Re: [lwip-commits] lwip

[Jani Monoses]

On Tue, 23 Sep 2003 14:25:56 +0200
"Amit Kristal" <address@hidden> wrote:

> Hi all,
> 
> I have just started looking at the lwip & I have a few Questions:
> 
> 1. Does lwip support "reassembly"(a TCP packet that spreads over a few
> ethernet packets) ?

Yes, although the IP reassembly code could use some rework as it uses to
much memory.

> 2. I would like to work with the raw api, does it mean that I should
> use tcp.c & not use the api directory
>    (api_msg.c, api_lib.c, sockets.c, tcpip.c)?

Yes.

> 3. Which files in the app directory demonstrate the use of the raw
> api? is it only the httpd.c file?

I think only httpd.c, yes. 

> 4. Regarding the lwip heap memory:
>    a. Why Does the MEM_SIZE is only set to 1000, isn't it a bit small?
The default options are not tuned for any application, they need to be
set according to specific needs. Yes for most apps this mem size is too
small.

>    b. Can you give a rough estimation about the MEM_SIZE when I have
>    100Kbit 
> in & 100Kbit out?
Not really, but the other values play an important  role in the
troughput as well, like the pbuf memory size, TCP window sizes etc.
Experiment with them.

>    c. Does the "ram[MEM_ALIGN_SIZE(MEM_SIZE + sizeof(struct mem))];"
>    is all 
> the heap memory used
>       by the lwip?

Yes, other memories are statically allocated. But so is this heap
itself.
Jani