SCTP Socket API Extensions for Concurrent Multipath Transfer

Abstract

This document describes extensions to the SCTP sockets API for configuring the CMT-SCTP and CMT/RP-SCTP extensions.¶

1. Introduction

This draft describes extensions to the SCTP sockets API (see [2], [1]) which allow an application to configure the behaviour of the Concurrent Multipath Transfer (CMT) extensions CMT-SCTP, CMT/RPv1-SCTP, CMT/RPv2-SCTP and MPTCP-like (see [3], [10], [5], [4], [7], [6], [8], [9], [11]).¶

2. Concurrent Multipath Transfer and Resource Pooling Activation/Deactivation (SCTP_CMT_ON_OFF)

This socket option activates or deactivates CMT and sets the corresponding Resource Pooling variant to be applied. The sctp_assoc_value structure is used to specify the association for which the CMT state should be changed and the new CMT state.¶

Definition of the sctp_assoc_value structure:¶

struct sctp_assoc_value {
   sctp_assoc_t assoc_id;
   uint32_t     assoc_value;
};

assoc_id:

Holds the identifier for the association of which the CMT state should be changed. Ignored for one-to-one style sockets.¶

assoc_value:

0

Turns CMT off.¶

1

Turns plain CMT-SCTP on. No Resource Pooling is applied.¶

2

Turns CMT-SCTP on. CMT/RPv1 Resource Pooling as defined in [9] is applied.¶

3

Turns CMT-SCTP on. CMT/RPv2 Resource Pooling as defined in [8] is applied.¶

4

Turns CMT-SCTP on. MPTCP-like Resource Pooling as defined in [6], [8], [5] is applied.¶

3. Testbed Platform

A large-scale and realistic Internet testbed platform with support for the multi-homing feature of the underlying SCTP protocol is NorNet. A description of NorNet is provided in [12], [13], some further information can be found on the project website [14].¶

4. Security Considerations

Security considerations for the SCTP sockets API are described by [2].¶

5. IANA Considerations

This document does not require IANA actions.¶

6. Acknowledgments

The authors would like to thank Michael Tuexen for his support.¶

7. References