PSAMP working group
Internet Draft EDITOR: B. Claise
draft-ietf-psamp-protocol-01.txt Cisco Systems
Expires: August 2004 February 2004
Packet Sampling (PSAMP) Protocol Specifications
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF), its areas, and its working groups. Note that
other groups may also distribute working documents as Internet-
Drafts. Internet-Drafts are draft documents valid for a maximum of
six months and may be updated, replaced, or obsolete by other
documents at any time. It is inappropriate to use Internet-Drafts as
reference material or to cite them other than as "work in progress."
The list of current Internet-Drafts can be accessed at
http://www.ietf.org/ietf/1id-abstracts.txt
The list of Internet-Draft Shadow Directories can be accessed at
http://www.ietf.org/shadow.html.
Abstract
This document specifies the export of packet information from a
PSAMP Exporting Process to a PSAMP Colleting Process. For export of
packet information the IP Flow Information eXport (IPFIX) protocol
is used. The IPFIX protocol is well suited for this purpose, because
the IPFIX architecture matches the PSAMP architecture very well and
the means provided by the IPFIX protocol are sufficient. The
document specifies in detail how the IPFIX protocol is used for
PSAMP export of packet information.
Conventions used in this 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.
Claise, et. al Standard Track [Page 1]
PSAMP Protocol Specifications February 2004
Table of Contents
1. Open Issues..................................................2
1.1 Open Issues................................................2
1.2 Action Items...............................................3
2. Introduction.................................................3
3. Terminology..................................................4
4. Differences between PSAMP and IPFIX..........................4
4.1 Architecture Point of View.................................4
4.2 Protocol Point of View.....................................6
4.3 Information Model Point of View............................6
5. Using IPFIX for PSAMP........................................7
5.1 High Level View of the Integration.........................7
5.2 Partial or Entire IPFIX Protocol Specifications Support....7
6. PSAMP Requirements versus the IPFIX Solution.................8
6.1 IPFIX Solution for the PSAMP Requirements..................8
7. Low Level View of the Integration...........................11
7.1 Sampling Case, PSAMP Base Level of Functionality..........11
7.1.1 Example..............................................11
7.2 Sampling Case.............................................12
7.2.1 Example..............................................13
7.3 Filtering Case............................................13
7.3.1 Example..............................................13
8. Security Considerations.....................................13
9. IANA Considerations.........................................13
10. References.................................................13
10.1 Normative References.....................................13
10.2 Informative References...................................14
11. Acknowledgments............................................14
1.
Open Issues
1.1
Open Issues
This section covers the open issues, still to be resolved/updated in
this draft:
PROTO-01 Do we want to distinguish an IPFIX Flow Record export with
one packet from a PSAMP export?
PROTO-02 Need to fill in the examples section 7.1.1, 7.1.2 and 7.1.3
PROTO-03 in packet interpretation.
Options Template FlowSet (SELECTOR_ID, SAMPLING_ALGO, SAMPLING
PARAM, TIMESTAMP, OBSERVATION POINT)
The packet reports MUST contain:
- the input sequence number(s), denoted the SEQUENCE-NUMBER in
[PSAMP-INFO]
Claise, et. al Standard Track [Page 2]
PSAMP Protocol Specifications February 2004
- some number of contiguous bytes from the start of the
packet, denoted the PACKET-SAMPLE in [PSAMP-INFO]
- the destination BGP AS , denoted destinationAS in [IPFIX-
INFO]
- the input interface, denoted ingressPort in [IPFIX-INFO]
THIS IS NOT A GOOD EXAMPLE
PROTO-04 Extend security considerations by a discussion on exported
payload
1.2
Action Items
This section covers the action items for this draft
ACTION-01 For section 6 "PSAMP requirements versus the IPFIX
solution", check if there are any other requirements in the [PSAMP-
FRAMEWORK].
ACTION-02 Update the terminology section
ACTION-03 A new section about the terminology comparison between
[PSAMP-PROTO] (hence [IPFIX-PROTO]) and [PSAMP-FRAMEWORK]
- Flow Data Records sent in Data FlowSet = packet report in
[PSAMP-FRAMEWORK]
- Options Data Record sent in Data FlowSet = packet interpretation
n [PSAMP-FRAMEWORK]
Exporting Process in IPFIX = Reporting Process in [PSAMP-
FRAMEWORK]
Note1: this is somehow explained in section 5.1
ACTION-04 Should briefly discuss the fact that PSAMP is OK with
IPFIX requirements in terms of time (uSec precision)
ACTION-05 Check for the existence of the Information Elements
defined here in [PSAMP-INFO] and modify if appropriate. Example:
Selector ID, packet-sample, sampling-algorithm, hash-value, etc
For example, the section 7.1
ACTION-06 In section 6.1 An Options Templates MUST be sent on
regular basis. -> make the link with Metering Process Stats
currently discussed in the IPFIX mailing list and in [IPFIX-PROTO]
ACTION-07 Some text explanation the encoding of the new Information
Elements. For example, the packet-fragment will use the Variable
Length Data Type as described in [IPFIX-PROTO]
ACTION-08 Section 6 about PSAMP requirements: check if any changes
with the version 5 of [PSAMP-FRAMEWORK]
2.
Introduction
The IP Flow information export (IPFIX) protocol specified in [IPFIX-
PROTO] and [IPFIX-INFO] exports IP traffic information observed at
Claise, et. al Standard Track [Page 3]
PSAMP Protocol Specifications February 2004
network devices. This matches the general protocol requirements
outlined in the Packet SAMPling (PSAMP) framework [PSAMP-FMWK].
However, there are some architectural differences between IPFIX and
PSAMP and in the requirements for an export protocol. While in the
IPFIX architecture [IPFIX-ARCH] packet sampling is just one out of
many components considered, it is the focus of the PSAMP framework
[PSAMP-FMWK]. This basic difference and a set of derived differences
in protocol requirements are outlined in Section 4. Despite these
differences, the IPFIX protocol is well suited as PSAMP protocol.
Section 5 specifies how the IPFIX protocol is used for the export of
packet samples. Required extensions of the IPFIX information model
are specified in the PSAMP information model [PSAMP-INFO].
3.
Terminology
EDITORS NOTE:
- To be copied in from [PSAMP-FRAMEWORK].
- From [IPFIX-PROTO]:
- need Flow Record, Flow, Information Element, Metering Process,
Exporting Process, Collector, Scope
- need all terms from the table in section 5.2. That is:
FlowSet, Template Record, Data Record, Flow Data Record, Data
FlowSet, Options Data Record, Template FlowSet, Template
Record(s), Options Template FlowSet, Options Template Record
- need PSAMP device
- All the terms will have their initial letter in upper case
4.
Differences between PSAMP and IPFIX
The output of the IPFIX working group relevant for this draft, is
structured into three documents:
- IP Flow information architecture [IPFIX-ARCH]
- IPFIX Protocol Specifications [IPFIX-PROTO]
- IP Flow information export information model [IPFIX-INFO]
4.1
Architecture Point of View
Traffic Flow measurement as described in the IPFIX requirements
[IPFIX-REQ] and the IPFIX architecture [IPFIX-ARCH] can be separated
into two stages: packet processing and Flow processing.
The figure below illustrates these stages.
On stage 1, all processing steps act on packets. Packets are
captured, time stamped, selected by one or more selection steps and
finally forwarded to packet classification that maps packets to
Claise, et. al Standard Track [Page 4]
PSAMP Protocol Specifications February 2004
Flows. The packets selection steps may include filtering and
sampling functions.
On stage 2, all processing steps act on Flows. After packets are
classified (mapped to Flows), Flows are generated or updated if they
exist already. Flow generation and update steps may be performed
repeatedly for aggregating Flows. Finally, Flows are exported.
Packet sampling as described in the PSAMP framework [PSAMP-FMWK]
covers only stage 1 of the IPFIX architecture with the packet
classification replaced by packet record export.
IPFIX architecture PSAMP framework
packet header packet header
capturing \ capturing
| | |
timestamping | timestamping
| | |
v | v
+------>+ | stage 1: +------>+
| | > packet | |
| packet | processing | packet
| selection | | selection
| | | | |
+-------+ | +-------+
| | |
v | v
packet / packet record
classification \ export
| |
v |
+------>+ |
| | |
| Flow generation |
| and update | stage 2:
| | > Flow
| v | processing
| Flow |
| selection |
| | |
+-------+ |
| |
v |
Flow Record /
export
Claise, et. al Standard Track [Page 5]
PSAMP Protocol Specifications February 2004
Comparison of IPFIX architecture and PSAMP framework
4.2
Protocol Point of View
Concerning the protocol, the major difference between IPFIX and
PSAMP is that the IPFIX protocol exports Flow Records while the
PSAMP protocol exports packet records. From a pure export point of
view, IPFIX will not distinguish a Flow Record composed of several
packets aggregated together, from a Flow Record composed of a single
packet. So the PSAMP export can be seen as special IPFIX Flow Record
containing information about a single packet.
EDITORS NOTE: maybe we want to distinguish an IPFIX Flow Record
export with one packet from a PSAMP export?
Extensions of the IPFIX protocol needed by PSAMP are rather limited.
A basic one is the need of a data type for protocol fields that has
flexible length, such as an octet array. This is needed by the PSAMP
protocol for reporting content of captured packets, for example the
first 40 octets of a packet.
4.3
Information Model Point of View
However, the overlap between both protocols is still quite large.
Most of the data fields in the IPFIX protocol also apply to PSAMP,
for example all fields reporting packet header fields. Only a few
fields, such as flowCount, packetCount (whose value will always be
one) etc., cannot be used in a meaningful way by the PSAMP protocol.
Also, IPFIX protocol requirements concerning stage 2 do not apply to
the PSAMP protocol.
Further required extensions apply to the information model. The
IPFIX information model is rather poor concerning sampling. Just two
fields, one for the sampling method and one for the sampling rate,
are not sufficient, as shown in [PSAMP-SLCT]. A set of several
additional fields is required for satisfying the requirements for a
PSAMP information model. Additional required extensions of the
information model concern packet filtering, and the a field
reporting content of a packet using the flexible length data type
mentioned above.
Claise, et. al Standard Track [Page 6]
PSAMP Protocol Specifications February 2004
Exploiting the extensibility of the IPFIX information model, the
required extension is covered by the PSAMP information model
specified in [PSAMP-INFO].
5.
Using IPFIX for PSAMP
5.1
High Level View of the Integration
The Template Record in the Template FlowSet is used to describe the
different PSAMP Information Elements that will be exported to the
Collector. The Collector decodes the Template FlowSet and knows
which Information Elements to expect when it receives the Flow Data
Records in the Data FlowSet, i.e. the PSAMP Packet Reports.
Typically, in the base level of the PSAMP functionality, the
Template FlowSet will contain the input sequence number, the packet
fragment (some number of contiguous bytes from the start of the
packet) and the selector ID.
The Options Template Record in the Options Template FlowSet is used
to describe the different PSAMP Information Elements that concern
the Metering Process itself: sampling and/or filtering functions,
plus the associated parameters. The Collector decodes the Options
Template FlowSet and knows which Information Elements to expect when
it receives the Options Data Records in the Data FlowSet, i.e. the
PSAMP Report Interpretation. Typically, the Options Template would
contain the Selector ID, the sampling or filtering functions, and
the sampling or filtering associated parameters.
5.2
Partial or Entire IPFIX Protocol Specifications Support
The "High level view of the integration" section 5.1 concludes that
PSAMP requires all the different possibilities of the IPFIX protocol
specifications [IPFIX-PROTO]. That is the 3 types of FlowSet (Data
FlowSet, Template FlowSet and Options Templates FlowSet), the 2
types of Templates Records (Template Record and Options Template
Record), and the 2 types of Data Record (Flow Data Record, Options
Data Record), as described again in the table below.
+------------------+---------------------------------------------+
| | Contents |
| +--------------------+------------------------+
| FlowSet | Template Record | Data Record |
+------------------+--------------------+------------------------+
| | | Flow Data Record(s) |
Claise, et. al Standard Track [Page 7]
PSAMP Protocol Specifications February 2004
| Data FlowSet | / | or |
| | | Options Data Record(s) |
+------------------+--------------------+------------------------+
| Template FlowSet | Template Record(s) | / |
+------------------+--------------------+------------------------+
| Options Template | Options Template | / |
| FlowSet | Record(s) | |
+------------------+--------------------+------------------------+
As a consequence, PSAMP can't rely on a subset of the IPFIX protocol
specifications are described in [IPFIX-PROTO]. The entire IPFIX
protocol specifications MUST be implemented for the PSAMP export.
6.
PSAMP Requirements versus the IPFIX Solution
[PSAMP-FRAMEWORK] describes some requirements that affect directly
the export protocol. Refer to the following sections:
section 3.2 "Reporting Process Requirements"
section 3.3 "Exporting Process Requirements"
section 5 "Reporting Process"
[PSAMP-FRAMEWORK] also describes in the section 3.1 one requirement
that, if not directly related to the export protocol, will put some
constraints on it:
Selection Process Requirements:
- Parallel Measurements: multiple independent measurement
processes at the same entity."
[PSAMP-FRAMEWORK] finally describes in the section 5 some
requirements regarding the reporting process. This series of
requirements specifies the different Information Elements that MUST
and SHOULD reported to the collector. Nevertheless IPFIX, being a
generic export protocol, can export any Information Elements as long
as there are described in the information model. So these
requirements are mainly targeted for the [PSAMP-INFO] document.
6.1
IPFIX Solution for the PSAMP Requirements
Let's address the PSAMP requirements one by one.
* Parallel Measurements: multiple independent measurement processes
at the same entity. Refer to [PSAMP-FRAMEWORK] section 3.1 "Selection
Process Requirements".
Claise, et. al Standard Track [Page 8]
PSAMP Protocol Specifications February 2004
This requirement is addressed by exporting the Selector ID
Information Element in every packet report, so part of every Flow
Data Records. Note that without this requirement, exporting the Scope
part of every single packet report could have been sufficient.
* Transparency: allow transparent interpretation of measurements as
communicated by PSAMP reporting, without any need to obtain
additional information concerning the observed packet stream. Refer
to [PSAMP-FRAMEWORK] section 3.2 "Reporting Process Requirements".
This requirement is addressed by exporting the Selector ID
Information Element in every Flow Data Records (packet report) and
exporting the associated SAMPLING_ALGORITHM and SAMPLING PARAMETERS
Information Elements in the Options Data Record (packet
interpretation). So the all the Metering Process parameters are
linked to the Flow Data Records.
* Robustness to Information Loss: allow robust interpretation of
measurements with respect to reports missing due to data loss, e.g.
in transport, or within the measurement, reporting or Exporting
Processes. Inclusion in reporting of information that enables the
accuracy of measurements to be determined. Refer to [PSAMP-FRAMEWORK]
section 3.2 "Reporting Process Requirements".
An Options Templates MUST be sent on regular basis. This Options
Template contains for example the total number of packet report
exported from the PSAMP device, the total number of packet observed,
etc... Thus the Collector can compare the number of packet report
received per selector ID with the number actually metered and/or
sent. In case of discrepancy, a new sampling rate could be computed.
* Faithfulness: all reported quantities that relate to the packet
treatment MUST reflect the router state and configuration encountered
by the packet at the time it is received by the measurement process.
Refer to [PSAMP-FRAMEWORK] section 3.2 "Reporting Process
Requirements".
This requirement doesn't concern the export protocol itself but the
Metering Process, even if described in the "Reporting Process
Requirements" section.
Claise, et. al Standard Track [Page 9]
PSAMP Protocol Specifications February 2004
* Privacy: selection of the content of packet reports will be
cognizant of privacy and anonymity issues while being responsive to
the needs of measurement applications, and in accordance with RFC
2804. Full packet capture of arbitrary packet streams is explicitly
out of scope. Refer to [PSAMP-FRAMEWORK] section 3.2 "Reporting
Process Requirements".
This requirement doesn't concern the export protocol itself, even if
described in the "Reporting Process Requirements" section.
* Timeliness: reports on selected packets MUST be made available to
the collector quickly enough to support near real time applications.
Specifically, any report on a packet MUST be dispatched within 1
second of the time of receipt of the packet by the measurement
process. Refer to [PSAMP-FRAMEWORK] section 3.3 "Export Process
Requirements".
The IPFIX protocol specifications [IPFIX-PROTO] describe an
inactivity timeout for the Flow expiration. This inactivity timeout
is configurable, with a minimum value of 0 for immediate expiration.
Note that this minimum value of 0 will force every single Flow Data
Record to contain information about a single packet and not an
aggregation of packets.
* Congestion Avoidance: export of a report stream across a network
MUST be congestion avoiding in compliance with RFC 2914. Refer to
[PSAMP-FRAMEWORK] section 3.3 "Export Process Requirements".
IPFIX, by its charter, MUST also respect this requirement.
* Secure Export:
- confidentiality: the option to encrypt exported data MUST be
provided.
- integrity: alterations in transit to exported data MUST be
detectable at the collector
- authenticity: authenticity of exported data MUST be verifiable
by the collector in order to detect forged data.
The motivation here is the same as for security in IPFIX export.
Refer to [PSAMP-FRAMEWORK] section 3.3 "Export Process
Requirements".
Claise, et. al Standard Track [Page 10]
PSAMP Protocol Specifications February 2004
7.
Low Level View of the Integration
7.1
Sampling Case, PSAMP Base Level of Functionality
EDITORS NOTE: LET'S ASSUME THAT THE [PSAMP-INFO] DEFINES THE
FOLLOWING DATA TYPES
SEQUENCE-NUMBER: the input sequence number,
PACKET-SAMPLE: some number of contiguous bytes from the start
of the packet
SELECTOR-ID:
SAMPLING-ALGORITHM:
SAMPLING-PARAMETER1, SAMPLING-PARAMETERS2, ETC...
As described in the section 5.1 "Mandatory Contents of Packet
Reports" of [PSAMP-FRAMEWORK], the packet reports must contain:
- the input sequence number(s), denoted the SEQUENCE-NUMBER in
[PSAMP-INFO]
- some number of contiguous bytes from the start of the packet,
denoted the PACKET-SAMPLE in [PSAMP-INFO].
Thus the Template FlowSet defines a Template Record composed of
SEQUENCE-NUMBER, PACKET-SAMPLE and SELECTOR-ID.
The report interpretation must contain:
- the sampling algorithm, denoted SAMPLING-ALGORITHM in [PSAMP-INFO]
- the sampling parameters denoted SAMPLING-PARAMETER1, SAMPLING-
PARAMETER2, etc... in [PSAMP-INFO]
The Options Template FlowSet defines a Options Template Record
composed of SELECTOR-ID, SAMPLING-ALGORITHM, SAMPLING-PARAMETERS.
Finally the Data FlowSet is used to export the Flow Data Record(s)
containing the real values of SEQUENCE-NUMBER, PACKET-SAMPLE and
SELECTOR-ID. The Data FlowSet is also used to export the Options
Data Record(s) containing the real values of SELECTOR-ID, SAMPLING-
ALGORITHM, SAMPLING-PARAMETERS.
By means of the SELECTOR-ID, the Collector can link any Flow Data
Record to the corresponding Options Data Record. That is, any Flow
Data Record to the Metering Process function and parameters.
7.1.1 Example
EDITORS THIS MUST BE A FULL EXAMPLE LIKE IN SECTION 13 OF [IPFIX-
PROTO].
THE [PSAMP-INFO] MUST BE FIRST PUBLISHED.
Claise, et. al Standard Track [Page 11]
PSAMP Protocol Specifications February 2004
7.2
Sampling Case
The PSAMP reporting process SHOULD also report fields relating to
the protocols used in the packets, to the packet treatment and to
the selection state associated with the packet, as specified in
[PSAMP-FRAMEWORK] section 5.2 "Recommended Contents for Packet
Reports".
Let's take the same example as in the section 7.1, but let's add the
export of the destination BGP Autonomous System (AS) [1771] and of
the input interface
The packet reports MUST contain:
- the input sequence number(s), denoted the SEQUENCE-NUMBER in
[PSAMP-INFO]
- some number of contiguous bytes from the start of the packet,
denoted the PACKET-SAMPLE in [PSAMP-INFO]
- the destination BGP AS , denoted destinationAS in [IPFIX-INFO]
- the input interface, denoted ingressPort in [IPFIX-INFO]
Thus the Template FlowSet defines a Template Record composed of
SEQUENCE-NUMBER, PACKET-SAMPLE and SELECTOR-ID, destinationAS and
ingressPort.
The report interpretation will remain unchanged and must contain:
- the sampling algorithm, denoted SAMPLING-ALGORITHM in [PSAMP-INFO]
- the sampling parameters denoted SAMPLING-PARAMETER1, SAMPLING-
PARAMETER2, etc... in [PSAMP-INFO]
The Options Template FlowSet is used to define this template
composed of SELECTOR-ID, SAMPLING-ALGORITHM, SAMPLING-PARAMETERS.
Finally Data FlowSet is used to export the Flow Data Record(s)
containing the real values of SEQUENCE-NUMBER, PACKET-SAMPLE and
SELECTOR-ID, destinationAS and ingressPort. The Data FlowSet is also
used to export the Options Data Record(s) containing the real values
of SELECTOR-ID, SAMPLING-ALGORITHM, SAMPLING-PARAMETERS.
As a consequence, the collector can link any Flow Data Record to the
sampling algorithm and sampling parameters, by means of the
SELECTOR-ID value.
Claise, et. al Standard Track [Page 12]
PSAMP Protocol Specifications February 2004
7.2.1 Example
EDITORS NOTE: THIS MUST BE A FULL EXAMPLE LIKE IN SECTION 13 OF
[IPFIX-PROTO]. THE [PSAMP-INFO] MUST BE FIRST PUBLISHED.
7.3
Filtering Case
EDITORS NOTE: ACTUALLY THE EXAMPLE WILL BE QUITE SIMILAR TO 7.1 AND
7.2 BUT WILL DEPEND A LOT ON HOW WE WILL DEFINE THE FILTERING IN
[IPFIX-INFO].
7.3.1 Example
EDITORS NOTE: THIS MUST BE A FULL EXAMPLE LIKE IN SECTION 13 OF
[IPFIX-PROTO]. THE [PSAMP-INFO] MUST BE FIRST PUBLISHED.
8.
Security Considerations
As IPFIX has been selected as the PSAMP export protocol and as the
PSAMP security requirements are not stricter than the IPFIX security
requirements, refer to the IPFIX export protocol [IPFIX-PROTO] for
the security considerations.
9.
IANA Considerations
The only IANA considerations in this document concerns the extension
of Information Elements, FlowSet ID and Scope. Refer to the IANA
considerations section in [IPFIX-PROTO] where those possible new
assignments are specified.
10.
References
10.1
Normative References
[PSAMP-SAMPLE-TECH] T. Zseby, M. Molina, F. Raspall, N. Duffield
"Sampling and Filtering Techniques for IP Packet Selection" draft-
ietf-psamp-sample-tech-01.txt
[PSAMP-MIB] T. Dietz, D. Romascanu, B. Claise "Definitions of
Managed Objects for Packet Sampling" draft-ietf-psamp-mib-01.txt
Claise, et. al Standard Track [Page 13]
PSAMP Protocol Specifications February 2004
[PSAMP-INFO] T. Dietz, F. Dressler, G. Carle, B. Claise,
"Information Model for Packet Sampling Exports", draft-ietf-psamp-
info-00.txt
[IPFIX-ARCH] G. Sadasivan, N. Brownlee "Architecture Model for IP
Flow Information Export" draft-ietf-ipfix-arch-02.txt", June 2003
[IPFIX-INFO] P. Calato, J. Meyer, J. Quittek, "Information Model for
IP Flow Information Export" draft-ietf-ipfix-info-02, August 2003
[IPFIX-PROTO] B. Claise, M. Fullmer, P. Calato, R. Penno, "IPFIX
Protocol Specifications", draft-ietf-ipfix-protocol-02.txt, June
2003
[RFC1771] Y. Rekhter, T. Li, "A Border Gateway Protocol 4 (BGP-
4)", RFC 1771, March 1995.
10.2
Informative References
[PSAMP-FRAMEWORK] N. Duffield, D. Chiou, B. Claise, A. Greenber, M.
Grossglauser "A Framework for Passive Packet Measurement" draft-
ietf-psamp-framework-04.txt
[IPFIX-REQ] J. Quittek, T. Zseby, B. Claise, S. Zander,
"Requirements for IP Flow Information Export" draft-ietf-ipfix-reqs-
10.txt, June 2003
11.
Acknowledgments
To be completed.
Authors Addresses
Benoit Claise
Cisco Systems
De Kleetlaan 6a b1
1831 Diegem
Belgium
Phone: +32 2 704 5622
E-mail: bclaise@cisco.com
Juergen Quittek
NEC Europe Ltd.
Network Laboratories
Claise, et. al Standard Track [Page 14]
PSAMP Protocol Specifications February 2004
Kurfuersten-Anlage 36
69115 Heidelberg
Germany
Phone: +49 6221 90511-15
Email: quittek@ccrle.nec.de
Claise, et. al Standard Track [Page 15]
