poisson sampling is only one way of defining a
sample. Poisson has the advantage of limiting bias, but other
methods of sampling might be appropriate for different situations.
We encourage others who find such appropriate cases to use this
general framework and submit their sampling method for
standardization.}
4.1. Metric Name: 4.1. Metric Name:
Type-P-One-way-Packet-Loss-Poisson-Stream Type-P-One-way-Packet-Loss-Poisson-Stream
4.2. Metric Parameters: 4.2. Metric Parameters:
+ Src, the IP address of a host + Src, the IP address of a host
+ Dst, the IP address of a host + Dst, the IP address of a host
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beginning at or before T0, with average arrival rate lambda, and beginning at or before T0, with average arrival rate lambda, and
ending at or after Tf. Those time values greater than or equal to T0 ending at or after Tf. Those time values greater than or equal to T0
and less than or equal to Tf are then selected. At each of the times and less than or equal to Tf are then selected. At each of the times
in this process, we obtain the value of Type-P-One-way-Packet-Loss at in this process, we obtain the value of Type-P-One-way-Packet-Loss at
this time. The value of the sample is the sequence made up of the this time. The value of the sample is the sequence made up of the
resulting <time, loss> pairs. If there are no such pairs, the resulting <time, loss> pairs. If there are no such pairs, the
sequence is of length zero and the sample is said to be empty. sequence is of length zero and the sample is said to be empty.
4.5. Discussion: 4.5. Discussion:
Note first that, since a pseudo-random number sequence is employed, The reader should be familiar with the in-depth discussion of Poisson
the sequence of times, and hence the value of the sample, is not sampling in the Framework document [1], which includes methods to
fully specified. Pseudo-random number generators of good quality compute and verify the pseudo-random Poisson process.
will be needed to achieve the desired qualities.
We specifically do not constrain the value of lambda, except to note
the extremes. If the rate is too large, then the measurement traffic
will perturb the network, and itself cause congestion. If the rate
is too small, then you might not capture interesting network
behavior. {Comment: We expect to document our experiences with, and
suggestions for, lambda elsewhere, culminating in a "best current
practices" document.}
Since a pseudo-random number sequence is employed, the sequence of
times, and hence the value of the sample, is not fully specified.
Pseudo-random number generators of good quality will be needed to
achieve the desired qualities.
The sample is defined in terms of a Poisson process both to avoid the The sample is defined in terms of a Poisson process both to avoid the
effects of self-synchronization and also capture a sample that is effects of self-synchronization and also capture a sample that is
statistically as unbiased as possible. {Comment: there is, of statistically as unbiased as possible. The Poisson process is used
course, no claim that real Internet traffic arrives according to a to schedule the delay measurements. The test packets will generally
Poisson arrival process. not arrive at Dst according to a Poisson distribution, since they are
influenced by the network.
{Comment: there is, of course, no claim that real Internet traffic
arrives according to a Poisson arrival process.
It is important to note that, in contrast to this metric, loss rates It is important to note that, in contrast to this metric, loss rates
observed by transport connections do not reflect unbiased samples. observed by transport connections do not reflect unbiased samples.
For example, TCP transmissions both (1) occur in bursts, which can For example, TCP transmissions both (1) occur in bursts, which can
induce loss due to the burst volume that would not otherwise have induce loss due to the burst volume that would not otherwise have
been observed, and (2) adapt their transmission rate in an attempt to been observed, and (2) adapt their transmission rate in an attempt to
minimize the loss rate observed by the connection.} minimize the loss rate observed by the connection.}
All the singleton Type-P-One-way-Packet-Loss metrics in the sequence All the singleton Type-P-One-way-Packet-Loss metrics in the sequence
will have the same values of Src, Dst, and Type-P. will have the same values of Src, Dst, and Type-P.
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packets; it is possible that the Src could send one test packet at packets; it is possible that the Src could send one test packet at
TS[i], then send a second one (later) at TS[i+1], while the Dst could TS[i], then send a second one (later) at TS[i+1], while the Dst could
receive the second test packet at TR[i+1], and then receive the first receive the second test packet at TR[i+1], and then receive the first
one (later) at TR[i]. one (later) at TR[i].
4.7. Errors and Uncertainties: 4.7. Errors and Uncertainties:
In addition to sources of errors and uncertainties associated with In addition to sources of errors and uncertainties associated with
methods employed to measure the singleton values that make up the methods employed to measure the singleton values that make up the
sample, care must be given to analyze the accuracy of the Poisson sample, care must be given to analyze the accuracy of the Poisson
arrival process of the wire-time of the sending of the test packets. arrival process of the wire-times of the sending of the test packets.
Problems with this process could be caused by several things, Problems with this process could be caused by several things,
including problems with the pseudo-random number techniques used to including problems with the pseudo-random number techniques used to
generate the Poisson arrival process. The Framework document shows generate the Poisson arrival process. The Framework document shows
how to use the Anderson-Darling test to verify the Poisson process. how to use the Anderson-Darling test verify the accuracy of the
Poisson process over small time frames. {Comment: The goal is to
ensure that the test packets are sent "close enough" to a Poisson
schedule, and avoid periodic behavior.}
4.8. Reporting the metric: 4.8. Reporting the metric:
The calibration and context for the underlying singletons should be The calibration and context for the underlying singletons MUST be
reported along with the stream. (See "Reporting the metric" for reported along with the stream. (See "Reporting the metric" for
Type-P-One-way-Packet-Loss.) Type-P-One-way-Packet-Loss.)
5. Some Statistics Definitions for One-way Packet Loss 5. Some Statistics Definitions for One-way Packet Loss
Given the sample metric Type-P-One-way-Packet-Loss-Poisson-Stream, we Given the sample metric Type-P-One-way-Packet-Loss-Poisson-Stream, we
now offer several statistics of that sample. These statistics are now offer several statistics of that sample. These statistics are
offered mostly to be illustrative of what could be done. offered mostly to be illustrative of what could be done.
5.1. Type-P-One-way-Packet-Loss-Average 5.1. Type-P-One-way-Packet-Loss-Average
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Note that, since healthy Internet paths should be operating at loss Note that, since healthy Internet paths should be operating at loss
rates below 1% (particularly if high delay-bandwidth products are to rates below 1% (particularly if high delay-bandwidth products are to
be sustained), the sample sizes needed might be larger than one would be sustained), the sample sizes needed might be larger than one would
like. Thus, for example, if one wants to discriminate between like. Thus, for example, if one wants to discriminate between
various fractions of 1% over one-minute periods, then several hundred various fractions of 1% over one-minute periods, then several hundred
samples per minute might be needed. This would result in larger samples per minute might be needed. This would result in larger
values of lambda than one would ordinarily want. values of lambda than one would ordinarily want.
Note that although the loss threshold should be set such that any Note that although the loss threshold should be set such that any
errors in loss are not significant, if the probability that a packet errors in loss are not significant, if the possibility that a packet
which arrived is counted as lost due to resource exhaustion is which arrived is counted as lost due to resource exhaustion is
significant compared to the loss rate of interest, Type-P-One-way- significant compared to the loss rate of interest, Type-P-One-way-
Packet-Loss-Average will be meaningless. Packet-Loss-Average will be meaningless.
6. Security Considerations 6. Security Considerations
Conducting Internet measurements raises both security and privacy Conducting Internet measurements raises both security and privacy
concerns. This memo does not specify an implementation of the concerns. This memo does not specify an implementation of the
metrics, so it does not directly affect the security of the Internet metrics, so it does not directly affect the security of the Internet
nor of applications which run on the Internet. However, nor of applications which run on the Internet. However,
implementations of these metrics must be mindful of security and implementations of these metrics must be mindful of security and
privacy concerns. privacy concerns.
There are two types of security concerns: potential harm caused by There are two types of security concerns: potential harm caused by
the measurements, and potential harm to the measurements. The the measurements, and potential harm to the measurements. The
measurements could cause harm because they are active, and inject measurements could cause harm because they are active, and inject
packets into the network. The measurement parameters must be packets into the network. The measurement parameters MUST be
carefully selected so that the measurements inject trivial amounts of carefully selected so that the measurements inject trivial amounts of
additional traffic into the networks they measure. If they inject additional traffic into the networks they measure. If they inject
"too much" traffic, they can skew the results of the measurement, and "too much" traffic, they can skew the results of the measurement, and
in extreme cases cause congestion and denial of service. in extreme cases cause congestion and denial of service.
The measurements themselves could be harmed by routers giving The measurements themselves could be harmed by routers giving
measurement traffic a different priority than "normal" traffic, or by measurement traffic a different priority than "normal" traffic, or by
an attacker injecting artificial measurement traffic. If routers can an attacker injecting artificial measurement traffic. If routers can
recognize measurement traffic and treat it separately, the recognize measurement traffic and treat it separately, the
measurements will not reflect actual user traffic. If an attacker measurements will not reflect actual user traffic. If an attacker
injects artificial traffic that is accepted as legitimate, the loss injects artificial traffic that is accepted as legitimate, the loss
rate will be artificially lowered. Therefore, the measurement rate will be artificially lowered. Therefore, the measurement
methodologies should include appropriate techniques to reduce the methodologies SHOULD include appropriate techniques to reduce the
probability measurement traffic can be distinguished from "normal" probability measurement traffic can be distinguished from "normal"
traffic. Authentication techniques, such as digital signatures, may traffic. Authentication techniques, such as digital signatures, may
be used where appropriate to guard against injected traffic attacks. be used where appropriate to guard against injected traffic attacks.
The privacy concerns of network measurement are limited by the active The privacy concerns of network measurement are limited by the active
measurements described in this memo. Unlike passive measurements, measurements described in this memo. Unlike passive measurements,
there can be no release of existing user data. there can be no release of existing user data.
7. Acknowledgements 7. Acknowledgements
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[2] G. Almes, S. Kalidindi, and M. Zekauskas, "A One-way Delay [2] G. Almes, S. Kalidindi, and M. Zekauskas, "A One-way Delay
Metric for IPPM", Internet-Draft <draft-ietf-ippm-delay-04.txt>, Metric for IPPM", Internet-Draft <draft-ietf-ippm-delay-04.txt>,
August 1998. August 1998.
[3] J. Mahdavi and V. Paxson, "IPPM Metrics for Measuring [3] J. Mahdavi and V. Paxson, "IPPM Metrics for Measuring
Connectivity", Internet-Draft <draft-ietf-ippm- Connectivity", Internet-Draft <draft-ietf-ippm-
connectivity-02.txt>, August 1998. connectivity-02.txt>, August 1998.
[4] J. Postel, "Internet Protocol", RFC 791, September 1981. [4] J. Postel, "Internet Protocol", RFC 791, September 1981.
[5] S. Bradner, "Key words for use in RFCs to Indicate Requirement
Levels", RFC 2119, March 1997.
9. Authors' Addresses 9. Authors' Addresses
Guy Almes Guy Almes
Advanced Network & Services, Inc. Advanced Network & Services, Inc.
200 Business Park Drive 200 Business Park Drive
Armonk, NY 10504 Armonk, NY 10504
USA USA
Phone: +1 914 765 1120 Phone: +1 914 765 1120
EMail: almes@advanced.org EMail: almes@advanced.org
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9. Authors' Addresses 9. Authors' Addresses
Guy Almes Guy Almes
Advanced Network & Services, Inc. Advanced Network & Services, Inc.
200 Business Park Drive 200 Business Park Drive
Armonk, NY 10504 Armonk, NY 10504
USA USA
Phone: +1 914 765 1120 Phone: +1 914 765 1120
EMail: almes@advanced.org EMail: almes@advanced.org
Sunil Kalidindi Sunil Kalidindi
Advanced Network & Services, Inc. Advanced Network & Services, Inc.
200 Business Park Drive 200 Business Park Drive
Armonk, NY 10504 Armonk, NY 10504
USA USA
Phone: +1 914 765 1128 Phone: +1 914 765 1128
EMail: kalidindi@advanced.org EMail: kalidindi@advanced.org
Matthew J. Zekauskas Matthew J. Zekauskas
Advanced Network & Services, Inc. Advanced Network & Services, Inc.
200 Buisiness Park Drive 200 Buisiness Park Drive
Armonk, NY 10504 Armonk, NY 10504
USA USA
Phone: +1 914 765 1112 Phone: +1 914 765 1112
EMail: matt@advanced.org EMail: matt@advanced.org
Expiration date: March, 1999 Expiration date: May, 1999
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