Hi bruce
My project is build above lpc2365 (the same ram size)
I reserved 6k for emac dma driver (3k for tx, 3k for rx).
I used other ram available in ethernet ram for allocation of buffers for application related to uarts (0 and 2) manager and tcp manager and udp manager and for a task which acts as protocol converter (we are using proprietary protocols)
I tried my code with some test software build myself, to test throughput . I haven't a value for you, because my goal was only try to stress the application fw, because in real situation our chain (pc app, ip board, serial device) works using halfduplex communication (send a packet and wait for answer) and serial device cannot work with a speed greater than 115200.
Anyway, i attached my lwipots.h file
we can discuss about it, here.
Bye,
Piero
2008/10/14 Bruce Sutherland
<address@hidden>
Hi everyone.
We are using lwip on an embedded target (LPC2368 microcontroller).
We have successfully used lwip to act as a serial device server. That is to
say, we accept data via a TCP connection on an Ethernet link, and transmit
the data out on an RS-232 serial port.
Now, our goal is to maximize throughput over the link. My impression is that
maximum TCP throughput is limited by lwip configuration options. These
options are mostly constrained by the available memory. This means that
maximum throughput is some function of memory size, capped by any other
bottlenecks in a system, something like this:
http://er6australia.com/images/tcp_thruput_vs_memory.png
My question is: given a certain amount of free RAM, how should lwip options
be configured for best throughput?
Say for example, we have 10 kb of RAM available for lwip to use. How should
we set options such as MEM_SIZE, MEMP_SANITY_CHECK, MEMP_OVERFLOW_CHECK,
TCP_WND, TCP_QUEUE_OOSEQ, TCP_MSS and so on? I know this is quite a broad
question. Links to discussions of this subject would be welcomed.
Regards,
Bruce.
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lwipopts.h