Re: Signaling Message Fragmentation

Hi Sri,

I will make this even easier and reduce it to a single question:

  1) How big??

Thanks - Fred
[email protected]

> -----Original Message-----
> From: Templin, Fred L
> Sent: Tuesday, September 23, 2014 8:51 AM
> To: Templin, Fred L; Sri Gundavelli (sgundave); [email protected]
> Subject: RE: Signaling Message Fragmentation
> 
> Sri,
> 
> > I've seen some work on IPSecme WG on IKEv2 message fragmentation
> > for the same issue.
> 
> I looked at this, and the approach is roughly the same as what I have
> been talking about in SEAL [RFC5320][draft-templin-intarea-seal] for
> years. In other words, perform fragmentation and reassembly at a level
> above the encapsulating IP protocol headers and below the encapsulated
> IP protocol headers - a mid-layer fragmentation and reassembly.
> 
> So, this brings up a few questions:
> 
>   1) Does the concern apply only to large control messages, or also to
>      large data packets?
>   2) How big can the control messages get - not only for just today but
>      also going forward into the future?
>   3) Are we really so concerned about IP fragment dropping that we need
>      to bump this up to a mid-layer frag/reass?
> 
> Thanks - Fred
> [email protected]
> 
> ---
> 
> From: dmm [mailto:[email protected]] On Behalf Of Templin, Fred L
> Sent: Monday, September 22, 2014 4:45 PM
> To: Sri Gundavelli (sgundave); [email protected]
> Subject: Re: [DMM] Signaling Message Fragmentation
> 
> Hi Sri,
> 
> My understanding is that if a source sends fragmented messages it must have assurance
> that the destination has a large enough reassembly buffer. Since the minimum IPv6
> reassembly unit is only 1500 bytes, the source SHOULD NOT send fragmented packets
> larger than 1500 bytes unless there is some other means of determining whether the
> destination's reassembly buffer can accommodate the larger size.
> 
> How big do you need?
> 
> Thanks - Fred
> 
> From: dmm [mailto:[email protected]] On Behalf Of Sri Gundavelli (sgundave)
> Sent: Thursday, September 18, 2014 1:04 PM
> To: [email protected]
> Subject: [DMM] Signaling Message Fragmentation
> 
> [Discussion under the maintenance scope]
> 
> With the standardization of all the new mobility options (ANI, QoS, IFOM, MNP..etc)   and specially
> with the NAI/Domain type fields in some of those options, we are almost close to hitting the PBU/BU
> fragmentation limit.
> 
> Any thoughts on how to deal with this ? How is it solved in other message based protocols ? I've seen
> some work on IPSecme WG on IKEv2 message fragmentation for the same issue.
> 
> Should we do some thing here ? Or, if any one has invested time on this and has a proposal ? Comments
> ?
> 
> 
> 
> Regards
> Sri