# Missing bytes in UDP rx packet

**URL:** <https://forum.sierrawireless.com/t/missing-bytes-in-udp-rx-packet/1695>\
**Category:** Open AT\
**Created:** [November 8, 2007, 6:37am UTC](https://forum.sierrawireless.com/t/missing-bytes-in-udp-rx-packet/1695 "2007-11-08T06:37:53Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![judith](https://avatars.discourse-cdn.com/v4/letter/j/d9b06d/32.png) [@judith](https://forum.sierrawireless.com/u/judith)\
**Post date:** [November 8, 2007, 6:37am UTC](https://forum.sierrawireless.com/t/missing-bytes-in-udp-rx-packet/1695/1 "2007-11-08T06:37:53Z")

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Hello!

I am trying to use WIP command to receive data by UDP. When I send “12345689” to my GSM module, GSM module can only rx the first 4 bytes data, followed by a special character of “black heart”.

UDP server sent: 123456789  
GSM module rx: 1234♥

Does anyone have idea on that?

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**Author:** ![tobias](https://avatars.discourse-cdn.com/v4/letter/t/c67d28/32.png) [@tobias](https://forum.sierrawireless.com/u/tobias)\
**Post date:** [November 8, 2007, 7:23am UTC](https://forum.sierrawireless.com/t/missing-bytes-in-udp-rx-packet/1695/2 "2007-11-08T07:23:52Z")

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If you send that as raw bytes it’s likely due to 4 being the EOT byte (End Of Transmission).

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**Author:** ![judith](https://avatars.discourse-cdn.com/v4/letter/j/d9b06d/32.png) [@judith](https://forum.sierrawireless.com/u/judith)\
**Post date:** [November 8, 2007, 8:48am UTC](https://forum.sierrawireless.com/t/missing-bytes-in-udp-rx-packet/1695/3 "2007-11-08T08:48:24Z")

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Hi tobias,

Whatever the UDP server tx, only the first 4 bytes are rx in the GSM module:

UDP server tx: abcdef  
GSM module rx: abcd♥

Thus, I don’t think the character “4” is the EOT byte.

Judith

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**Author:** ![tobias](https://avatars.discourse-cdn.com/v4/letter/t/c67d28/32.png) [@tobias](https://forum.sierrawireless.com/u/tobias)\
**Post date:** [November 8, 2007, 9:04am UTC](https://forum.sierrawireless.com/t/missing-bytes-in-udp-rx-packet/1695/4 "2007-11-08T09:04:03Z")

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Could you describe what commands you use on the modem to set it up for UDP reception as well as what firmware version you use for both the modem and wipsoft. (ATI3 and AT+WIPCFG=3)

Only the commands from AT+WIPCREATE… are interesting.

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**Author:** ![judith](https://avatars.discourse-cdn.com/v4/letter/j/d9b06d/32.png) [@judith](https://forum.sierrawireless.com/u/judith)\
**Post date:** [November 9, 2007, 1:49am UTC](https://forum.sierrawireless.com/t/missing-bytes-in-udp-rx-packet/1695/5 "2007-11-09T01:49:27Z")

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Hi tobias,

firware version:  
ati3  
657\_09gg.Q24PL001 1954500 102706 18:44

wipsoft version:   
at+wipcfg=3  
WIP Soft v201 on Open AT OS v312

Command I used to set up UDP reception in the GSM modem:  
at+wipcfg=1  
OK  
at+wipbr=1,6  
OK  
at+wipbr=2,6,11,“[peoples.net](http://peoples.net)”  
OK  
at+wipbr=4,6,0   
OK  
at+wipcreate=1,1,5000,“xxx.yyy.zzz.lll”,5000 // xxx.yyy.zzz.lll is the IP address of the UDP server  
OK

+WIPREADY: 1, 1  
AT+WIPDATA=1,1,1  
CONNECT  
abcd♥

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**Author:** ![tobias](https://avatars.discourse-cdn.com/v4/letter/t/c67d28/32.png) [@tobias](https://forum.sierrawireless.com/u/tobias)\
**Post date:** [November 9, 2007, 8:10am UTC](https://forum.sierrawireless.com/t/missing-bytes-in-udp-rx-packet/1695/6 "2007-11-09T08:10:22Z")

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I suggest that you first talk to your distributor so you can get a newer version of WIPSoft (the latest I know of is 3.01) and do the tests again.  
And make sure your distributor gives you 3.10 when it is released (should be in december) as that fixes additional bugs when working with UDP.