Re: High packet rate ethernet with LwIP

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.arch.embedded
Subject	Re: High packet rate ethernet with LwIP
Date	2019-09-23 23:08 +0200
Organization	A noiseless patient Spider
Message-ID	<qmbc7i$b2f$1@dont-email.me> (permalink)
References	<nnd$46f32a8f$5fab99bf@bacadb246ebd9154> <f75aoe97bvj84fdfhp80376p9k1o1vm55v@4ax.com> <nnd$385a4f2f$5a6cc64f@f248034e4c3a4bf9> <a55ioedac35imcob1lv1962hu7o4hhmnh1@4ax.com> <nnd$6c8857a3$157fdc33@3c0b08fe0107a828>

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On 23/09/2019 22:16, Stef wrote:
> On 2019-09-23 upsidedown@downunder.com wrote in comp.arch.embedded:
>> On Mon, 23 Sep 2019 10:37:17 +0200, Stef
>> <stef33d@yahooI-N-V-A-L-I-D.com.invalid> wrote:
>>
<snip>
>>> Missing packets may not be a problem. It is measurement data and if
>>> any re-transmit takes over 40 ms there is no point anyway, there is
>>> already new data.
>>
>> Just make sure you know if some frames are missing (e.g. serial
>> numbering).
> 
> Yes, we need something to detect missing packets.
> 
>>> On a much slower rate, some control connection does
>>> have to be reliable. So that could use TCP (if is does not disturb
>>> the parallel UDP flow in LwIP) or use UDP as well and implement the
>>> retries in the application.
>>
>> Why not, you can use both TCP and UDP as two separate links, even with
>> the same IP-address and port number.
> 
> Yes, that is true, but does LwIP support this? I don't know how the
> final output to the MAC is treated, so in a (dumb) implementation, a TCP
> retransmission could hold up everything. Not that I expect this from LwIP
> (as it is widely used), but it is something to check.
> 

UDP and TCP/IP are independent - so there is no problem for a server to 
have UDP port 1234 and TCP/IP port 1234 open and active at the same time.

For the client side of the connection, the network stack picks a 
different source port for each connection.  So the client end can have 
as many connections (UDP, TCP/IP, both) as it wants connected to the 
same destination port at the server side.

Thread

High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-20 18:27 +0200
  Re: High packet rate ethernet with LwIP upsidedown@downunder.com - 2019-09-20 21:20 +0300
    Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-23 10:37 +0200
      Re: High packet rate ethernet with LwIP Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2019-09-23 14:08 +0300
      Re: High packet rate ethernet with LwIP Richard Damon <Richard@Damon-Family.org> - 2019-09-23 07:13 -0400
        Re: High packet rate ethernet with LwIP Tauno Voipio <tauno.voipio@notused.fi.invalid> - 2019-09-23 18:55 +0300
      Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-23 14:04 +0200
        Re: High packet rate ethernet with LwIP Dimiter_Popoff <dp@tgi-sci.com> - 2019-09-23 17:03 +0300
          Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-23 18:37 +0200
            Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-24 14:22 +0200
              Re: High packet rate ethernet with LwIP upsidedown@downunder.com - 2019-09-25 07:55 +0300
                Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-25 09:51 +0200
                Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-25 16:03 +0200
                Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-25 11:59 +0200
                Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-25 13:16 +0200
              Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-25 09:42 +0200
                Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-25 13:41 +0200
                Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-25 14:10 +0200
                Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-25 15:22 +0200
      Re: High packet rate ethernet with LwIP upsidedown@downunder.com - 2019-09-23 22:26 +0300
        Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-23 22:16 +0200
          Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-23 23:08 +0200
  Re: High packet rate ethernet with LwIP Joe Chisolm <jchisolm6@earthlink.net> - 2019-09-20 13:44 -0500
    Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-23 10:46 +0200
  Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-21 19:00 +0200
    Re: High packet rate ethernet with LwIP upsidedown@downunder.com - 2019-09-22 00:01 +0300
      Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-22 09:06 +0200
        Re: High packet rate ethernet with LwIP upsidedown@downunder.com - 2019-09-22 11:29 +0300
          Re: High packet rate ethernet with LwIP David Brown <david.brown@hesbynett.no> - 2019-09-22 23:24 +0200
        Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-23 11:10 +0200
    Re: High packet rate ethernet with LwIP Stef <stef33d@yahooI-N-V-A-L-I-D.com.invalid> - 2019-09-23 11:03 +0200

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