Re: [lwip-users] socket option TCP_NODELAY: not implemented???

[Piero 74]

Sorry... i only check the code... i didn't understand how code works.... after your post i checked again... i will try to disable nagle alg.

Do you think usefull disable it if want short delay in packet exchange between pc application and lwip board? band is not a problem (packet will have size <600 bytes)
For the same reason (time performance), i'm thinking to use MSG_MORE flag in send function... do you think that i could have some strange problem?

And the last question:
i used setting above for lwip, and i obtained a very good performance using a simple test. Do you think are they correct?


#define TCP_MSS                         1460
#define TCP_SND_BUF                     (TCP_MSS<<1)
#define PBUF_POOL_BUFSIZE               LWIP_MEM_ALIGN_SIZE(128)
#define PBUF_POOL_SIZE                  20

#define IP_OPTIONS_ALLOWED              1

#define IP_REASSEMBLY                   1
#define IP_FRAG                         0

the last two setting, follows this my idea:
i used a big MSS and a MTU ot 1536. If pc application send packet to my lwip board throght different routers, or internet connection, it could possible that path mtu will be smaller than my MTU, and IP packets will be fragmented, so, lwip needs to reassemble packets. packets transmitted from lwip board will be not fragmented and will have maximum size of 1536.
What do you think?

Thanks, bye,
Piero

2008/3/10, Jonathan Larmour <address@hidden>:

Piero 74 wrote:
> Hi.
>
> I want to try to disable nagle alg. I saw  in lwip_setsockopt_internal
> function that it's possible to use TCP_NODELAY option, but this option
> seems unimplemented in lwip_setsockopt
>
> does someone explain me how i can use this option??


It is implemented. How are you calling setsockopt?

Jifl
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