draft-ietf-ippm-twamp-reflect-octets-00.txt   draft-ietf-ippm-twamp-reflect-octets-01.txt 
Network Working Group A. Morton Network Working Group A. Morton
Internet-Draft L. Ciavattone Internet-Draft L. Ciavattone
Intended status: Standards Track AT&T Labs Intended status: Standards Track AT&T Labs
Expires: April 29, 2009 October 26, 2008 Expires: September 7, 2009 March 6, 2009
TWAMP Reflect Octets Feature TWAMP Reflect Octets Feature
draft-ietf-ippm-twamp-reflect-octets-00 draft-ietf-ippm-twamp-reflect-octets-01
Status of this Memo Status of this Memo
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Abstract Abstract
The IETF has completed its work on the core specification of TWAMP - The IETF has completed its work on the core specification of TWAMP -
the Two-Way Active Measurement Protocol. This memo describes a new the Two-Way Active Measurement Protocol. This memo describes a new
feature for TWAMP: an optional capability where the responder host feature for TWAMP: an optional capability where the responder host
returns some of the command octets or padding octets to the returns some of the command octets or padding octets to the
controller, and/or ensures that the same test packet sizes are used controller, and/or ensures that the same test packet sizes are used
in both directions. in both directions.
Requirements Language Requirements Language
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [RFC2119]. document are to be interpreted as described in RFC 2119 [RFC2119].
Table of Contents Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 3 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . 4
2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . 3 2. Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . 4
3. TWAMP Control Extensions . . . . . . . . . . . . . . . . . . . 4 3. TWAMP Control Extensions . . . . . . . . . . . . . . . . . . . 5
3.1. Connection Setup with Reflect Padding Feature . . . . . . 4 3.1. Connection Setup with Reflect Padding Feature . . . . . . 5
3.2. Request-TW-Session Packet Format . . . . . . . . . . . . . 5 3.2. Request-TW-Session Packet Format . . . . . . . . . . . . . 6
3.3. Accept Session Packet Format . . . . . . . . . . . . . . . 7 3.3. Accept Session Packet Format . . . . . . . . . . . . . . . 8
3.4. Additional considerations . . . . . . . . . . . . . . . . 7 3.4. Additional considerations . . . . . . . . . . . . . . . . 8
4. Extended TWAMP Test . . . . . . . . . . . . . . . . . . . . . 8 4. Extended TWAMP Test . . . . . . . . . . . . . . . . . . . . . 9
4.1. Sender Behavior . . . . . . . . . . . . . . . . . . . . . 8 4.1. Sender Behavior . . . . . . . . . . . . . . . . . . . . . 9
4.1.1. Packet Timings . . . . . . . . . . . . . . . . . . . . 8 4.1.1. Packet Timings . . . . . . . . . . . . . . . . . . . . 9
4.1.2. Packet Formats and Contents . . . . . . . . . . . . . 8 4.1.2. Packet Formats and Contents . . . . . . . . . . . . . 9
4.1.3. Padding Truncation . . . . . . . . . . . . . . . . . . 9 4.1.3. Padding Truncation . . . . . . . . . . . . . . . . . . 11
4.2. Reflector Behavior . . . . . . . . . . . . . . . . . . . . 10 4.2. Reflector Behavior . . . . . . . . . . . . . . . . . . . . 11
4.2.1. Packet Format and Contents . . . . . . . . . . . . . . 10 4.2.1. Packet Format and Contents . . . . . . . . . . . . . . 11
4.2.2. Padding Truncation . . . . . . . . . . . . . . . . . . 11 4.2.2. Padding Truncation . . . . . . . . . . . . . . . . . . 12
5. Possible Alternative . . . . . . . . . . . . . . . . . . . . . 12 5. Possible Alternative . . . . . . . . . . . . . . . . . . . . . 13
6. Security Considerations . . . . . . . . . . . . . . . . . . . 14 6. Security Considerations . . . . . . . . . . . . . . . . . . . 15
7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 14 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 15
7.1. Registry Specification . . . . . . . . . . . . . . . . . . 15 7.1. Registry Specification . . . . . . . . . . . . . . . . . . 16
7.2. Registry Management . . . . . . . . . . . . . . . . . . . 15 7.2. Registry Management . . . . . . . . . . . . . . . . . . . 16
7.3. Experimental Numbers . . . . . . . . . . . . . . . . . . . 15 7.3. Experimental Numbers . . . . . . . . . . . . . . . . . . . 16
7.4. Registry Contents . . . . . . . . . . . . . . . . . . . . 15 7.4. Registry Contents . . . . . . . . . . . . . . . . . . . . 16
8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 16 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . 17
9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 16 9. References . . . . . . . . . . . . . . . . . . . . . . . . . . 17
9.1. Normative References . . . . . . . . . . . . . . . . . . . 16 9.1. Normative References . . . . . . . . . . . . . . . . . . . 17
9.2. Informative References . . . . . . . . . . . . . . . . . . 16 9.2. Informative References . . . . . . . . . . . . . . . . . . 17
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 16 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . . 17
Intellectual Property and Copyright Statements . . . . . . . . . . 18
1. Introduction 1. Introduction
The IETF has completed its work on the core specification of TWAMP - The IETF has completed its work on the core specification of TWAMP -
the Two-Way Active Measurement Protocol [RFC5357]. TWAMP is an the Two-Way Active Measurement Protocol [RFC5357]. TWAMP is an
extension of the One-way Active Measurement Protocol, OWAMP extension of the One-way Active Measurement Protocol, OWAMP
[RFC4656]. The TWAMP specification gathered wide review as it [RFC4656]. The TWAMP specification gathered wide review as it
approached completion, and the by-products were several approached completion, and the by-products were several
recommendations for new features in TWAMP. There are a growing recommendations for new features in TWAMP. There are a growing
number TWAMP implementations at present, and wide-spread usage is number TWAMP implementations at present, and wide-spread usage is
skipping to change at page 7, line 20 skipping to change at page 8, line 20
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Accept | MBZ | Port | | Accept | MBZ | Port |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-| +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-|
| | | |
| SID (16 octets) | | SID (16 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Reflected octets | MBZ (2 octets) | | Reflected octets | Server octets |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| MBZ (8 octets) | | MBZ (8 octets) |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| | | |
| HMAC (16 octets) | | HMAC (16 octets) |
| | | |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The "Reflected octets" field SHALL contain the octets from the The "Reflected octets" field SHALL contain the octets from the
Request-TW-Session "Octets to be reflected" Field, and be 2 octets Request-TW-Session "Octets to be reflected" Field, and be 2 octets
long, as shown. long, as shown.
The "Server octets" field SHALL contain information that the Server
intends to be returned in the TWAMP-Test packet padding to-be-
reflected Field, OR SHALL be zero, and be 2 octets long, as shown.
Although the Server determines the SID, this field is very long (16
octets) and does not normally appear in TWAMP-Test packets.
In Truncate Padding mode, IF calculations on the Padding lengths In Truncate Padding mode, IF calculations on the Padding lengths
reveal that there are insufficient octets supplied to produce equal- reveal that there are insufficient octets supplied to produce equal-
length Session-Sender and Session-Reflector test packets, then the length Session-Sender and Session-Reflector test packets, then the
Accept Field MUST be set to 3 = some aspect of the request is not Accept Field MUST be set to 3 = some aspect of the request is not
supported. supported.
3.4. Additional considerations 3.4. Additional considerations
The value of the Modes Field sent by the Server in the Server The value of the Modes Field sent by the Server in the Server
Greeting message is the bit-wise OR of the mode values that it is Greeting message is the bit-wise OR of the mode values that it is
skipping to change at page 9, line 37 skipping to change at page 10, line 37
that the Session-Sender expects will be returned by the Session- that the Session-Sender expects will be returned by the Session-
Reflector. Reflector.
The length of the "Additional Packet Padding" Field is the difference The length of the "Additional Packet Padding" Field is the difference
between two fields in the Request-TW-Session command, as follows: between two fields in the Request-TW-Session command, as follows:
"Additional Packet Padding", in octets = "Additional Packet Padding", in octets =
"Padding Length" - "Length of padding to reflect" "Padding Length" - "Length of padding to reflect"
One possible use of the first 4 octets of the "Packet Padding (to be
reflected)" Field is shown below:
0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Client octets | Server octets |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Packet Padding (to be reflected) |
. (length in octets specified elsewhere) .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
In this example, the "Client octets" and the "Server octets" fields
contain the same information that the Client and Server exchanged in
the Request-TW-Session and Accept-Session messages corresponding to
this specific test session. These octets would be reflected the same
as the rest of the "Packet Padding (to be reflected)" Field.
4.1.3. Padding Truncation 4.1.3. Padding Truncation
When the Truncate Padding mode is selected and communicated in the When the Truncate Padding mode is selected and communicated in the
Setup Response message, the Session-Sender MUST anticipate a minimum Setup Response message, the Session-Sender MUST anticipate a minimum
padding required to achieve equal size test packets in both padding required to achieve equal size test packets in both
directions. The amount of padding needed depends on BOTH the directions. The amount of padding needed depends on BOTH the
security mode (Unauthenticated/Authenticated/Encrypted) and whether security mode (Unauthenticated/Authenticated/Encrypted) and whether
the Reflect Octets mode is selected simultaneously. the Reflect Octets mode is selected simultaneously.
When using the Truncate Padding mode, the Session-Sender MUST append When using the Truncate Padding mode, the Session-Sender MUST append
skipping to change at page 12, line 27 skipping to change at page 13, line 27
Session-Sender)" Field, and MAY re-use additional Packet Padding from Session-Sender)" Field, and MAY re-use additional Packet Padding from
the Session-Sender. The Session-Reflector MUST truncate the padding the Session-Sender. The Session-Reflector MUST truncate the padding
such that the highest number octets are discarded, and the test such that the highest number octets are discarded, and the test
packet length equals the Session-Sender's packet length. packet length equals the Session-Sender's packet length.
5. Possible Alternative 5. Possible Alternative
If new TWAMP-Test packet formats are defined, the Reflect Octets and If new TWAMP-Test packet formats are defined, the Reflect Octets and
Truncate Padding modes could be folded into one new mode. Truncate Padding modes could be folded into one new mode.
It would be possible to obtain even 4 octet boundaries in the revised
format.
It is also possible to simplfy test packet reflection by leaving the
Session-Sender's fields exactly as received, and replacing the
Discard Fill Field with the new time stamps and sequence number
determined by the Session-Reflector.
No calculations on padding are needed, and symmetrical packet size is
ensured for both directions of transmssion.
The "Packet Padding (to be reflected)" Field could contain
information that is TLV encoded, but in general the padding is opaque
to the Session-Reflector.
This Alternative is illustrated for discussion purposes. This Alternative is illustrated for discussion purposes.
New Session-Sender Test Packet Format: New Session-Sender Test Packet Format:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number | | Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp | | Timestamp |
skipping to change at page 14, line 8 skipping to change at page 15, line 8
. Additional Packet Padding . . Additional Packet Padding .
. . . .
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
The "Discard Fill" octets are discarded at the Session-Reflector. The "Discard Fill" octets are discarded at the Session-Reflector.
New Session-Reflector Test Packet format: New Session-Reflector Test Packet format:
0 1 2 3 0 1 2 3
0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sequence Number | | Sender Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Timestamp | | Sender Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Error Estimate | MBZ | | Sender Error Estimate | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Receive Timestamp | | Reflector Receive Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Sequence Number | | Reflector Sequence Number |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Timestamp | | Reflector's Sending Timestamp |
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender Error Estimate | MBZ | | Sender Error Estimate | MBZ |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Sender TTL | MBZ (3 octets) | | Sender TTL | MBZ (3 octets) |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
. . . .
. Packet Padding (from Session-Sender) . . Packet Padding (from Session-Sender) .
| | | |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
skipping to change at page 18, line 4 skipping to change at line 733
Len Ciavattone Len Ciavattone
AT&T Labs AT&T Labs
200 Laurel Avenue South 200 Laurel Avenue South
Middletown,, NJ 07748 Middletown,, NJ 07748
USA USA
Phone: +1 732 420 1239 Phone: +1 732 420 1239
Fax: Fax:
Email: lencia@att.com Email: lencia@att.com
URI: URI:
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