On Thu, Sep 26, 2024, 1:22 PM Brian E Carpenter <brian.e.carpen...@gmail.com> wrote:
> On 27-Sep-24 05:56, Templin (US), Fred L wrote: > > Hi Tom, > > > > I would like to gently suggest a new terminology. Rather than calling > them "the multi-segment buffers managed by GSO and GRO", can we begin > calling them "parcel buffers" or simply "parcels"? Not suggesting this in a > self-serving manner - I just think it is a more concise yet more > descriptive terminology. > > But that isn't the same thing. RFC2675 jumbograms are single datagrams. > They were originally intended for use over HIPPI, i.e. internally to data > centres as they existed 25 years ago, so the usage that Tom reported seems > close to what they were designed for. > > Tom, is there a full description of this usage? > Hi Brain, Here's Eric Dumazet's preso from Netdev 0x15. There's also work by Redhat and Cilium on the web. I believe this was integrated in Linux 6.3. https://netdevconf.info/0x15/session.html?BIG-TCP Tom > Regards > Brian > > > > > Thank you - Fred > > > >> -----Original Message----- > >> From: Tom Herbert <tom=40herbertland....@dmarc.ietf.org> > >> Sent: Thursday, September 26, 2024 10:15 AM > >> To: Tim Chown <tim.ch...@jisc.ac.uk> > >> Cc: Paul Vixie <p...@redbarn.org>; Templin (US), Fred L < > fred.l.temp...@boeing.com>; Internet Area <Int-area@ietf.org>; IPv6 List > >> <i...@ietf.org> > >> Subject: Re: [Int-area] Re: IP Parcels and Advanced Jumbos (AJs) > >> > >> On Thu, Sep 26, 2024 at 9:03 AM Tim Chown > >> <Tim.Chown=40jisc.ac...@dmarc.ietf.org> wrote: > >>> > >>> Hi, > >>> > >>> > >>> > >>> From: Paul Vixie <paul=40redbarn....@dmarc.ietf.org> > >>> Date: Tuesday, 24 September 2024 at 20:59 > >>> To: Templin (US), Fred L <Fred.L.Templin=40boeing....@dmarc.ietf.org>, > Internet Area <Int-area@ietf.org>, IPv6 List <i...@ietf.org> > >>> Subject: [Int-area] Re: IP Parcels and Advanced Jumbos (AJs) > >>> > >>> Something like this is long needed and will become badly needed. Every > 10X of speed increase since 10mbit/sec has gone straight to PPS, > >> whereas the speed increase from 3mbit/sec to 10mbit/sec was shared > between PPS and MTU. > >>> > >>> > >>> > >>> If every 10X has been shared between PPS and MTU, say sqrt(10) for > each, our MTU would be well over 64K by now and our PPS wouldn't > >> require dedicated NPU hardware to source, sink, and ferry those packets > at link saturation levels. > >>> > >>> > >>> > >>> Every attempt at PMTUD so far has failed but that's not an excuse to > stop trying. > >>> > >>> > >>> > >>> I think that depends on the deployment scenario and environment. In > R&E networking the adoption of 9000 MTU for large scale wide > >> area data transfers has grown, in particular by dozens of sites > worldwide that take part in the CERN experiments. CERN did a site survey > >> recently, for which I could dig out the results. > >>> > >>> > >>> > >>> The sites running 9000 MTU are interoperating with the sites still at > 1500, which is an indication that PMTUD is working well enough. The > >> large majority of CERN traffic is IPv6, so for that there’s no > fragmentation on path. > >> > >> Tim, > >> > >> That's also happening in some datacenters. I believe Google is using a > >> 9K MTU internally as it makes zero copy on hosts feasible (two 4K > >> pages per packet). Interestingly, there's also increasing use of > >> RFC2675 jumbograms, they're not sent on the wire but used internally > >> for GSO and GRO for greater than 64K packets. > >> > >> Tom > >>> > >>> > >>> > >>> The use case is somewhat constrained in that it’s only the parts of > the campus with the storage, the campus paths to the edge, and the > >> intervening R&E backbones that need to be configured. But with correct > ICMPv6 filtering, it seems robust. > >>> > >>> > >>> > >>> Best wishes, > >>> > >>> Tim > >>> > >>> > >>> > >>> > >>> > >>> Thanks for driving this Fred. > >>> > >>> > >>> > >>> p vixie > >>> > >>> > >>> > >>> On Sep 24, 2024 14:39, "Templin (US), Fred L" <Fred.L.Templin= > 40boeing....@dmarc.ietf.org> wrote: > >>> > >>> It has been a while since I have posted about this, and there are some > updates to highlight. > >>> > >>> See below for the IPv6 and IPv4 versions of “IP Parcels and Advanced > Jumbos (AJs)”: > >>> > >>> > >>> > >>> https://datatracker.ietf.org/doc/draft-templin-6man-parcels2/ > >>> > >>> https://datatracker.ietf.org/doc/draft-templin-intarea-parcels2/ > >>> > >>> > >>> > >>> The documents acknowledge that parcels are analogous to Generic > Segment/Receive Offload > >>> > >>> (GSO/GRO) but taken to the ultimate aspiration of encapsulating > multi-segment buffers in > >>> > >>> {TCP/UDP}/IP headers for transmission over parcel-capable network > paths. They further give > >>> > >>> a name to the multi-segment buffers used by GSO/GRO, suggesting that > they be called > >>> > >>> “parcel buffers” or simply “parcels”. > >>> > >>> > >>> > >>> AJs are simply single-segment parcels that can range in size from very > small to very large. > >>> > >>> They differ from ordinary jumbograms in several important ways, most > notably in terms > >>> > >>> of integrity verification and error correction. They also suggest a > new link service model > >>> > >>> that defers integrity checks to the end systems where bad data can be > discarded while > >>> > >>> good data can be accepted as an end-to-end function, reducing > retransmissions. > >>> > >>> > >>> > >>> Together, these documents cover all possible packet sizes and > configurations that may > >>> > >>> be necessary both in the near term and for the foreseeable future for > Internetworking > >>> > >>> performance maximization . Comments on the list(s) are welcome. > >>> > >>> > >>> > >>> Fred Templin > >>> > >>> _______________________________________________ > >>> Int-area mailing list -- int-area@ietf.org > >>> To unsubscribe send an email to int-area-le...@ietf.org > > > > _______________________________________________ > > Int-area mailing list -- int-area@ietf.org > > To unsubscribe send an email to int-area-le...@ietf.org >
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