Subject: [Lwip] Comments on draft-ma-lwip-stack-analysis-00

From: Hui Deng <[email-masked]>
Date: Thu, 28 Oct 2010 20:16:35 +0800

Hello all

I  suppport this bof, especially it benefits for most M2M implementers who
is
not familiar with IP based solution as we experience today.

Thanks for writing this draft which does list several similar questions we
experienced as well.
comments below:

title of this draft seems more like implementation guide other than stack
analysis.

section 2.3, does packet need a gateway? how could it be sent outside
directly?
if you have any several message, how it could consume lots of energy?

Section 3.1.3, this is a good analysis, this may lead to propose future
client-client communication

3.1.1 if multicast is not support, how could neighbor discovery be used
there?

3.1.2 do you have any idea about where you plan to use TCP?

3.2.1, does freescale always use event drive schedule?

Do you have any data analysis on those implementation.

Best regards,

-Hui

---

From: Xuan He <[email-masked]>
Date: Fri, 29 Oct 2010 11:46:52 +0800

Hi

Thank you for your comments, here are details for the Atmel solution in
section 2.3:

[ In the Atmel 6LoWPAN solution, the board which connects the
802.15.4 low-power wireless network to the real IPv6 network, be it
either Ethernet or WiFi, is called the
"edge router". The edge router in this solution is the PAN coordinator
 (such as AT91SAM7X-EK, due to the Ethernet interface available on the board
), or SAM7X board.

In addition, t
o communicate with other IPv6 nodes outside the local network, a
native IPv6 connection, or IPv6 tunnel end point, is required.
]

At present, we did not analyze the energy consumption of a variety of
solutions.

About section 3.2.1, as far as I know, schedules of Freescale platform for
WSN are event driven, and I already asked Freescale technical support, I
will feedback their views timely.

Regards,
Hex

2010/10/28 Hui Deng <[email-masked]>

Hello all

---

From: Hui Deng <[email-masked]>
Date: Fri, 29 Oct 2010 22:49:12 +0800

inline please,

2010/10/29 Xuan He <[email-masked]>

> 802.15.4 low-power wireless network to the real IPv6 network, be it either Ethernet or WiFi, is called the
>  (such as AT91SAM7X-EK, due to
> the Ethernet interface available on the board), or SAM7X board.
>
>
> In addition, t
> o communicate with other IPv6 nodes outside the local network, a native IPv6 connection, or IPv6 tunnel end point, is required.
> ]
>
Just curious about whether this special sensor Ipv6 node could directly
communicate with public IPv6 node
without going through any gateway, thanks.

> At present, we did not analyze the energy consumption of a variety of
ok, thanks,

> will feedback their views timely.

thanks a lot

-Hui

---

From: ma yc <[email-masked]>
Date: Sun, 31 Oct 2010 19:53:26 +0800

Hui

Thank you very much for the comments, please check inline.

> title of this draft seems more like implementation guide other than stack
Indeed the intention is to provide implementation guide for
lightweight IP stack.
However in the first step we just analyzed the stack. The title may change
according to the discussion and comments from the ML.

> 3.1.1 if multicast is not support, how could neighbor discovery be used
In our implementation 802.15.4 provide MAC broadcast address and ND
can utilize that address. Is there environment where multicast is not
supported in the MAC layer?

> 3.1.2 do you have any idea about where you plan to use TCP?
In our implementation there is no specific requirement for TCP.
As for work in IETF, CoAP only mandates UDP now.
For other applications, as mentioned in draft-cao-lwip-tcp-hc
the requirement from ZigBee alliance may be one candidate.

---

From: Zhen Cao <[email-masked]>
Date: Sun, 31 Oct 2010 23:30:24 +0800

On Fri, Oct 29, 2010 at 10:49 PM, Hui Deng <[email-masked]> wrote:
>> "edge
>> router". The edge router in this solution is the PAN coordinator (such as AT91SAM7X-EK, due to the Ethernet interface available on the board), or SAM7X board.
>>
>>
>> In addition, to communicate with other IPv6 nodes outside the local network, a native IPv6 connection, or IPv6 tunnel end point, is required.
>> ]
>

They are compressed IP, so It is direct.  Even if you are using the
local IP network with RFC1918 address, there will be gateway and it is
hard to say the communications are not direct.

---

From: Zhen Cao <[email-masked]>
Date: Sun, 31 Oct 2010 23:37:19 +0800

> the requirement from ZigBee alliance may be one candidate.

Yes, I quoted the Zigbee profile which mandates the use of TCP. And
also if a stack does not support TCP, i do not think it is fully
capable.