Hi, Thank You all for your very good input. I was able to get my packet size up to 2500 bytes which Should be good for what I am trying to do. My Xilinx board will only be hooked to a PC so The extra long packets will not be affected by network components. If interested I have a thread At Xilinx website you could take a look at.
http://forums.xilinx.com/xlnx/board/message?board.id=EDK&thread.id=4361 and there is a second thread I created earlier about PBUF length that is no longer a problem since I increased the size of my packets to 2500 bytes in UDP transfers. Thanks, Gary Olson -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Thursday, August 07, 2008 12:00 PM To: [email protected] Subject: lwip-users Digest, Vol 60, Issue 3 Importance: Low Send lwip-users mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit http://lists.nongnu.org/mailman/listinfo/lwip-users or, via email, send a message with subject or body 'help' to [EMAIL PROTECTED] You can reach the person managing the list at [EMAIL PROTECTED] When replying, please edit your Subject line so it is more specific than "Re: Contents of lwip-users digest..." Today's Topics: 1. Xilinx Board LWIP UDP Packet Length limitation (Gary Olson) 2. Re: Xilinx Board LWIP UDP Packet Length limitation ([EMAIL PROTECTED]) 3. RE: Xilinx Board LWIP UDP Packet Length limitation (Bill Auerbach) ---------------------------------------------------------------------- Message: 1 Date: Wed, 6 Aug 2008 13:37:36 -0400 From: "Gary Olson" <[EMAIL PROTECTED]> Subject: [lwip-users] Xilinx Board LWIP UDP Packet Length limitation To: <[email protected]> Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="us-ascii" Hi, I am working with Xilinx EDK and LWIP I think it is version 1.2. I am able to use the uecho test to send UDP packets less that length 1460 bytes or so. But when I try to increase the UDP Packet length to 2000 it fails. My desire is to at least be able to send packets that are 2500 bytes in length. This is because I am trying to send a whole packet of data with the length of one packet to be about 2020 bytes maximum. I tried increasing the TCP_MSS value from 1460 to 3000 (in the lwip software settings). This did not make it work however. Does anyone know what I can do to send larger packets using LWIP. Thank You, Gary Olson -------------- next part -------------- An HTML attachment was scrubbed... URL: http://lists.gnu.org/pipermail/lwip-users/attachments/20080806/1c174c0f/atta chment.html ------------------------------ Message: 2 Date: Wed, 06 Aug 2008 22:33:24 +0200 From: "[EMAIL PROTECTED]" <[EMAIL PROTECTED]> Subject: Re: [lwip-users] Xilinx Board LWIP UDP Packet Length limitation To: Mailing list for lwIP users <[email protected]> Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset=ISO-8859-1; format=flowed I don't have experience with ethernet packets bigger than1514 bytes, but I think the main limitations are: - netif->mtu (you have to set this when initializing the netif) - TCP_MSS (as you already have discovered) - IP fragmentation: either turn it off (define IP_FRAG to 0) or set IP_FRAG_MAX_MTU higher than its default (1500) there may be more though... Simon Gary Olson wrote: > > Hi, > > I am working with Xilinx EDK and LWIP I think it is version 1.2. I > am able to use the uecho test to send UDP packets less that length > 1460 bytes or so. > > But when I try to increase the UDP Packet length to 2000 it fails. > My desire is to at least be able to send packets that are > > 2500 bytes in length. This is because I am trying to send a whole > packet of data with the length of one packet to be about 2020 bytes > maximum. > > > > > > I tried increasing the TCP_MSS value from 1460 to 3000 (in the lwip > software settings). This did not make it work however. > > > > Does anyone know what I can do to send larger packets using LWIP. > > > > Thank You, > > Gary Olson > > > > ------------------------------------------------------------------------ > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users ------------------------------ Message: 3 Date: Wed, 6 Aug 2008 18:08:28 -0400 From: "Bill Auerbach" <[EMAIL PROTECTED]> Subject: RE: [lwip-users] Xilinx Board LWIP UDP Packet Length limitation To: "'Mailing list for lwIP users'" <[email protected]> Message-ID: <[EMAIL PROTECTED]> Content-Type: text/plain; charset="us-ascii" > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] On > Behalf Of [EMAIL PROTECTED] > Sent: Wednesday, August 06, 2008 4:33 PM > To: Mailing list for lwIP users > Subject: Re: [lwip-users] Xilinx Board LWIP UDP Packet Length > limitation > > I don't have experience with ethernet packets bigger than1514 bytes, > but > I think the main limitations are: > - netif->mtu (you have to set this when initializing the netif) > - TCP_MSS (as you already have discovered) > - IP fragmentation: either turn it off (define IP_FRAG to 0) or set > IP_FRAG_MAX_MTU higher than its default (1500) > > there may be more though... You have to be sure all devices on the switch are Jumbo Frame enabled too. 2 packets come in back to back within microseconds of each other. I don't really think there is any significant benefit to large frames. In our application using them improved bandwidth a negligible amount. We don't want network compatibility issues or requirements for Jumbo Frame supporting hardware to be installed to work with our device, so we stuck with the industry standard normal packet size. Bill ------------------------------ _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users End of lwip-users Digest, Vol 60, Issue 3 ***************************************** _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
