Network Working Group                                       T. Dreibholz
Internet-Draft                              University of Duisburg-Essen
Intended status: Experimental                              R. Seggelmann
Expires: April 28, 2012                        Muenster Univ. of Applied
                                                                Sciences
                                                                M. Becke
                                            University of Duisburg-Essen
                                                        October 26, 2011


            Sender Queue Info Option for the SCTP Socket API
             draft-dreibholz-tsvwg-sctpsocket-sqinfo-02.txt

Abstract

   This document describes an extension to the SCTP sockets API for
   querying information about the sender queue.

Status of this Memo

   This Internet-Draft is submitted in full conformance with the
   provisions of BCP 78 and BCP 79.

   Internet-Drafts are working documents of the Internet Engineering
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   time.  It is inappropriate to use Internet-Drafts as reference
   material or to cite them other than as "work in progress."

   This Internet-Draft will expire on April 28, 2012.

Copyright Notice

   Copyright (c) 2011 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
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   the Trust Legal Provisions and are provided without warranty as



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   described in the Simplified BSD License.


Table of Contents

   1.  Introduction  . . . . . . . . . . . . . . . . . . . . . . . . . 3
     1.1.  Conventions . . . . . . . . . . . . . . . . . . . . . . . . 3
   2.  Sender Queue Info (SCTP_SQINFO) . . . . . . . . . . . . . . . . 3
   3.  Security Considerations . . . . . . . . . . . . . . . . . . . . 4
   4.  IANA Considerations . . . . . . . . . . . . . . . . . . . . . . 4
   5.  Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . 4
   6.  References  . . . . . . . . . . . . . . . . . . . . . . . . . . 4
     6.1.  Normative References  . . . . . . . . . . . . . . . . . . . 4
     6.2.  Informative References  . . . . . . . . . . . . . . . . . . 5
   Authors' Addresses  . . . . . . . . . . . . . . . . . . . . . . . . 6




































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.  Introduction

   This draft describes an extension to the SCTP sockets API (see
   [I-D.ietf-tsvwg-sctpsocket],
   [I-D.dreibholz-tsvwg-sctpsocket-multipath] [RFC4960]) which allows an
   application to query the sender queue utilization per stream.  This
   information is necessary for applications to make efficient use of a
   mapping of streams to dissimilar paths.  A detailed description
   including simulation results can be found in [PFLDNeT2010].

   In particular, this API extension is useful when using the CMT-SCTP,
   CMT/RPv1-SCTP, CMT/RPv2-SCTP and MPTCP-like extensions (see
   [I-D.tuexen-tsvwg-sctp-multipath], [Globecom2010], [PAMS2011],
   [ConTEL2011], [SoftCOM2011]) for Concurrent Multipath Transfer (CMT)
   with SCTP.

1.1.  Conventions

   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 [RFC2119].


.  Sender Queue Info (SCTP_SQINFO)

   This socket option obtains the maximum sender queue size (in bytes),
   the current total sender queue utilization (in bytes) as well as the
   current utilization per stream (in bytes).

   The following structure is used to obtain the sender queue
   information:

   struct sctp_sndqueueinfo {
     sctp_assoc_t sq_assoc_id;
     uint32_t     sq_queue_limit;
     uint32_t     sq_total_queued;
     uint32_t     sq_number_of_streams;
     uint32_t     sq_queued_on_stream[];
   };

   sq_assoc_id:  This parameter is ignored for one-to-one style sockets.
      For one-to-many style sockets this parameter indicates which
      association the user is performing an action upon.  It is an error
      to use SCTP_{CURRENT|ALL}_ASSOC in sq_assoc_id.







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   sq_queue_limit:  This field gives the maximum sender queue size in
      bytes.

   sq_total_queued:  This field gives the current total sender queue
      utilization in bytes.

   sq_number_of_streams:  This field gives the number of outgoing
      streams.  That is, it will contain the number of valid
      sq_queued_on_stream entries.

   sq_queued_on_stream:  This array gives the current number of bytes
      queued for the streams 0 to sq_number_of_streams-1.

   Note, that the caller of getsockopt() MUST provide a
   sctp_sndqueueinfo structure which can hold at least as many
   sq_queued_on_stream entries as the association's number of outgoing
   streams.  Otherwise, the getsockopt() call will fail and return an
   error.


.  Security Considerations

   Security considerations for the SCTP sockets API are described by
   [I-D.ietf-tsvwg-sctpsocket].


.  IANA Considerations

   This document does not require IANA actions.


.  Acknowledgments

   The authors would like to thank Michael Tuexen and Irene Ruengeler
   for their support.


.  References

6.1.  Normative References

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

   [RFC4960]  Stewart, R., "Stream Control Transmission Protocol",
              RFC 4960, September 2007.

   [I-D.ietf-tsvwg-sctpsocket]



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              Stewart, R., Tuexen, M., Poon, K., Lei, P., and V.
              Yasevich, "Sockets API Extensions for Stream Control
              Transmission Protocol (SCTP)",
              draft-ietf-tsvwg-sctpsocket-32 (work in progress),
              October 2011.

   [I-D.dreibholz-tsvwg-sctpsocket-multipath]
              Dreibholz, T. and M. Becke, "SCTP Socket API Extensions
              for Concurrent Multipath Transfer",
              draft-dreibholz-tsvwg-sctpsocket-multipath-01 (work in
              progress), May 2011.

   [I-D.tuexen-tsvwg-sctp-multipath]
              Becke, M., Dreibholz, T., Iyengar, J., Natarajan, P., and
              M. Tuexen, "Load Sharing for the Stream Control
              Transmission Protocol (SCTP)",
              draft-tuexen-tsvwg-sctp-multipath-02 (work in progress),
              July 2011.

6.2.  Informative References

   [PFLDNeT2010]
              Dreibholz, T., Seggelmann, R., Tuexen, M., and E. Rathgeb,
              "Transmission Scheduling Optimizations for Concurrent
              Multipath Transfer", Proceedings of the 8th International
              Workshop on Protocols for Future, Large-Scale and Diverse
              Network Transports (PFLDNeT), Volume 8, ISSN 2074-5168,
              November 2010.

   [Globecom2010]
              Dreibholz, T., Becke, M., Rathgeb, E., and M. Tuexen, "On
              the Use of Concurrent Multipath Transfer over Asymmetric
              Paths", Proceedings of the IEEE Global Communications
              Conference (GLOBECOM), ISBN 978-1-4244-5637-6,
              DOI 10.1109/GLOCOM.2010.5683579, December 2010.

   [PAMS2011]
              Adhari, H., Dreibholz, T., Becke, M., Rathgeb, E., and M.
              Tuexen, "Evaluation of Concurrent Multipath Transfer over
              Dissimilar Paths", Proceedings of the 1st International
              Workshop on Protocols and Applications with Multi-Homing
              Support (PAMS), Pages 708-714, ISBN 978-0-7695-4338-3,
              DOI 10.1109/WAINA.2011.92, March 2011.

   [ConTEL2011]
              Dreibholz, T., Becke, M., Adhari, H., and E. Rathgeb, "On
              the Impact of Congestion Control for Concurrent Multipath
              Transfer on the Transport Layer", Proceedings of the 11th



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              IEEE International Conference on
              Telecommunications (ConTEL), Pages 397-404, ISBN 978-953-
              184-152-8, June 2011.

   [SoftCOM2011]
              Dreibholz, T., Becke, M., Adhari, H., and E. Rathgeb,
              "Evaluation of A New Multipath Congestion Control Scheme
              using the NetPerfMeter Tool-Chain", Proceedings of the
              19th IEEE International Conference on Software,
              Telecommunications and Computer
              Networks (SoftCOM), ISBN 978-953-290-027-9,
              September 2011.


Authors' Addresses

   Thomas Dreibholz
   University of Duisburg-Essen, Institute for Experimental Mathematics
   Ellernstrasse 29
   45326 Essen, Nordrhein-Westfalen
   Germany

   Phone: +49-201-1837637
   Fax:   +49-201-1837673
   Email: dreibh@iem.uni-due.de
   URI:   http://www.iem.uni-due.de/~dreibh/


   Robin Seggelmann
   Muenster University of Applied Sciences
   Stegerwaldstrasse 39
   48565 Steinfurt, Nordrhein-Westfalen
   Germany

   Email: seggelmann@fh-muenster.de


   Martin Becke
   University of Duisburg-Essen, Institute for Experimental Mathematics
   Ellernstrasse 29
   45326 Essen, Nordrhein-Westfalen
   Germany

   Phone: +49-201-183-7667
   Fax:   +49-201-183-7673
   Email: martin.becke@uni-due.de





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