wdiff draft-ietf-ippm-more-twamp-00.txt draft-ietf-ippm-more-twamp-01.txt

Network Working Group A. Morton
Internet-Draft AT&T Labs
Updates: 5357 (if approved) K. Hedayat
Intended status: Standards Track K. Hedayat EXFO
Expires: April 22, November 6, 2009 May 5, 2009 Brix Networks
October 19, 2008

More Features for the Two-Way Active Measurement Protocol - TWAMP
draft-ietf-ippm-more-twamp-00
draft-ietf-ippm-more-twamp-01

Status of this Memo

By submitting this Internet-Draft, each author represents that any
applicable patent or other IPR claims

This Internet-Draft is submitted to IETF in full conformance with the
provisions of which he BCP 78 and BCP 79. This document may contain material
from IETF Documents or she is aware
have been IETF Contributions published or will made publicly
available before November 10, 2008. The person(s) controlling the
copyright in some of this material may not have granted the IETF
Trust the right to allow modifications of such material outside the
IETF Standards Process. Without obtaining an adequate license from
the person(s) controlling the copyright in such materials, this
document may not be disclosed, modified outside the IETF Standards Process, and any
derivative works of which he or she becomes
aware will it may not be disclosed, in accordance with Section 6 of BCP 79. created outside the IETF Standards
Process, except to format it for publication as an RFC or to
translate it into languages other than English.

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 obsoleted 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.

This Internet-Draft will expire on April 22, November 6, 2009.

Abstract

The

This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents in effect on TWAMP - the Two-Way Active
Measurement Protocol. date of
publication of this document (http://trustee.ietf.org/license-info).
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document.

Abstract

This memo describes a simple extension to
TWAMP, TWAMP - the Two-Way Active
Measurement Protocol. The extension adds the option to use different
security modes in the TWAMP-
Control TWAMP-Control and TWAMP-Test protocols. protocols
simultaneously. The memo also requests that IANA establish a
registry for additional new features, called the TWAMP-Modes
registry.

Requirements Language

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 [RFC2119].

Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 4
2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . 3 4
3. TWAMP Control Extensions . . . . . . . . . . . . . . . . . . . 3 4
3.1. Extended Control Connection Setup . . . . . . . . . . . . . . . . . 4 5
4. Extended TWAMP Test . . . . . . . . . . . . . . . . . . . . . . 5 6
4.1. Sender Behavior . . . . . . . . . . . . . . . . . . . . . . 5 7
4.1.1. Packet Timings . . . . . . . . . . . . . . . . . . . . 5 7
4.1.2. Packet Format and Content . . . . . . . . . . . . . . . 5 7
4.2. Reflector Behavior . . . . . . . . . . . . . . . . . . . . 6 7
5. Security Considerations . . . . . . . . . . . . . . . . . . . . 6 7
6. IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 6 8
6.1. Registry Specification . . . . . . . . . . . . . . . . . . 6 8
6.2. Registry Management . . . . . . . . . . . . . . . . . . . . 6 8
6.3. Experimental Numbers . . . . . . . . . . . . . . . . . . . 7 8
6.4. Initial Registry Contents . . . . . . . . . . . . . . . . . 7 8
7. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 7 9
8. Normative References . . . . . . . . . . . . . . . . . . . . . . . . . . 7
8.1. Normative References . . . . . . . . . . . . . 9
Authors' Addresses . . . . . . 7
8.2. Informative References . . . . . . . . . . . . . . . . . . 8
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 8
Intellectual Property and Copyright Statements . . . . . . . . . . 9

1. Introduction

The IETF has completed its work on the core specification of TWAMP -
the Two-Way Active Measurement Protocol [RFC5357]. Protocol, TWAMP [RFC5357] is an
extension of the One-way Active Measurement Protocol, OWAMP
[RFC4656]. The TWAMP specification gathered wide review as it
approached completion, and the by-products were several
recommendations for new features in TWAMP. There are a growing
number TWAMP implementations at present, and wide-spread usage is
expected. There are even devices that are designed to test
implementations for protocol compliance.

This memo describes a simple extension for TWAMP, the option to use
different security modes in the TWAMP-Control and TWAMP-Test
protocols.

The relationship between this memo
protocols (mixed security mode). It also requests that IANA
establish a registry for additional new features, called the TWAMP-
Modes registry.

When the Server and TWAMP is intended Control-Client have agreed to be an
update use the mixed
security mode during control connection setup, then the Control-
Client, the Server, the Session-Sender and the Session-Reflector MUST
all conform to [RFC5357] when published. the requirements of this mode as described in sections
3, 4, and 5.

This memo updates [RFC5357].

2. Purpose and Scope

The purpose of this memo is to describe and specify an extension for
TWAMP [RFC5357]. The features [RFC5357], and extensions were vetted before
adoption in this memo. request the establishment of a registry for
future TWAMP extensions.

The scope of the memo is limited to specifications of the following:

o Extension of the modes of operation through assignment of one new
value in the Mode field (see section 3.1 of [RFC4656]), while
retaining backward compatibility with TWAMP [RFC5357]
implementations. This value adds the OPTIONAL ability to use
different security modes in the TWAMP-Control and TWAMP-Test
protocols. The motivation for this extension is to permit the low
packet rate TWAMP-Control protocol to utilize a stronger mode of
integrity protection than that used in the TWAMP-Test protocol.

3. TWAMP Control Extensions

TWAMP-Control protocol is a derivative of the OWAMP-Control protocol,
and coordinates a two-way measurement capability. All TWAMP Control
messages are similar in format and follow similar guidelines to those
defined in section 3 of [RFC4656] with the exceptions described in
TWAMP [RFC5357], and in the following sections.

All OWAMP-Control messages apply to TWAMP-Control, except for the
Fetch Session command.

3.1. Extended Control Connection Setup

TWAMP

TWAMP-Control connection establishment follows the same procedure
defined in section 3.1 of [RFC4656]. This extended mode assigns one
new bit position (and value) to allow the Test protocol security mode
to operate in Unauthenticated mode, while the Control protocol
operates in Encrypted mode. With this extension, the complete set of
TWAMP Mode values are as follows:

Value Description Reference/Explanation
0 Reserved
1 Unauthenticated RFC4656, Section 3.1
2 Authenticated RFC4656, Section 3.1
4 Encrypted RFC4656, Section 3.1
8 Unauth. TEST protocol, new bit position (3)
Encrypted CONTROL

In the original OWAMP and TWAMP Modes field, setting bit positions position 0,
1 or 2 indicated the security mode of the Control protocol, and the
Test protocol inherited the same mode (see section 4 of [RFC4656]).

In this extension to TWAMP, setting when the Control-Client sets Modes Field
bit position 3 3, it SHALL discontinue the inheritance of the security
mode in the Test protocol, and each protocol's mode SHALL be as
specified below. When the desired TWAMP Test TWAMP-Test protocol mode is
identical to the Control Session mode, the corresponding Modes Field
bit (position 0, 1 or 2) SHALL be set. set by the Control-Client. The
table below gives the various combinations of integrity protection
that are permissible in TWAMP (with this extension). The Test protocol TWAMP-
Control and TWAMP-Test protocols SHALL use the mode in each column
corresponding to the Modes Field bit position. position set in the Modes Field.

--------------------------------------------------------
Protocol | Permissible Mode Combinations (Modes bit set)
--------------------------------------------------------
Control | Unauth.(0)| Auth. == Encrypted (1,2,3)
--------------------------------------------------------
| Unauth.(0)| Unauth. (3)
-----------------------------------------------
Test | | Auth.(1)
-----------------------------------------------
| | Encrypted (2)
--------------------------------------------------------

Note that the TWAMP-Control protocol security measures are identical
in the Authenticated and Encrypted Modes. Therefore, only one new
bit position (3) is needed to convey the single mixed security mode.

The value of the Modes Field sent by the Server in the Server-
Greeting message is the bit-wise OR of the modes (bit positions) that
it is willing to support during this session. Thus, the last four
bits of the Modes 32-bit Field are used. The When no other features are
activated, the first 28 bits MUST be zero. A client conforming to
this extension of [RFC5357] MAY ignore the values in the first 28
bits of the Modes Field, or it MAY support other features that are
communicated in these bit positions.

Other ways in which TWAMP extends OWAMP are described in [RFC5357].

4. Extended TWAMP Test

The TWAMP test protocol is similar to the OWAMP [RFC4656] test
protocol with the exception that the Session-Reflector transmits test
packets to the Session-Sender in response to each test packet it
receives. TWAMP [RFC5357] defines two different test packet formats,
one for packets transmitted by the Session-Sender and one for packets
transmitted by the Session-Reflector. As with OWAMP-Test protocol
there are three security modes: modes that also determine the test packet
format: unauthenticated, authenticated, and encrypted. This TWAMP
extension makes it possible to use TWAMP-Test Unauthenticated mode
regardless of the mode used in the TWAMP-Control protocol.

This section describes OPTIONAL extensions. When the Server has
identified the ability to support the mixed security mode, the
Control-Client has selected the mixed security mode in its Set-Up-
Response, and the Server responds with a zero Accept field in the
Server-Start message, then these extensions are conditionally
REQUIRED.

4.1. Sender Behavior

This section describes REQUIRED extensions to the behavior of the TWAMP Sender.
Session-Sender.

4.1.1. Packet Timings

The Send Schedule is not utilized in TWAMP, and there are no
extensions defined in this memo.

4.1.2. Packet Format and Content

The Session Sender Session-Sender packet format and content MUST follow the same
procedure and guidelines as defined in section 4.1.2 of [RFC4656] and
section 4.1.2 of [RFC5357], with the following exceptions:

o the Send Schedule is not used, and

o the Sessions-Sender Session-Sender MUST support the mixed security mode
(Unauthenticated TEST, Encrypted CONTROL,value 8, bit position 3)
defined in section 3.1 of this memo.

4.2. Reflector Behavior

The TWAMP Reflector Session-Reflector is REQUIRED to follow the procedures and
guidelines in section 4.2 of [RFC5357], with the following
extensions:

o the Sessions-Reflector Session-Reflector MUST support the mixed security mode
(Unauthenticated TEST, Encrypted CONTROL,value 8, bit position 3)
defined in section 3.1 of this memo.

5. Security Considerations

The extended mixed-mode of operation permits stronger security/
integrity protection on the TWAMP-Control protocol while
simultaneously emphasizing accuracy or efficiency on the TWAMP-Test
protocol, thus making it possible to increase overall security when
compared to the previous options.

The security considerations that apply to any active measurement of
live networks are relevant here as well. See [RFC4656] and
[RFC5357].

6. IANA Considerations

This memo adds three one security mode combinations to bit position/value beyond those in
the OWAMP-Control specification[RFC4656], and describes behavior when
the new modes are mode is used. This memo requests creation of an IANA
registry for the TWAMP
Mode Modes field. This field is a recognized
extension mechanism for TWAMP.

6.1. Registry Specification

IANA is requested to create a TWAMP-Modes registry. TWAMP-Modes are
specified in TWAMP Server Greeting messages and Set-up Response
messages consistent with section 3.1 of [RFC4656], [RFC4656] and section 3.1 of
[RFC5357], and extended by this memo. Modes are indicated by setting
bits in the 32-bit Modes Field. Thus, this registry can contain a
total of 32 possible bit positions and corresponding values.

6.2. Registry Management

Because the TWAMP-Modes registry can contain only thirty-two values,
and because TWAMP is an IETF protocol, this registry must be updated
only by "IETF Consensus" as specified in [RFC2434](an [RFC5226](an RFC documenting
registry use that is approved by the IESG). For the Modes TWAMP-Modes
registry, we expect that new features will be assigned using
monotonically increasing bit positions and in the range [0-31] and
the corresponding values, unless there is a good reason to do
otherwise.

6.3. Experimental Numbers

No experimental values are currently assigned for the Modes Registry.

6.4. Initial Registry Contents

TWAMP Modes Registry
Value Description Semantics Definition
0 Reserved

1 Unauthenticated RFC4656, Section 3.1

2 Authenticated RFC4656, Section 3.1

4 Encrypted RFC4656, Section 3.1

8 Unauth. TEST protocol, this document, Section 3.1
Encrypted CONTROL

7. Acknowledgements

The authors would like to thank Len Ciavattone for helpful review and
comments.

8. References

8.1. Normative References

[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.

[RFC2434] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 2434,
October 1998.

[RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and M.
Zekauskas, "A One-way Active Measurement Protocol
(OWAMP)", RFC 4656, September 2006.

[RFC5226] Narten, T. and H. Alvestrand, "Guidelines for Writing an
IANA Considerations Section in RFCs", BCP 26, RFC 5226,
May 2008.

[RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and J.
Babiarz, "A Two-Way Active Measurement Protocol (TWAMP)",
RFC 5357, October 2008.

8.2. Informative References

[x] "".

Authors' Addresses

Al Morton
AT&T Labs
200 Laurel Avenue South
Middletown,, NJ 07748
USA

Phone: +1 732 420 1571
Fax: +1 732 368 1192
Email: acmorton@att.com
URI: http://home.comcast.net/~acmacm/

Kaynam Hedayat
Brix Networks
EXFO
285 Mill Road
Chelmsford, MA 01824
USA

Phone: +1
Fax: +1
Email: khedayat@brixnet.com khedayat@exfo.com
URI: http://www.brixnet.com/

Full Copyright Statement

This document is subject to the rights, licenses and restrictions
contained in BCP 78, and except as set forth therein, the authors
retain all their rights.

This document and the information contained herein are provided on an
"AS IS" basis and THE CONTRIBUTOR, THE ORGANIZATION HE/SHE REPRESENTS
OR IS SPONSORED BY (IF ANY), THE INTERNET SOCIETY, THE IETF TRUST AND
THE INTERNET ENGINEERING TASK FORCE DISCLAIM 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.

Intellectual Property

The IETF takes no position regarding the validity or scope of any
Intellectual Property Rights 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; nor does it represent that it has
made any independent effort to identify any such rights. Information
on the procedures with respect to rights in RFC documents can be
found in BCP 78 and BCP 79.

Copies of IPR disclosures made to the IETF Secretariat 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 implementers or users of this
specification can be obtained from the IETF on-line IPR repository at
http://www.ietf.org/ipr.

The IETF invites any interested party to bring to its attention any
copyrights, patents or patent applications, or other proprietary
rights that may cover technology that may be required to implement
this standard. Please address the information to the IETF at
ietf-ipr@ietf.org. http://www.exfo.com/