TFTP Windowsize Option
RFC 7440
Document | Type |
RFC - Proposed Standard
(January 2015; No errata)
Was draft-masotta-tftpexts-windowsize-opt (individual)
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|
---|---|---|---|
Author | Patrick Masotta | ||
Last updated | 2018-12-20 | ||
Stream | IETF | ||
Formats | plain text html pdf htmlized bibtex | ||
Reviews | |||
IETF conflict review | conflict-review-masotta-tftpexts-windowsize-opt | ||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Joel Jaeggli | ||
Shepherd write-up | Show (last changed 2014-09-01) | ||
IESG | IESG state | RFC 7440 (Proposed Standard) | |
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Joel Jaeggli | ||
Send notices to | (None) | ||
IANA | IANA review state | IANA OK - No Actions Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) P. Masotta Request for Comments: 7440 Serva Category: Standards Track January 2015 ISSN: 2070-1721 TFTP Windowsize Option Abstract The "Trivial File Transfer Protocol" (RFC 1350) is a simple, lockstep, file transfer protocol that allows a client to get or put a file onto a remote host. One of its primary uses is in the early stages of nodes booting from a Local Area Network (LAN). TFTP has been used for this application because it is very simple to implement. The employment of a lockstep scheme limits throughput when used on a LAN. This document describes a TFTP option that allows the client and server to negotiate a window size of consecutive blocks to send as an alternative for replacing the single-block lockstep schema. The TFTP option mechanism employed is described in "TFTP Option Extension" (RFC 2347). 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 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7440. Masotta Standards Track [Page 1] RFC 7440 TFTP Windowsize Option January 2015 Copyright Notice Copyright (c) 2015 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 (http://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 ....................................................2 2. Conventions Used in This Document ...............................3 3. Windowsize Option Specification .................................3 4. Traffic Flow and Error Handling .................................4 5. Proof of Concept and Windowsize Evaluation ......................6 6. Congestion and Error Control ....................................7 7. Security Considerations .........................................8 8. References ......................................................9 8.1. Normative References .......................................9 Author's Address ...................................................9 1. Introduction TFTP is virtually unused for Internet transfers today, TFTP is still massively used in network boot/installation scenarios including EFI (Extensible Firmware Interface). TFTP's inherently low transfer rate has been, so far, partially mitigated by the use of the blocksize negotiated extension [RFC2348]. Using this method, the original limitation of 512-byte blocks are, in practice, replaced in Ethernet environments by blocks no larger than 1468 Bytes to avoid IP block fragmentation. This strategy produces insufficient results when transferring big files, for example, the initial ramdisk of Linux distributions or the PE images used in network installations by Microsoft WDS/MDT/SCCM. Considering TFTP looks far from extinction today, this document presents a negotiated extension, under the terms of the "TFTP Option Extension" [RFC2347], that produces TFTP transfer rates comparable to those achieved by modern file transfer protocols. Masotta Standards Track [Page 2] RFC 7440 TFTP Windowsize Option January 2015 2. Conventions Used in This Document 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 [RFC2119]. In this document, these words will appear with that interpretation only when in ALL CAPS. Lowercase uses of these words are not to be interpreted as carrying the significance given in RFC 2119. 3. Windowsize Option Specification The TFTP Read Request or Write Request packet is modified to include the windowsize option as follows. Note that all fields except "opc"Show full document text