Internet Engineering Task Force H. Stenn
Internet-Draft D. Mills
Intended status: Standards Track P. Prindeville
Expires: January 3, 2019 Network Time Foundation
July 2, 2018
Network Time Protocol: TCP Services
draft-stenn-ntp-tcp-services-00
Abstract
NTP was assigned port number 123 in 1985, in RFC 960. Traditionally,
it has only used the UDP port as while UDP is useful for time
synchronization, TCP is not suitable for time synchronization. UDP
packet have length limits, and there are rate limits imposed by the
protocol specification. Between the UDP packet length and rate
limits, some other mechanism must be provided for efficient exchange
of larger data packets. A TCP connection can be used for these uses.
Additionally, we can perform better authentication and authorization
checks using a TCP connection.
Status of This Memo
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This Internet-Draft will expire on January 3, 2019.
Copyright Notice
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Internet-Draft Network Time Protocol TCP Services July 2018
carefully, as they describe your rights and restrictions with respect
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
1.1. Requirements Language . . . . . . . . . . . . . . . . . . 2
2. NTP TCP Services . . . . . . . . . . . . . . . . . . . . . . 2
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 2
4. Security Considerations . . . . . . . . . . . . . . . . . . . 3
5. Normative References . . . . . . . . . . . . . . . . . . . . 3
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 3
1. Introduction
NTP was assigned port number 123 in 1985, in RFC 960. The NTP
protocol only uses UDP for its work, and UDP is an appropriate
protocol for time synchronization. However, there are other needs
for NTP, including monitoring and control, and ephemeral key
exchange.
For some of these cases, a TCP connection is much better.
This specification describes a high-level framework for providing TCP
services for NTP.
1.1. 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].
2. NTP TCP Services
To provide NTP TCP Services, an NTP instance establishes
communications with a TCP Listener. This could be a separate process
or it could be part of the NTP daemon. Support STARTTLS. RFC 5705
[RFC5705] RFC 7301 [RFC7301]
3. IANA Considerations
TBD
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4. Security Considerations
Additional information TBD
5. 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>.
[RFC5705] Rescorla, E., "Keying Material Exporters for Transport
Layer Security (TLS)", RFC 5705, DOI 10.17487/RFC5705,
March 2010, <https://www.rfc-editor.org/info/rfc5705>.
[RFC5905] Mills, D., Martin, J., Ed., Burbank, J., and W. Kasch,
"Network Time Protocol Version 4: Protocol and Algorithms
Specification", RFC 5905, DOI 10.17487/RFC5905, June 2010,
<https://www.rfc-editor.org/info/rfc5905>.
[RFC5906] Haberman, B., Ed. and D. Mills, "Network Time Protocol
Version 4: Autokey Specification", RFC 5906,
DOI 10.17487/RFC5906, June 2010,
<https://www.rfc-editor.org/info/rfc5906>.
[RFC7301] Friedl, S., Popov, A., Langley, A., and E. Stephan,
"Transport Layer Security (TLS) Application-Layer Protocol
Negotiation Extension", RFC 7301, DOI 10.17487/RFC7301,
July 2014, <https://www.rfc-editor.org/info/rfc7301>.
Authors' Addresses
Harlan Stenn
Network Time Foundation
P.O. Box 918
Talent, OR 97540
US
Email: stenn@nwtime.org
David L. Mills
Network Time Foundation
P.O. Box 918
Talent, OR 97540
US
Email: mills@udel.edu
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Philip Prindeville
Network Time Foundation
P.O. Box 918
Talent, OR 97540
US
Email: prindeville@ntp.org
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