# TCP error -991 WIP\_CERR\_PORT\_IN\_USE

**URL:** <https://forum.sierrawireless.com/t/tcp-error-991-wip-cerr-port-in-use/3998>\
**Category:** Open AT\
**Created:** [December 17, 2009, 11:02am UTC](https://forum.sierrawireless.com/t/tcp-error-991-wip-cerr-port-in-use/3998 "2009-12-17T11:02:52Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![CesaroniN](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@CesaroniN](https://forum.sierrawireless.com/u/CesaroniN)\
**Post date:** [December 17, 2009, 11:02am UTC](https://forum.sierrawireless.com/t/tcp-error-991-wip-cerr-port-in-use/3998/1 "2009-12-17T11:02:52Z")

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Hi all,  
I’m using Fastrack 20 (R74\_00gg.FSU005) with ethernet board  
I can use only one local tcp port to go on internet through a firewall, then I use the WIP\_COPT\_PORT parameter on open the TCP channel with the specified port (wip\_TCPClientCreateOpts) .  
First time everything work well. The client is created and data are trasmitted.  
After closing the channel with wip\_close function (I also use the finalizer callback function), subsequent calls to the function wip\_TCPClientCreateOpts return a valid Channel but the event handler function return immediately a -991 error : WIP\_CERR\_PORT\_IN\_USE.  
The manual says that with wip\_Close all resources are freed.

Any ideas ?  
Thanks  
Nicola

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<div class="post-metadata">

**Author:** ![CesaroniN](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@CesaroniN](https://forum.sierrawireless.com/u/CesaroniN)\
**Post date:** [December 17, 2009, 6:26pm UTC](https://forum.sierrawireless.com/t/tcp-error-991-wip-cerr-port-in-use/3998/2 "2009-12-17T18:26:19Z")

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An update: after about 5 minutes, the port is released by the system and can be reused …

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**Author:** ![Madouc](https://avatars.discourse-cdn.com/v4/letter/m/b782af/32.png) [@Madouc](https://forum.sierrawireless.com/u/Madouc)\
**Post date:** [December 19, 2009, 11:26am UTC](https://forum.sierrawireless.com/t/tcp-error-991-wip-cerr-port-in-use/3998/3 "2009-12-19T11:26:24Z")

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does this also happen if you restart (eg close, wait for event and then start) the bearer?

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<div class="post-metadata">

**Author:** ![CesaroniN](https://avatars.discourse-cdn.com/v4/letter/c/c68b51/32.png) [@CesaroniN](https://forum.sierrawireless.com/u/CesaroniN)\
**Post date:** [December 21, 2009, 6:07pm UTC](https://forum.sierrawireless.com/t/tcp-error-991-wip-cerr-port-in-use/3998/4 "2009-12-21T18:07:15Z")

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If I restart the bearer the port is free, but with my application I can’ t close the bearer; I need to make some concurrent connection .