Subject: [Lwip] Proposed Charter for LwIP

From: Zhen Cao <[email-masked]>
Date: Wed, 3 Nov 2010 22:38:47 +0800

Dear all,

Please find the below charter for the BOF.  Thank you for discussion.

-- 
Best regards,
Zhen

Most devices that are commonly used in the Internet of Things
applications are resource constrained.  First, they are built on top
of the constrained computing platform (e.g., with 8-bit
micro-controllers and limited RAM and ROM).  Secondly, the the
connectivity within the network and out of the network to the rest of
the Internet is constrained (e.g., some networks go down to 20kbps and
with to a maximum of few kilobits per second or intermittent
connectivity).   Thirdly, these devices are energy constrained. They
only have battery supply and the application users normally do not
change their battery for long periods of time.

IP technology is envisioned to provide a highly interoperable
environment for these smart devices.  Nevertheless, implementing the
TCP/IP protocols on the very constrained platform is not trivial.
There are lots of techniques that can be used to to make the TCP/IP
protocols lightweight to make them more suitable for constrained
devices. These include lightweight design of data structures and
packet processing, smart memory management schemes, TCP window
optimizations, and cross-layer optimizations. However, these
technologies are not well documented in one place.  This working group
will develop several documents to ensure and guide interoperable
lightweight IP protocols implementations.

Work Items:
1. Produce the "Problem Statement of Lightweight IP Protocols
Implementations" to specify the common known issues met by
implementers.  This document will be informational.

2. Produce a document describing implementation techniques that met
the challenges listed in the problem statement document. In order to
facilitate the ongoing/future developers on these constrained
platforms, there is a need to document these activities and common
technologies in implementing a lightweight IP stack.  This document
will describe techniques for producing minimized sized implementations
and implementations that minimize the use of power.

3. Develop a set of the profiles for minimal IP implementations.  The
IP protocols, either IPv4 or IPv6, include multiple mechanisms.  Some
of these mechanisms are not required for interoperability.  For
example, in IPv6 it is possible to avoid the need to fragment or
reassemble IP packets if the packet size is less than equal to 1280
bytes. Similar techniques can be found for other protocols.  These
techniques can be used to reduce the complexity of an implementation
and at the same time maintain interoperability with other
implementations.  The w.g. will document these techniques in a set of
implementation profiles.

Goals and Milestones:
  Dec 2010  - WG chartered.
  Mar 2011  - Initial draft on problem statement adopted by the WG.
  July 2011 - Initial draft on lightweight implementation techniques
              adopted by the WG.
  Mar 2012  - Initial draft on lightweight IP protocol profiles
              adopted by the WG.

---

From: JP Vasseur <[email-masked]>
Date: Fri, 5 Nov 2010 09:01:44 +0800

Dear Zhen,

Great start, comments in line

> Please find the below charter for the BOF.  Thank you for discussion.

For energy, mention that some devices (even non battery operated) can
also be energy constraint.
Add that links/nodes have different characteristics too, with flaps, ... etc

> TCP/IP protocols

IP protocol suite.

Key question... When we formed various WG, we chose to only specify 
protocol for IPv6 (6owpan, roll, core). Don't we want to do the same thing
here ?

> on the very constrained platform is not trivial.
> optimizations, and cross-layer optimizations.

Be very cautious about "cross-layer optimizations" should not translate into
cross-layer violation.

> However, these

Power efficiency is critical but also memory utilization, ... 

> implementations.  The w.g. will document these techniques in a set of

What about providing feed-back to other WGs such as 6lowpan, ROLL, CoRE, ..
on potential implication of implementation constraints on protocol designs ?

> _______________________________________________
> Lwip mailing list
> [email-masked]
> https://www.ietf.org/mailman/listinfo/lwip

---

From: Behcet Sarikaya <[email-masked]>
Date: Fri, 5 Nov 2010 06:27:18 -0700 (PDT)

Hi Zhen,
  I would like to see some statements expressing that lightweight protocol 
development for resource constrained devices is in scope.

Regards,

Behcet

----- Original Message ----
> From: Zhen Cao <[email-masked]>
> To: [email-masked]
> Cc: Bob Hinden <[email-masked]>
> Sent: Wed, November 3, 2010 9:38:47 AM
> Subject: [Lwip] Proposed Charter for LwIP
> 
> Dear all,
>

---

From: JP Vasseur <[email-masked]>
Date: Sat, 6 Nov 2010 08:25:47 +0800

> development for resource constrained devices is in scope.

Protocols will be developed in their respective WG though,

---

From: Robert Cragie <[email-masked]>
Date: Mon, 08 Nov 2010 10:08:48 +0000

Hi Zhen,

Some initial comments inline, bracketed by<RCC></RCC>

Robert

Most devices that are commonly used in the Internet of Things
applications are resource constrained.

<RCC>I would say 'many' instead of 'most'. Also I would lead this into a definition of 'resource constrained' based on the following text for the three distinct areas.</RCC>

  First, they are built on top

<RCC>They *may* only have battery supplies. Devices may also use energy harvesting, e.g. solar, which can add further constraints.</RCC>

IP technology is envisioned to provide a highly interoperable
environment for these smart devices.

<RCC>I'm not sure if highly interoperable is the right phrase. I would say IP technology provides the basis for interoperability and end-to-end connectivity for smart devices. I would also explicitly mention IPv6; I see little point in pursuing IPv4.</RCC>

  Nevertheless, implementing the

<RCC>We need to consider all three of the original resource contraints: Platform, bandwidth and energy consumption.</RCC>

Work Items:

<RCC>...and bandwidth, although the two are related.</RCC>

<RCC>IPv6 only</RCC>

Goals and Milestones:
   Dec 2010  - WG chartered.

               adopted by the WG.

Robert Cragie (Pacific Gas & Electric)

Gridmerge Ltd.
89 Greenfield Crescent,
Wakefield, WF4 4WA, UK
+44 1924 910888
+1 415 513 0064
http://www.gridmerge.com <http://www.gridmerge.com/>

---

From: ma yc <[email-masked]>
Date: Tue, 9 Nov 2010 10:55:16 +0800

Hi

Please see comment inline, bracketed by <YCMA></YCMA>

2010/11/8 Robert Cragie <[email-masked]>:
> Hi Zhen,
>
> Some initial comments inline, bracketed by <RCC></RCC>
>
> Robert
>
>
> <RCC>I'm not sure if highly interoperable is the right phrase. I would say
> IP technology provides the basis for interoperability and end-to-end
> connectivity for smart devices. I would also explicitly mention IPv6; I see
> little point in pursuing IPv4.</RCC>

<YCMA>Agree on the IPv6 indication. Also I think the work needs to
cover IP/transport/app layer rather than IP layer only. Some words are
needed to explicitly indicate that.</YCMA>

Regards
Yuanchen
> http://www.gridmerge.com