# HL76xx series TCP Keepalive

**URL:** https://forum.sierrawireless.com/t/hl76xx-series-tcp-keepalive/16089
**Category:** Legacy HL Series
**Created:** [April 17, 2019, 3:45am UTC](https://forum.sierrawireless.com/t/hl76xx-series-tcp-keepalive/16089 "2019-04-17T03:45:15Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![joshw](https://avatars.discourse-cdn.com/v4/letter/j/65b543/32.png) [@joshw](https://forum.sierrawireless.com/u/joshw)
#### Post date: [April 17, 2019, 3:45am UTC](https://forum.sierrawireless.com/t/hl76xx-series-tcp-keepalive/16089/1 "2019-04-17T03:45:15Z")

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Does anyone know a way of implementing a TCP keepalive when the module is setup as a TCP server?

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### Author: ![Sierra\_klin2](https://sea1.discourse-cdn.com/flex025/user_avatar/forum.sierrawireless.com/sierra_klin2/32/4769_2.png) [@Sierra\_klin2](https://forum.sierrawireless.com/u/Sierra_klin2)
#### Post date: [April 19, 2019, 8:26am UTC](https://forum.sierrawireless.com/t/hl76xx-series-tcp-keepalive/16089/2 "2019-04-19T08:26:56Z")

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HL76XX does not provide any AT interface for the TCP keepalive settings.  
Could you check if the TCP\_ACK could be useful in your case?

Syntax:  
AT+KTCPCFG=,,,\<tcp\_port\>,\<source\_port\>,\<data\_mode\>,,,\<cipher\_suite\>

 0 Do not display URC "+KTCP\_ACK" 1 Display URC "+KTCP\_ACK"