Accommodating a Maximum Transit Unit/Maximum Receive Unit (MTU/MRU) Greater Than 1492 in the Point-to-Point Protocol over Ethernet (PPPoE)
draft-arberg-pppoe-mtu-gt1492-03
Technical Summary
Point-to-Point Protocol Over Ethernet (PPPoE), as described in RFC
2516 [1], mandates a maximum negotiated MRU of 1492. This document
outlines a solution to relax that restriction and allow a maximum
negotiated MRU greater than 1492 to minimize fragmentation in next
generation broadband networks.
Working Group Summary
"The consensus seems relatively weak to me, with a handful of
PPPoE advocates strongly voicing support for the draft, and
relative skepticism or apathy elsewhere. As it seems to be a
minor change to an Informational protocol, and in general should
enable some folks who are currently plagued with MTU problems to
have a better experience, I think it's mostly helpful."
Protocol Quality
This spec was reviewed by the pppext WG and Mark Townsley.
Note to RFC Editor
OLD:
No IANA action is required.
NEW:
This document defines a new value in a space that currently has no
IANA registry. There is work in progress to define a registry [IANA],
and that document already contains the value assigned here. No IANA
action is required for this document.
Please include an informative reference to draft-arberg-pppoe-iana-01.txt for
[IANA]
OLD:
This allows it to test that the receiving side and any intermediate
equipment can handle such packet size.
NEW:
This allows it to test that the receiving side and any intermediate
Ethernet segments and equipment can handle such packet size.
OLD:
... jumbo frames on Ethernet segments
NEW:
... frames with Ethernet packet format, but exceeding the maximum packet
lengthas defined by [REFERENCE - IEEE 802.3]
Please include the following reference for the above change:
[802.3-2005] Institute of Electrical and Electronic Engineers, IEEE
Std 802.3-2005, "IEEE Standard for Carrier Sense Multiple Access with
Collision Detection (CSMA/CD) Access Method and Physical Layer
Specifications - Draft amendment to - Information technology -
Telecommunications and information exchange between systems - Local
and metropolitan area networks - Specific requirements - Part 3:
Carrier sense multiple access with collision detection (CSMA/CD)
access method and physical layer specifications - Media Access
Control Parameters, Physical Layers and Management Parameters",
December 2005.
IESG Note
As of this writing, no current IEEE standard supports the use of
"jumbo frames" (MTU greater than 1500). Although this document
contains recommended mechanisms to detect problems in the path,
interoperability and reliability of non-standard extensions cannot
be assured. Both implementors and users of the protocol described
here should exercise caution in its use.