diff options
Diffstat (limited to 'doc/rfc/rfc8545.txt')
-rw-r--r-- | doc/rfc/rfc8545.txt | 619 |
1 files changed, 619 insertions, 0 deletions
diff --git a/doc/rfc/rfc8545.txt b/doc/rfc/rfc8545.txt new file mode 100644 index 0000000..519ab3c --- /dev/null +++ b/doc/rfc/rfc8545.txt @@ -0,0 +1,619 @@ + + + + + + +Internet Engineering Task Force (IETF) A. Morton, Ed. +Request for Comments: 8545 AT&T Labs +Updates: 4656, 5357 G. Mirsky, Ed. +Category: Standards Track ZTE Corp. +ISSN: 2070-1721 March 2019 + + + Well-Known Port Assignments for + the One-Way Active Measurement Protocol (OWAMP) and + the Two-Way Active Measurement Protocol (TWAMP) + +Abstract + + This memo explains the motivation and describes the reassignment of + well-known ports for the One-Way Active Measurement Protocol (OWAMP) + and the Two-Way Active Measurement Protocol (TWAMP) for control and + measurement. It also clarifies the meaning and composition of these + Standards Track protocol names for the industry. + + This memo updates RFCs 4656 and 5357, in terms of the UDP well-known + port assignments, and it clarifies the complete OWAMP and TWAMP + protocol composition for the industry. + +Status of This Memo + + This is an Internet Standards Track document. + + This document is a product of the Internet Engineering Task Force + (IETF). It represents the consensus of the IETF community. It has + received public review and has been approved for publication by the + Internet Engineering Steering Group (IESG). Further information on + Internet Standards is available in Section 2 of RFC 7841. + + Information about the current status of this document, any errata, + and how to provide feedback on it may be obtained at + https://www.rfc-editor.org/info/rfc8545. + + + + + + + + + + + + + + + +Morton & Mirsky Standards Track [Page 1] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + +Copyright Notice + + Copyright (c) 2019 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 + Provisions Relating to IETF Documents + (https://trustee.ietf.org/license-info) in effect on the date of + publication of this document. Please review these documents + carefully, as they describe your rights and restrictions with respect + to this document. Code Components extracted from this document must + include Simplified BSD License text as described in Section 4.e of + the Trust Legal Provisions and are provided without warranty as + described in the Simplified BSD License. + +Table of Contents + + 1. Introduction ....................................................3 + 2. Requirements Language ...........................................3 + 3. Scope ...........................................................3 + 4. Definitions and Background ......................................3 + 5. New Well-Known Ports ............................................5 + 5.1. Impact on TWAMP-Control Protocol ...........................5 + 5.2. Impact on OWAMP-Control Protocol ...........................6 + 5.3. Impact on OWAMP-Test/TWAMP-Test Protocols ..................6 + 6. Security Considerations .........................................7 + 7. IANA Considerations .............................................8 + 8. References ......................................................8 + 8.1. Normative References .......................................8 + 8.2. Informative References .....................................9 + Appendix A. Background on TWAMP Light .............................10 + Acknowledgements ..................................................11 + Contributors ......................................................11 + Authors' Addresses ................................................11 + + + + + + + + + + + + + + + + + +Morton & Mirsky Standards Track [Page 2] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + +1. Introduction + + The IETF IP Performance Metrics (IPPM) Working Group first developed + the One-Way Active Measurement Protocol (OWAMP), as specified in + [RFC4656]. Further protocol development to support testing resulted + in the Two-Way Active Measurement Protocol (TWAMP), as specified in + [RFC5357]. + + Both OWAMP and TWAMP require the implementation of a control and mode + negotiation protocol (OWAMP-Control and TWAMP-Control) that employs + the reliable transport services of TCP (including security + configuration and key derivation). The control protocols arrange for + the configuration and management of test sessions using the + associated test protocol (OWAMP-Test or TWAMP-Test) on UDP transport. + + The IETF recognizes the value of assigning a well-known UDP port to + the OWAMP-Test and TWAMP-Test protocols and also recognizes that this + goal can be easily arranged through port reassignments. + +2. Requirements Language + + The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", + "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and + "OPTIONAL" in this document are to be interpreted as described in + BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all + capitals, as shown here. + +3. Scope + + The scope of this memo is twofold: (1) to reallocate the well-known + ports for the UDP test protocols that compose necessary parts of + their respective Standards Track protocols (OWAMP and TWAMP) and + (2) to clarify the meaning and composition of these Standards Track + protocol names for the industry. + + This memo updates [RFC4656] and [RFC5357], in terms of the UDP + well-known port assignments. + +4. Definitions and Background + + This section defines key terms and clarifies the required composition + of the OWAMP and TWAMP Standards Track protocols. + + "OWAMP-Control" is the protocol defined in Section 3 of [RFC4656]. + + "OWAMP-Test" is the protocol defined in Section 4 of [RFC4656]. + + + + + +Morton & Mirsky Standards Track [Page 3] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + + OWAMP is described in this direct quote from Section 1.1 of + [RFC4656]: "OWAMP actually consists of two inter-related protocols: + OWAMP-Control and OWAMP-Test." A similar sentence appears in + Section 2 of [RFC4656]. For avoidance of doubt, the implementation + of both OWAMP-Control and OWAMP-Test is REQUIRED for Standards Track + OWAMP as specified in [RFC4656] (applying the consensus of many + dictionary definitions of "consist"). + + "TWAMP-Control" is the protocol defined in Section 3 of [RFC5357]. + + "TWAMP-Test" is the protocol defined in Section 4 of [RFC5357]. + + TWAMP is described in this direct quote from Section 1.1 of + [RFC5357]: "Similar to OWAMP [RFC4656], TWAMP consists of two + inter-related protocols: TWAMP-Control and TWAMP-Test." For + avoidance of doubt, the implementation of both TWAMP-Control and + TWAMP-Test is REQUIRED for Standards Track TWAMP as specified in + [RFC5357] (applying the consensus of many dictionary definitions of + "consist"). + + "TWAMP Light" is an idea described in Appendix I ("TWAMP Light + (Informative)") of [RFC5357]; TWAMP Light includes an unspecified + control protocol combined with the TWAMP-Test protocol. In + [RFC5357], the TWAMP Light idea was relegated to Appendix I because + TWAMP Light failed to meet the requirements for IETF protocols (there + are no specifications for negotiating this form of operation and no + specifications for mandatory-to-implement security features), as + described in Appendix A of this memo. See also [LarsAD] and + [TimDISCUSS]. + + Since the idea of TWAMP Light clearly includes the TWAMP-Test + component of TWAMP, it is considered reasonable for future systems to + use the TWAMP-Test well-known UDP port (whose reallocated assignment + is specified in this document). Clearly, the TWAMP Light idea + envisions many components and communication capabilities beyond + TWAMP-Test (implementing the security requirements, for example); + otherwise, Appendix I of [RFC5357] would be one sentence long + (equating TWAMP Light with TWAMP-Test only). + + + + + + + + + + + + + +Morton & Mirsky Standards Track [Page 4] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + +5. New Well-Known Ports + + Originally, both TCP and UDP well-known ports were assigned to the + control protocols that are essential components of Standards Track + OWAMP and TWAMP. + + Since OWAMP-Control and TWAMP-Control require TCP transport, they + cannot make use of the UDP ports that were originally assigned. + However, test sessions using OWAMP-Test or TWAMP-Test operate on UDP + transport. + + Per this memo, IANA has reassigned the UDP well-known port from the + control protocol to the test protocol (see Section 7 ("IANA + Considerations")). The use of this UDP port is OPTIONAL in Standards + Track OWAMP and TWAMP. It may simplify some operations to have a + well-known port available for the test protocols or for future + specifications involving TWAMP-Test to use this port as a default + port. For example, [TR-390] is a specification for testing at the + customer edge of IP networks, and conforming implementations will + benefit from reallocation of the well-known UDP port to the test + protocol. + +5.1. Impact on TWAMP-Control Protocol + + Section 3.5 of [RFC5357] describes the detailed process of + negotiating the Receiver Port number, on which the TWAMP + Session-Reflector will send and receive TWAMP-Test packets; see the + quoted text below. The Control-Client, acting on behalf of the + Session-Sender, proposes the Receiver Port number from the Dynamic + Ports range [RFC6335]: + + The Receiver Port is the desired UDP port to which TWAMP-Test + packets will be sent by the Session-Sender (the port where the + Session-Reflector is asked to receive test packets). The Receiver + Port is also the UDP port from which TWAMP-Test packets will be + sent by the Session-Reflector (the Session-Reflector will use the + same UDP port to send and receive packets). + + It is possible that the proposed Receiver Port may not be available, + e.g., the port is in use by another test session or another + application. In this case, we update the last paragraph of + Section 3.5 of [RFC5357] per Erratum ID 1587 (see + <https://www.rfc-editor.org/errata/eid1587>) as follows: + + ... the Server at the Session-Reflector MAY suggest an alternate + and available port for this session in the Port field. The + Control-Client either accepts the alternate port or composes a new + Session-Request message with suitable parameters. Otherwise, the + + + +Morton & Mirsky Standards Track [Page 5] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + + Server uses the Accept field to convey other forms of session + rejection or failure to the Control-Client and MUST NOT suggest an + alternate port; in this case, the Port field MUST be set to zero. + + A Control-Client that supports the use of the allocated TWAMP-Test + Receiver Port (Section 7) MAY request to use that port number in the + Request-TW-Session command. If the Server does not support the + allocated TWAMP-Test Receiver Port, then it sends an alternate port + number in the Accept-Session message with Accept field = 0. Thus, + the deployment of the allocated TWAMP Receiver Port number is + backward compatible with existing TWAMP-Control solutions that are + based on [RFC5357]. Of course, using a UDP port number chosen from + the Dynamic Ports range [RFC6335] will help avoid the situation where + the Control-Client or Server finds that the proposed port is already + in use. + +5.2. Impact on OWAMP-Control Protocol + + As described above, an OWAMP-Control client that supports the use of + the allocated OWAMP-Test Receiver Port (Section 7) MAY request to use + that port number in the Request-Session command. If the Server does + not support the allocated OWAMP-Test Receiver Port (or does not have + the port available), then it sends an alternate port number in the + Accept-Session message with Accept field = 0. Further exchanges + proceed as already specified. + +5.3. Impact on OWAMP-Test/TWAMP-Test Protocols + + OWAMP-Test/TWAMP-Test may be used to measure IP performance metrics + in an Equal-Cost Multipath (ECMP) environment. Though algorithms to + balance IP flows among available paths have not been standardized, + the most common is the five-tuple that uses destination IP address, + source IP address, protocol type, destination port number, and source + port number. When attempting to monitor different paths in an ECMP + network, it is sufficient to vary only one of five parameters, e.g., + the source port number. Thus, there will be no negative impact on + the ability to arrange concurrent OWAMP/TWAMP test sessions between + the same test points to monitor different paths in the ECMP network + when using the reallocated UDP port number as the Receiver Port, as + using the port is optional. + + + + + + + + + + + +Morton & Mirsky Standards Track [Page 6] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + +6. Security Considerations + + The security considerations that apply to any active measurement of + live paths are relevant here as well (see [RFC4656] and [RFC5357]). + + When considering the privacy of those involved in measurement or + those whose traffic is measured, the sensitive information available + to potential observers is greatly reduced when using active + techniques that are within this scope of work. Passive observations + of user traffic for measurement purposes raise many privacy issues. + We refer the reader to the security and privacy considerations + described in the Large-Scale Measurement of Broadband Performance + (LMAP) framework [RFC7594], which covers both active and passive + techniques. + + The registered UDP port as the Receiver Port for OWAMP-Test/ + TWAMP-Test could become a target of denial of service (DoS) or could + be used to aid man-in-the-middle (MITM) attacks. To improve + protection against DoS, the following methods are recommended: + + o filtering access to the OWAMP/TWAMP Receiver Port via an + access list. + + o using a non-globally routable IP address for the OWAMP/TWAMP + Session-Reflector address. + + A MITM attacker may try to modify the contents of the OWAMP-Test/ + TWAMP-Test packets in order to alter the measurement results. + However, an implementation can use authenticated mode to detect + modification of data. In addition, an implementation can use + encrypted mode to prevent eavesdropping and undetected modification + of the OWAMP-Test/TWAMP-Test packets. + + There is also the risk of a network under test giving special + treatment to flows involving the well-known UDP port, with or without + knowing source and destination addresses of measurement systems, and + thus biasing the results through preferential or detrimental + processing. + + + + + + + + + + + + + +Morton & Mirsky Standards Track [Page 7] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + +7. IANA Considerations + + IANA has reallocated two UDP port numbers from the System Ports range + of the "Service Name and Transport Protocol Port Number Registry" + [RFC6335]. Specifically, IANA has reallocated UDP ports 861 and 862 + as shown below, leaving the TCP port assignments as is. IANA has + also updated the Assignee and Contact for these ports (both UDP and + TCP) to be the IESG and the IETF Chair, respectively. + + +---------------+--------+-----------+------------------+-----------+ + | Service | Port | Transport | Description | Reference | + | Name | Number | Protocol | | | + +---------------+--------+-----------+------------------+-----------+ + | owamp-control | 861 | tcp | OWAMP-Control | RFC 4656 | + | owamp-test | 861 | udp | OWAMP-Test | RFC 8545 | + | | | | Receiver Port | | + | | | | | | + | twamp-control | 862 | tcp | TWAMP-Control | RFC 5357 | + | twamp-test | 862 | udp | TWAMP-Test | RFC 8545 | + | | | | Receiver Port | | + +---------------+--------+-----------+------------------+-----------+ + +8. References + +8.1. Normative References + + [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>. + + [RFC4656] Shalunov, S., Teitelbaum, B., Karp, A., Boote, J., and + M. Zekauskas, "A One-way Active Measurement Protocol + (OWAMP)", RFC 4656, DOI 10.17487/RFC4656, September 2006, + <https://www.rfc-editor.org/info/rfc4656>. + + [RFC5357] Hedayat, K., Krzanowski, R., Morton, A., Yum, K., and + J. Babiarz, "A Two-Way Active Measurement Protocol + (TWAMP)", RFC 5357, DOI 10.17487/RFC5357, October 2008, + <https://www.rfc-editor.org/info/rfc5357>. + + [RFC6335] Cotton, M., Eggert, L., Touch, J., Westerlund, M., and + S. Cheshire, "Internet Assigned Numbers Authority (IANA) + Procedures for the Management of the Service Name and + Transport Protocol Port Number Registry", BCP 165, + RFC 6335, DOI 10.17487/RFC6335, August 2011, + <https://www.rfc-editor.org/info/rfc6335>. + + + + +Morton & Mirsky Standards Track [Page 8] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + + [RFC7594] Eardley, P., Morton, A., Bagnulo, M., Burbridge, T., + Aitken, P., and A. Akhter, "A Framework for Large-Scale + Measurement of Broadband Performance (LMAP)", RFC 7594, + DOI 10.17487/RFC7594, September 2015, + <https://www.rfc-editor.org/info/rfc7594>. + + [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in + RFC 2119 Key Words", BCP 14, RFC 8174, + DOI 10.17487/RFC8174, May 2017, + <https://www.rfc-editor.org/info/rfc8174>. + +8.2. Informative References + + [IPPM-TWAMP-06] + Hedayat, K., Krzanowski, R., Yum, K., Morton, A., and + J. Babiarz, "A Two-way Active Measurement Protocol + (TWAMP)", Work in Progress, draft-ietf-ippm-twamp-06, + December 2007. + + [LarsAD] Eggert, L., "Subject: [ippm] AD review: + draft-ietf-ippm-twamp-06.txt", message to the ippm mailing + list, April 2008, <https://mailarchive.ietf.org/ + rch/msg/ippm/LzcTPYhPhWhbb5-ncR046XKpnzo>. + + [TimDISCUSS] + "Tim Polk's Ballot discuss", July 2008, + <https://datatracker.ietf.org/doc/rfc5357/history>. + + [TR-390] Broadband Forum, "TR-390: Performance Measurement from IP + Edge to Customer Equipment using TWAMP Light", Issue: 1, + May 2017, <https://www.broadband-forum.org/technical/ + download/TR-390.pdf>. + + + + + + + + + + + + + + + + + + + +Morton & Mirsky Standards Track [Page 9] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + +Appendix A. Background on TWAMP Light + + This informative appendix provides the background on the decision to + move the TWAMP Light idea to an informative appendix in [RFC5357]. + + As also noted in Section 4, the TWAMP Light idea was relegated to + Appendix I of [RFC5357] because it failed to meet the requirements + for IETF protocols (there are no specifications for negotiating this + form of operation and no specifications for mandatory-to-implement + security features), as described in the references cited below: + + o Lars Eggert's Area Director review [LarsAD], where he pointed out + that having two variants of TWAMP (TWAMP Light and Complete TWAMP) + requires a protocol mechanism to negotiate which variant will be + used. Note that "Complete TWAMP" is called "Standards Track + TWAMP" in this document. See Lars's "Section 5.2, paragraph 0" + comment on [LarsAD], which refers to a section in [IPPM-TWAMP-06]. + The working group consensus was to place the TWAMP Light + description in Appendix I and to refer to that appendix only as an + "incremental path to adopting TWAMP, by implementing the + TWAMP-Test protocol first." + + o Tim Polk's "Ballot discuss" of 2008-07-16 [TimDISCUSS], which + points out that TWAMP Light was an incomplete specification + because the key required for authenticated and encrypted modes + depended on the TWAMP-Control Session key. Additional requirement + statements were added in Appendix I to address Tim's Ballot + discuss (see the last three paragraphs of Appendix I in + [RFC5357]). + + Since the idea of TWAMP Light clearly includes the TWAMP-Test + protocol and other undefined facilities, Appendix I of [RFC5357] + simply describes ideas for how TWAMP-Test might be used outside of + the context of Standards Track TWAMP. + + + + + + + + + + + + + + + + + +Morton & Mirsky Standards Track [Page 10] + +RFC 8545 OWAMP/TWAMP Well-Known Ports March 2019 + + +Acknowledgements + + The authors thank the IPPM Working Group for their rapid review; + thanks also to Muthu Arul Mozhi Perumal and Luay Jalil for their + participation and suggestions. + +Contributors + + Richard Foote and Luis M. Contreras made notable contributions on + this topic. + +Authors' Addresses + + Al Morton (editor) + AT&T Labs + 200 Laurel Avenue South + Middletown, NJ 07748 + United States of America + + Phone: +1 732 420 1571 + Fax: +1 732 368 1192 + Email: acmorton@att.com + + + Greg Mirsky (editor) + ZTE Corp. + + Email: gregimirsky@gmail.com + + + + + + + + + + + + + + + + + + + + + + + +Morton & Mirsky Standards Track [Page 11] + |