Internet DRAFT - draft-boucadair-mptcp-extensions
draft-boucadair-mptcp-extensions
Network Working Group M. Boucadair
Internet-Draft C. Jacquenet
Intended status: Experimental France Telecom
Expires: December 18, 2015 June 16, 2015
Negotiating the Maximum Number of MPTCP Subflows
draft-boucadair-mptcp-extensions-00
Abstract
This document specifies an experimental MPTCP option that is meant to
negotiate the maximum number of subflows that can be established and
maintained for a given MPTCP connection. The purpose is to minimize
any possible performance degradation that can be induced by a
possibly large number of establishment requests for additional
subflows if the remote endpoint is not appropriateley dimensioned to
handle such requests.
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].
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
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This Internet-Draft will expire on December 18, 2015.
Copyright Notice
Copyright (c) 2015 IETF Trust and the persons identified as the
document authors. All rights reserved.
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This document is subject to BCP 78 and the IETF Trust's Legal
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Experiment Goals . . . . . . . . . . . . . . . . . . . . 3
2. Maximum Subflows MPTCP Option . . . . . . . . . . . . . . . . 3
3. Behavior . . . . . . . . . . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
6. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 4
7. References . . . . . . . . . . . . . . . . . . . . . . . . . 4
7.1. Normative References . . . . . . . . . . . . . . . . . . 4
7.2. Informative References . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 5
1. Introduction
This document specifies a MPTCP option that is meant to indicate to a
remote peer the maximum number of subflows that can be established
within a single MPTCP connection. If the remote peer honors the
indication provided in this option, any performance degradation
induced by a possibly abusive setup of additional subflows that
exceed the said maximum becomes unlikely.
This document adheres to [I-D.bonaventure-mptcp-exp-option].
This option targets mainly MPTCP deployments within a single
administrative domain such as those MPTCP designs meant to achieve
load-balancing, for example. The use of this option contributes to
the harmonization of node configuration within an administrative
domain, so that an optimal number of subflows is maintained by
involved nodes independently of their actual performance
capabilities. This option can be used for other deployment
scenarios. It is out of scope of this document to identify an
exhaustive list of such scenarios.
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1.1. Experiment Goals
Experiments based upon the MPTCP option described in this document
are meant to help operators refine their MPTCP design and operational
procedures, by tweaking some MPTCP parameters such as the number of
subflows to be associated with a given MPTCP connection.
Experimenting with this MPTCP option should also help assess whether
this option can be used to propagate MPTCP-related optimization
parameters (derived from the number of concurrent subflows associated
to each MPTCP connection) that can be configured in a node that is
responsible for aggregating MPTCP connections established with
upstream nodes.
2. Maximum Subflows MPTCP Option
This option follows the shared experimental format defined in
[I-D.bonaventure-mptcp-exp-option] (see Figure 1).
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
+---------------+---------------+-------+-----------------------+
| Kind | Length |Subtype| Flags | Experiment |
+---------------+---------------+-------+-------+---------------+
| Id. (16 bits) | Maximum Sub-Flows |
+---------------+-----------------------------------------------+
Figure 1: Option Format
The meaning of "Kind", "Length", "Subtype", and "Flags" (especially
'S' and 'U' flags) are exactly the same as defined in
[I-D.bonaventure-mptcp-exp-option].
Experiment ID (to be assigned, see Section 5).
The "Maximum Sub-Flows" field indicates the number of maximum
concurrent subflows that can be maintained by a given MPTCP endpoint
for each MPTCP connection established by or with this endpoint. The
value of this field MUST be strictly greater than zero.
3. Behavior
The option defined in Section 2 is used by a TCP endpoint to indicate
to its corresponding peer the maximum number of subflows that it can
maintain per MPTCP connection.
If two peers (T1 and T2) indicate the maximum number of concurrent
subflows per connection they can maintain, then they MUST NOT
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maintain more than "MIN(MAX_SUBFLOW(T1), MAX_SUBFLOW(T2))" concurrent
subflows.
The absence of this option in an MPTCP control message issued by a
MPTCP endpoint is an indication that this endpoint can instantiate
any number of subflows per MPTCP connection.
If no maximum number of subflows is configured locally to an MPTCP
endpoint, it may rely on the results of procedures such as
[I-D.boucadair-mptcp-connectivity-checks] as a hint to determine the
value to include in the "Maximum Sub-Flows" MPTCP option.
4. Security Considerations
MPTCP-related security considerations are documented in [RFC6824] and
[I-D.ietf-mptcp-attacks].
5. IANA Considerations
This document requests IANA to assign an experiment ID as per
[I-D.bonaventure-mptcp-exp-option].
6. Acknowledgements
TBC
7. References
7.1. Normative References
[I-D.bonaventure-mptcp-exp-option]
Bonaventure , O., Hesmans, B., and M. Boucadair,
"Experimental Multipath TCP option", 1992.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119, March 1997.
[RFC6824] Ford, A., Raiciu, C., Handley, M., and O. Bonaventure,
"TCP Extensions for Multipath Operation with Multiple
Addresses", RFC 6824, January 2013.
7.2. Informative References
[I-D.boucadair-mptcp-connectivity-checks]
Boucadair, M. and C. Jacquenet, "MPTCP Connectivity
Checks", draft-boucadair-mptcp-connectivity-checks-00
(work in progress), March 2015.
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[I-D.ietf-mptcp-attacks]
Bagnulo, M., Paasch, C., Gont, F., Bonaventure, O., and C.
Raiciu, "Analysis of MPTCP residual threats and possible
fixes", draft-ietf-mptcp-attacks-04 (work in progress),
March 2015.
Authors' Addresses
Mohamed Boucadair
France Telecom
Rennes 35000
France
Email: mohamed.boucadair@orange.com
Christian Jacquenet
France Telecom
Rennes 35000
France
Email: christian.jacquenet@orange.com
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