I known the usage the TCP is nor properly. But I have no "right" to change the customer protocol.
The requriement is: one tcp connect is just for send, and response, the connection is disconnected. I could see the connect may take 2~3s in certain condition, the send and response will be about 2s. but the requirement is for finished the transaction with 5s. I do not knwon how to increase the lwIP performance in this condition. I use lwIP replace the platfrom TCP/IP, due to the original TCP/IP is design for lan, it has quick response but not stable in GRPS environment (lot of strange problems happened.) LwIP gives a stable performance. With the time out, the transaction speed requireemnt comes in. I could hardly trace in GPRS environement. I just trace in the server side, some time I could the data retransmit is very later. (50s). My test is simple echo server test. Is there any suggest so that i me do the fast transaction? Lee On Tue, Mar 31, 2009 at 11:41 PM, Kieran Mansley <[email protected]> wrote: > On Tue, 2009-03-31 at 23:28 +0800, yueyue papa wrote: > > How could I increase the TCP retransmit as quick as possible. The > > normal interact between server will be 1.4s ~ 2.5s. Some time the > > receive will be long than 20s, event to 50s. The interact is success, > > but it is extremely slow. > > Do you have a packet capture of this? 100 bytes taking 50s is rather > unusual: I would expect multiple cycles of loss and retransmission if > this is the case, and TCP backs off its sending rate (for good reason) > in these circumstances. > > Your suggestions are unlikely to help, and may make things worse or at > least have unintended side effects. TCP is quite cautious when it sees > loss as it interprets this as meaning the network is congested. There > have been some research projects over the years to modify TCP to make it > better at coping with environments like yours where loss is not due to > congestion, but lwIP doesn't have this sort of thing included. > > Probably the best solution if you require something that TCP isn't good > at is to use UDP, and layer your own protocol on top to deal with loss. > > Kieran > > > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users >
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