Is there anyone have the average TCP response time for lwIP in GPRS enviroment?
I always meet the performance problem in lwIP+ PPP, and unable to clear where is the problem: CPU, GPRS Device or network environement. Recently I update to 1.3.1 lwIP
Here are some tests I made:
Use different PPP device: serial cable, CDMA device, BT SPP, the network performance become better, so CPU is not the problem for slow.
I create a DUN by our GPRS device, the TCP/IP performance is much better. Ping result: 800ms vs. 12xxms. Much faster TCP response time. GPRS network is not the problem for slow.
So I think the lwIP stack is the problem. But the most problem will be the paramters configuration.
Is there the sensitive paramters for quickent the TCP send and response.
Shorten the retransmit time, use TCP_NODELAY, quick ACK may help
I unable to known how to shorten the TCP retransmit time, and whether there is ACK delay.
Any suggestion is helpful.
Lee