Re: [GROW] ixp jumbo frames doc

[john heasley]

Thu, Nov 17, 2011 at 04:23:03PM -0800, Martin J. Levy:
> Hence ... There is MSS negotiation; hence there is "value"; but I believe I 
> should only note this fact within the document and not make in any way a 
> requirement to tune or change the BGP or TCP knobs to take advantage of the 
> large MTU path.  The fact that some sessions enable this and some don't is 
> perfectly OK. It's being decided by the routers for whatever reason they 
> choose. 

enable what?  it's TCP that is concerned with the MTU (& MSS), not BGP.
a vendor might provide data about the underlying tcp connection in its
bgp session output, but that doesn't mean that BGP is concerned with its
value - its just handy debugging information for the operator.  I suppose
an implementation could use the MTU or MSS for something, but it shouldn't
need to do that if its TCP stack were implemented properly - implementation
specifc.
___
GROW mailing list
GROW@ietf.org
https://www.ietf.org/mailman/listinfo/grow

Re: [GROW] WG Adoption call for: draft-mlevy-ixp-jumboframes

[Templin, Fred L]

 

> -Original Message-
> From: grow-boun...@ietf.org [mailto:grow-boun...@ietf.org] On 
> Behalf Of Christopher Morrow
> Sent: Thursday, November 17, 2011 12:11 AM
> To: grow-cha...@tools.ietf.org; grow@ietf.org grow@ietf.org; 
> Martin J. Levy
> Subject: [GROW] WG Adoption call for: draft-mlevy-ixp-jumboframes
> 
> Given the discussion in the room today, and the current doc:
>   
> 
> can we get a poll on the adoption for this document in GROW, is this
> work that GROW should pursue?

Yes.

> Call closes 12/01/2011 (Dec 01 2011 for our non-us-participants)
> 
> -chris
> (co-chair)
> ___
> GROW mailing list
> GROW@ietf.org
> https://www.ietf.org/mailman/listinfo/grow
> 
___
GROW mailing list
GROW@ietf.org
https://www.ietf.org/mailman/listinfo/grow

Re: [GROW] ixp jumbo frames doc

[Templin, Fred L]

Hi Chris, 

> -Original Message-
> From: Christopher Morrow [mailto:christopher.mor...@gmail.com] 
> Sent: Thursday, November 17, 2011 9:48 PM
> To: Templin, Fred L
> Cc: grow-cha...@tools.ietf.org; grow@ietf.org grow@ietf.org; 
> Martin J. Levy
> Subject: Re: [GROW] ixp jumbo frames doc
> 
> On Thu, Nov 17, 2011 at 1:08 PM, Templin, Fred L
>  wrote:
> > Hi Chris,
> >
> > See below for some follow-up:
> >
> >> -Original Message-
> >> From: grow-boun...@ietf.org [mailto:grow-boun...@ietf.org] On
> >> Behalf Of Christopher Morrow
> >> Sent: Thursday, November 17, 2011 12:09 AM
> >> To: grow-cha...@tools.ietf.org; grow@ietf.org grow@ietf.org;
> >> Martin J. Levy
> >> Subject: [GROW] ixp jumbo frames doc
> >>
> >> We had a bit of a lively discussion in the meeting today about:
> >>   
> >>
> >> Some of the topics covered were:
> >>   o Is there a problem with CRC problems with 9k ?
> >
> > Please note that the concern is specifically for CRC-32.
> > Several works have discussed the error characteristics
> > of CRC-32 in relation to data set sizes:
> >
> >    Koopman, P., "32-Bit Cyclic Redundancy Codes for
> >    Internet Applications", Dec. 2002.
> >
> >    Stone, J. & Partridge, C., "When the CRC and TCP
> >    Checksum Disagree", Aug. 2000.
> >
> >    Jain, R., "Error Characteristics of Fiber Distributed
> >    Data Interface (FDDI), August 1990.
> >
> > Those works tend to support the assertion that CRC-32
> > is adequate for data set sizes up to "about 9k or even
> > a little bit more".
> >
> > That said, I can easily imagine something stronger than
> > CRC-32, and it is the responsibility of the link layer
> > to provide adequate error checking if it intends to
> > support larger MTUs.
> >
> >>   o is this something that the IEEE reigns supreme on?
> >
> > It is the link layer's job to ensure that it performs
> > adequate error checking for packets of various sizes;
> > it is not the network layer's place to guess at how well
> > the link layer is doing its job. So, the link layer's
> > advertised MTU is a certification that suitable error
> > detection will be performed for packets no larger than
> > the MTU; otherwise, it will become known as a "bad link".
> >
> >>   o should there be other methods of deployment?
> >
> > Other methods of deployment than what?
> >
> 
> Sorry, I was rushing :( One of the proposals was to use a secondary
> VLAN at the exchange for 'larger' packets, one was to forklift the
> exchange, I believe there was a third discussed in the meeting as
> well.

Thanks for the clarification; I have no further comment
on this.

> >>   o is this a BCP instead of Informational doc?
> >
> > The document is proposing jacking up the Internet cell
> > size from 1500 to 9000, where 9000 seems like a good
> > fit for the vast majority of link paths anticipated
> > for the near future. That seems like BCP to me.
> 
> Err, it's proposing setting the IXP interfaces to 'larger than 1500'.
> One of the problems is that some networks already show up at exchanges
> with 'larger than 1500 on their backbone/core facing interfaces, and
> likely on most other interfaces in the network as well, so these IXP
> interfaces are one-off situations :(

Right, but it is asking for a specific minimum MTU of
9000 in the core and is hence striving for a new
Internet cell size. IMHO, this is a necessary first
step toward migration to larger MTUs.

Don't get me wrong, though - the Internet will still
need to accommodate MTU diversity since there is no
way to legislate a sweeping change of this nature
that can be deployed all at once. That means PMTUD
will still be necessary, and should be made as robust
as possible. 
 
> I don't see this proposal as jacking up the whole of the Internet,
> there are still a vast number of edge interfaces which are not capable
> of changing MTU, but making the one-off problems go away seems like a
> good idea.

Right; there are certainly edge interfaces for which
larger MTUs are not practical. Most wireless devices
fall under that category. However, migrating the core
to 9000+ allows edge devices that can do better than
1500 to discover larger MTUs.

> > At the same time, at some point down the road we may
> > need to turn the crank again and jack up from 9000
> > to something still larger. Hence, the BCP for the
> > near term should leave open the door for an update
> > at some point in the future.
> >
> >>   o should this be adopted for WG work?
> >
> > Yes.
> 
> thanks!

Fred
fred.l.temp...@boeing.com

> -chris
> 
> > Thanks - Fred
> > fred.l.temp...@boeing.com
> >
> >> We'll pass along a separate call for adoption as well, but 
> keep these
> >> points in mind (and hopefully let's chat some about these as well)
> >>
> >> -chris
> >> (co-chair)
> >> ___
> >> GROW mailing list
> >> GROW@ietf.org
> >> https://www.ietf.org/mailman/listinfo/grow
> >>
> >
> 
__

Re: [GROW] WG Adoption Call for: draft-kirkham-private-ip-sp-cores

[Anton Ivanov]

On 17/11/11 20:37, Tony Tauber wrote:

Support.


+1



On Thu, Nov 17, 2011 at 2:30 AM, Christopher Morrow 
mailto:christopher.mor...@gmail.com>> 
wrote:


Folks,
As mentioned in the WG meeting today, please take the time to
read/review/think-about the subject draft:


Anthony et-al have done some good work documenting some practices for
operators, if the work seems to be relevant for this group, let's hear
that and we'll adopt the document. If, on the other hand, we believe
this belongs elsewhere, let's provide a pointer set to the authors.

Call for this ends: 12/01/2011 (dec 01 for you not-us-folks)

Thanks,
Chris
(co-chair)
___
GROW mailing list
GROW@ietf.org 
https://www.ietf.org/mailman/listinfo/grow



___
GROW mailing list
GROW@ietf.org
https://www.ietf.org/mailman/listinfo/grow
   



--
"If you think it's expensive to hire a professional to do the job,
wait until you hire an amateur."
Paul Neal "Red" Adair

A. R. Ivanov
E-mail:  anton.iva...@kot-begemot.co.uk

___
GROW mailing list
GROW@ietf.org
https://www.ietf.org/mailman/listinfo/grow