RFC 8303
On the Usage of Transport Features Provided by IETF Transport Protocols
6. IANA Considerations
This document does not require any IANA actions.7. Security Considerations
Authentication, confidentiality protection, and integrity protection are identified as transport features [RFC8095]. These transport features are generally provided by a protocol or layer on top of the transport protocol; none of the transport protocols considered in this document provides these transport features on its own. Therefore, these transport features are not considered in this document, with the exception of native authentication capabilities of TCP and SCTP for which the security considerations in [RFC5925] and [RFC4895] apply. Security considerations for the use of UDP and UDP-Lite are provided in the referenced RFCs. Security guidance for application usage is provided in the UDP Guidelines [RFC8085].
8. References
8.1. Normative References
[RFC0793] Postel, J., "Transmission Control Protocol", STD 7, RFC 793, DOI 10.17487/RFC0793, September 1981, <https://www.rfc-editor.org/info/rfc793>. [RFC1122] Braden, R., Ed., "Requirements for Internet Hosts - Communication Layers", STD 3, RFC 1122, DOI 10.17487/RFC1122, October 1989, <https://www.rfc-editor.org/info/rfc1122>. [RFC3758] Stewart, R., Ramalho, M., Xie, Q., Tuexen, M., and P. Conrad, "Stream Control Transmission Protocol (SCTP) Partial Reliability Extension", RFC 3758, DOI 10.17487/RFC3758, May 2004, <https://www.rfc-editor.org/info/rfc3758>. [RFC4895] Tuexen, M., Stewart, R., Lei, P., and E. Rescorla, "Authenticated Chunks for the Stream Control Transmission Protocol (SCTP)", RFC 4895, DOI 10.17487/RFC4895, August 2007, <https://www.rfc-editor.org/info/rfc4895>. [RFC4960] Stewart, R., Ed., "Stream Control Transmission Protocol", RFC 4960, DOI 10.17487/RFC4960, September 2007, <https://www.rfc-editor.org/info/rfc4960>. [RFC5061] Stewart, R., Xie, Q., Tuexen, M., Maruyama, S., and M. Kozuka, "Stream Control Transmission Protocol (SCTP) Dynamic Address Reconfiguration", RFC 5061, DOI 10.17487/RFC5061, September 2007, <https://www.rfc-editor.org/info/rfc5061>. [RFC5482] Eggert, L. and F. Gont, "TCP User Timeout Option", RFC 5482, DOI 10.17487/RFC5482, March 2009, <https://www.rfc-editor.org/info/rfc5482>. [RFC5925] Touch, J., Mankin, A., and R. Bonica, "The TCP Authentication Option", RFC 5925, DOI 10.17487/RFC5925, June 2010, <https://www.rfc-editor.org/info/rfc5925>. [RFC6182] Ford, A., Raiciu, C., Handley, M., Barre, S., and J. Iyengar, "Architectural Guidelines for Multipath TCP Development", RFC 6182, DOI 10.17487/RFC6182, March 2011, <https://www.rfc-editor.org/info/rfc6182>.
[RFC6458] Stewart, R., Tuexen, M., Poon, K., Lei, P., and V. Yasevich, "Sockets API Extensions for the Stream Control Transmission Protocol (SCTP)", RFC 6458, DOI 10.17487/RFC6458, December 2011, <https://www.rfc-editor.org/info/rfc6458>. [RFC6525] Stewart, R., Tuexen, M., and P. Lei, "Stream Control Transmission Protocol (SCTP) Stream Reconfiguration", RFC 6525, DOI 10.17487/RFC6525, February 2012, <https://www.rfc-editor.org/info/rfc6525>. [RFC6817] Shalunov, S., Hazel, G., Iyengar, J., and M. Kuehlewind, "Low Extra Delay Background Transport (LEDBAT)", RFC 6817, DOI 10.17487/RFC6817, December 2012, <https://www.rfc-editor.org/info/rfc6817>. [RFC6824] Ford, A., Raiciu, C., Handley, M., and O. Bonaventure, "TCP Extensions for Multipath Operation with Multiple Addresses", RFC 6824, DOI 10.17487/RFC6824, January 2013, <https://www.rfc-editor.org/info/rfc6824>. [RFC6897] Scharf, M. and A. Ford, "Multipath TCP (MPTCP) Application Interface Considerations", RFC 6897, DOI 10.17487/RFC6897, March 2013, <https://www.rfc-editor.org/info/rfc6897>. [RFC6951] Tuexen, M. and R. Stewart, "UDP Encapsulation of Stream Control Transmission Protocol (SCTP) Packets for End-Host to End-Host Communication", RFC 6951, DOI 10.17487/RFC6951, May 2013, <https://www.rfc-editor.org/info/rfc6951>. [RFC7053] Tuexen, M., Ruengeler, I., and R. Stewart, "SACK- IMMEDIATELY Extension for the Stream Control Transmission Protocol", RFC 7053, DOI 10.17487/RFC7053, November 2013, <https://www.rfc-editor.org/info/rfc7053>. [RFC7413] Cheng, Y., Chu, J., Radhakrishnan, S., and A. Jain, "TCP Fast Open", RFC 7413, DOI 10.17487/RFC7413, December 2014, <https://www.rfc-editor.org/info/rfc7413>. [RFC7496] Tuexen, M., Seggelmann, R., Stewart, R., and S. Loreto, "Additional Policies for the Partially Reliable Stream Control Transmission Protocol Extension", RFC 7496, DOI 10.17487/RFC7496, April 2015, <https://www.rfc-editor.org/info/rfc7496>.
[RFC7829] Nishida, Y., Natarajan, P., Caro, A., Amer, P., and K. Nielsen, "SCTP-PF: A Quick Failover Algorithm for the Stream Control Transmission Protocol", RFC 7829, DOI 10.17487/RFC7829, April 2016, <https://www.rfc-editor.org/info/rfc7829>. [RFC8085] Eggert, L., Fairhurst, G., and G. Shepherd, "UDP Usage Guidelines", BCP 145, RFC 8085, DOI 10.17487/RFC8085, March 2017, <https://www.rfc-editor.org/info/rfc8085>. [RFC8260] Stewart, R., Tuexen, M., Loreto, S., and R. Seggelmann, "Stream Schedulers and User Message Interleaving for the Stream Control Transmission Protocol", RFC 8260, DOI 10.17487/RFC8260, November 2017, <https://www.rfc-editor.org/info/rfc8260>. [RFC8304] Fairhurst, G. and T. Jones, "Transport Features of the User Datagram Protocol (UDP) and Lightweight UDP (UDP- Lite)", RFC 8304, DOI 10.17487/RFC8304, February 2018, <https://www.rfc-editor.org/info/rfc8304>.8.2. Informative References
[RFC0854] Postel, J. and J. Reynolds, "Telnet Protocol Specification", STD 8, RFC 854, DOI 10.17487/RFC0854, May 1983, <https://www.rfc-editor.org/info/rfc854>. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/info/rfc2119>. [RFC2474] Nichols, K., Blake, S., Baker, F., and D. Black, "Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers", RFC 2474, DOI 10.17487/RFC2474, December 1998, <https://www.rfc-editor.org/info/rfc2474>. [RFC2475] Blake, S., Black, D., Carlson, M., Davies, E., Wang, Z., and W. Weiss, "An Architecture for Differentiated Services", RFC 2475, DOI 10.17487/RFC2475, December 1998, <https://www.rfc-editor.org/info/rfc2475>. [RFC3260] Grossman, D., "New Terminology and Clarifications for Diffserv", RFC 3260, DOI 10.17487/RFC3260, April 2002, <https://www.rfc-editor.org/info/rfc3260>.
[RFC5461] Gont, F., "TCP's Reaction to Soft Errors", RFC 5461, DOI 10.17487/RFC5461, February 2009, <https://www.rfc-editor.org/info/rfc5461>. [RFC6093] Gont, F. and A. Yourtchenko, "On the Implementation of the TCP Urgent Mechanism", RFC 6093, DOI 10.17487/RFC6093, January 2011, <https://www.rfc-editor.org/info/rfc6093>. [RFC7414] Duke, M., Braden, R., Eddy, W., Blanton, E., and A. Zimmermann, "A Roadmap for Transmission Control Protocol (TCP) Specification Documents", RFC 7414, DOI 10.17487/RFC7414, February 2015, <https://www.rfc-editor.org/info/rfc7414>. [RFC7657] Black, D., Ed. and P. Jones, "Differentiated Services (Diffserv) and Real-Time Communication", RFC 7657, DOI 10.17487/RFC7657, November 2015, <https://www.rfc-editor.org/info/rfc7657>. [RFC8095] Fairhurst, G., Ed., Trammell, B., Ed., and M. Kuehlewind, Ed., "Services Provided by IETF Transport Protocols and Congestion Control Mechanisms", RFC 8095, DOI 10.17487/RFC8095, March 2017, <https://www.rfc-editor.org/info/rfc8095>. [TAPS-MINSET] Welzl, M. and S. Gjessing, "A Minimal Set of Transport Services for TAPS Systems", Work in Progress, draft-ietf- taps-minset-01, February 2018.
Appendix A. Overview of RFCs Used as Input for Pass 1
TCP: [RFC0793], [RFC1122], [RFC5482], [RFC5925], and [RFC7413]. MPTCP: [RFC6182], [RFC6824], and [RFC6897]. SCTP: RFCs without a sockets API specification: [RFC3758], [RFC4895], [RFC4960], and [RFC5061]. RFCs that include a sockets API specification: [RFC6458], [RFC6525], [RFC6951], [RFC7053], [RFC7496], and [RFC7829]. UDP(-Lite): See [RFC8304]. LEDBAT: [RFC6817].Appendix B. How This Document Was Developed
This section gives an overview of the method that was used to develop this document. It was given to contributors for guidance, and it can be helpful for future updates or extensions. This document is only concerned with transport features that are explicitly exposed to applications via primitives. It also strictly follows RFC text: if a transport feature is truly relevant for an application, the RFCs should say so, and they should describe how to use and configure it. Thus, the approach followed for developing this document was to identify the right RFCs, then analyze and process their text. Primitives that "MAY" be implemented by a transport protocol were excluded. To be included, the minimum requirement level for a primitive to be implemented by a protocol was "SHOULD". Where style requirement levels as described in [RFC2119] are not used, primitives were excluded when they are described in conjunction with statements like, e.g., "some implementations also provide" or "an implementation may also". Excluded primitives or parameters were briefly described in a dedicated subsection. Pass 1: This began by identifying text that talks about primitives. An API specification, abstract or not, obviously describes primitives -- but we are not *only* interested in API specifications. The text describing the 'Send' primitive in the API specified in [RFC0793],
for instance, does not say that data transfer is reliable. TCP's reliability is clear, however, from this text in Section 1 of [RFC0793]: The Transmission Control Protocol (TCP) is intended for use as a highly reliable host-to-host protocol between hosts in packet- switched computer communication networks, and in interconnected systems of such networks. Some text for the pass 1 subsections was developed by copying and pasting all the relevant text parts from the relevant RFCs then adjusting the terminology to match that in Section 2 and shortening phrasing to match the general style of the document. An effort was made to formulate everything as a primitive description such that the primitive descriptions became as complete as possible (e.g., the 'SEND.TCP' primitive in pass 2 is explicitly described as reliably transferring data); text that is relevant for the primitives presented in this pass but still does not fit directly under any primitive was used in a subsection's introduction. Pass 2: The main goal of this pass is unification of primitives. As input, only text from pass 1 was used (no exterior sources). The list in pass 2 is not arranged by protocol (i.e., "first protocol X, here are all the primitives; then protocol Y, here are all the primitives, ...") but by primitive (i.e., "primitive A, implemented this way in protocol X, this way in protocol Y, ..."). It was a goal to obtain as many similar pass 2 primitives as possible. For instance, this was sometimes achieved by not always maintaining a 1:1 mapping between pass 1 and pass 2 primitives, renaming primitives, etc. For every new primitive, the already-existing primitives were considered to try to make them as coherent as possible. For each primitive, the following style was used: o PRIMITIVENAME.PROTOCOL: Pass 1 primitive/event: Parameters: Returns: Comments: The entries "Parameters", "Returns", and "Comments" were skipped when a primitive had no parameters, no described return value, or no comments seemed necessary, respectively. Optional parameters are followed by "(optional)". When known, default values were provided. Pass 3: The main point of this pass is to identify transport features that are the result of static properties of protocols, for which all protocols have to be listed together; this is then the final list of
all available transport features. This list was primarily based on text from pass 2, with additional input from pass 1 (but no external sources).Acknowledgements
The authors would like to thank (in alphabetical order) Bob Briscoe, Spencer Dawkins, Aaron Falk, David Hayes, Karen Nielsen, Tommy Pauly, Joe Touch, and Brian Trammell for providing valuable feedback on this document. We especially thank Christoph Paasch for providing input related to Multipath TCP and Gorry Fairhurst and Tom Jones for providing input related to UDP(-Lite). This work has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No. 644334 (NEAT).Authors' Addresses
Michael Welzl University of Oslo PO Box 1080 Blindern Oslo N-0316 Norway Email: michawe@ifi.uio.no Michael Tuexen Muenster University of Applied Sciences Stegerwaldstrasse 39 Steinfurt 48565 Germany Email: tuexen@fh-muenster.de Naeem Khademi University of Oslo PO Box 1080 Blindern Oslo N-0316 Norway Email: naeemk@ifi.uio.no