# tcp sockets on ppp problems

**URL:** <https://forums.digi.com/t/tcp-sockets-on-ppp-problems/10808>\
**Category:** Rabbit\
**Created:** [September 4, 2008, 6:51am UTC](https://forums.digi.com/t/tcp-sockets-on-ppp-problems/10808 "2008-09-04T06:51:50Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![ventunocm](https://avatars.discourse-cdn.com/v4/letter/v/34f0e0/32.png) [@ventunocm](https://forums.digi.com/u/ventunocm)\
**Post date:** [September 4, 2008, 6:51am UTC](https://forums.digi.com/t/tcp-sockets-on-ppp-problems/10808/1 "2008-09-04T06:51:50Z")

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Hi all, i’ve made a multi ppp system on LP3500 using ppplib and gprs modems

I’m now encountering a strange problem:  
at the first connection all works fine:

- ppp up and ip assigned
- socket connection to server ok
- bidirectional data transfer ok
- closing the fonnection by the server OK
- closing local socket
- closing ppp connection  
…  
…  
…  
…
- ppp up and ip assigned ( dinamically )
- socket connection does’nt establish

Any other had these problem?

There’s a way to flush tcp buffers and reinitialize tcp stacks and socket buffers?

Thanks to all.

Marco

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<div class="post-metadata">

**Author:** ![ventunocm](https://avatars.discourse-cdn.com/v4/letter/v/34f0e0/32.png) [@ventunocm](https://forums.digi.com/u/ventunocm)\
**Post date:** [September 8, 2008, 9:53am UTC](https://forums.digi.com/t/tcp-sockets-on-ppp-problems/10808/2 "2008-09-08T09:53:34Z")

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🙂

Hi all… i’ve solved the problem… it seems !!!

Every tcp ppp connection opening i call sock\_init();

and now it works fine!

Marco