# Boron 3G, DeviceOS 6.3.4, periodic 3G modem freezes and lose of connection. ERROR: The other end has not replied to keep alives (TESTs) 5 times

**URL:** <https://community.particle.io/t/boron-3g-deviceos-6-3-4-periodic-3g-modem-freezes-and-lose-of-connection-error-the-other-end-has-not-replied-to-keep-alives-tests-5-times/70934>\
**Category:** Connectivity\
**Tags:** boron\
**Created:** [January 22, 2026, 2:07pm UTC](https://community.particle.io/t/boron-3g-deviceos-6-3-4-periodic-3g-modem-freezes-and-lose-of-connection-error-the-other-end-has-not-replied-to-keep-alives-tests-5-times/70934 "2026-01-22T14:07:31Z")\
**Posts on this page:** 6\
**Page:** 1

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**Author:** ![abovyan](https://avatars.discourse-cdn.com/v4/letter/a/54ee81/32.png) [@abovyan](https://community.particle.io/u/abovyan)\
**Post date:** [January 22, 2026, 2:07pm UTC](https://community.particle.io/t/boron-3g-deviceos-6-3-4-periodic-3g-modem-freezes-and-lose-of-connection-error-the-other-end-has-not-replied-to-keep-alives-tests-5-times/70934/1 "2026-01-22T14:07:31Z")

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Hi everybody!

Recently I started getting this errors on two Borons. Looking at the empty project trace I see that it is not a application software problem. The firmware does 1 sec periodic check of RSI only. As I can see aproximately after 20-30 secs after succesfully conencting to 3G and Particle cloud mode freezes at:

0003393882 [ncp.at] TRACE: \> AT+COPS=3,2  
0003436327 [mux] ERROR: The other end has not replied to keep alives (TESTs) 5 times, considering muxed connection dead

And the it resets the modem. Everything goes by this cycle afterwards. Boron is battery powered + AC adpter powered and it reports correct 4.1V battery voltage. Is anybody aware of such a problem?

Great thanks in advance

…

0003380144 [net.ppp.client] TRACE: State CONNECTING -\> CONNECTED  
0003380144 [system.nm] INFO: State changed: IFACE\_LINK\_UP -\> IP\_CONFIGURED  
0003380146 [net.pppncp] TRACE: Negotiated MTU: 1500  
0003380146 [net.ppp.client] TRACE: PPP phase -\> Running  
0003380174 [comm.coap] TRACE: Sending CoAP message  
0003380175 [comm.coap] TRACE: CON 0.00 size=4 token= id=68  
0003380691 [ncp.at] TRACE: \> AT+COPS=3,2  
0003380694 [ncp.at] TRACE: \< OK  
0003380695 [ncp.at] TRACE: \> AT+COPS?  
0003380698 [ncp.at] TRACE: \< +COPS: 0,2,"28301",2  
0003380698 [ncp.at] TRACE: \< OK  
0003380699 [ncp.at] TRACE: \> AT+CSQ  
0003380702 [ncp.at] TRACE: \< +CSQ: 21,2  
0003380702 [ncp.at] TRACE: \< OK  
Strength: -66.00 dBm (100.00) Quality: -6.00 (70.00)  
0003381003 [comm.coap] TRACE: Received CoAP message  
0003381003 [comm.coap] TRACE: ACK 0.00 size=4 token= id=68  
0003381705 [ncp.at] TRACE: \> AT+COPS=3,2  
0003381707 [ncp.at] TRACE: \< OK  
0003381708 [ncp.at] TRACE: \> AT+COPS?  
0003381711 [ncp.at] TRACE: \< +COPS: 0,2,"28301",2  
0003381712 [ncp.at] TRACE: \< OK  
0003381713 [ncp.at] TRACE: \> AT+CSQ  
0003381715 [ncp.at] TRACE: \< +CSQ: 21,2  
0003381716 [ncp.at] TRACE: \< OK  
Strength: -66.00 dBm (100.00) Quality: -6.00 (70.00)  
0003382718 [ncp.at] TRACE: \> AT+COPS=3,2  
0003382721 [ncp.at] TRACE: \< OK  
0003382721 [ncp.at] TRACE: \> AT+COPS?  
0003382725 [ncp.at] TRACE: \< +COPS: 0,2,"28301",2  
0003382725 [ncp.at] TRACE: \< OK  
0003382726 [ncp.at] TRACE: \> AT+CSQ  
0003382729 [ncp.at] TRACE: \< +CSQ: 22,2  
0003382730 [ncp.at] TRACE: \< OK

…  
0003391840 [ncp.at] TRACE: \> AT+COPS=3,2  
0003391843 [ncp.at] TRACE: \< OK  
0003391844 [ncp.at] TRACE: \> AT+COPS?  
0003391847 [ncp.at] TRACE: \< +COPS: 0,2,"28301",2  
0003391847 [ncp.at] TRACE: \< OK  
0003391848 [ncp.at] TRACE: \> AT+CSQ  
0003391851 [ncp.at] TRACE: \< +CSQ: 20,2  
0003391851 [ncp.at] TRACE: \< OK  
Strength: -68.00 dBm (100.00) Quality: -6.00 (70.00)  
0003392854 [ncp.at] TRACE: \> AT+COPS=3,2  
0003392856 [ncp.at] TRACE: \< OK  
0003392857 [ncp.at] TRACE: \> AT+COPS?  
0003392860 [ncp.at] TRACE: \< +COPS: 0,2,"28301",2  
0003392861 [ncp.at] TRACE: \< OK  
0003392862 [ncp.at] TRACE: \> AT+CSQ  
0003392880 [ncp.at] TRACE: \< +CSQ: 21,2  
0003392880 [ncp.at] TRACE: \< OK  
Strength: -66.00 dBm (100.00) Quality: -6.00 (70.00)  
0003393882 [ncp.at] TRACE: \> AT+COPS=3,2  
0003436327 [mux] ERROR: The other end has not replied to keep alives (TESTs) 5 times, considering muxed connection dead  
0003436328 [ncp.client] TRACE: NCP connection state changed: 1  
0003436328 [net.pppncp] TRACE: NCP event 2  
0003436329 [net.pppncp] TRACE: State changed event: 1  
0003436329 [mux] INFO: GSM07.10 muxer thread exiting  
0003436330 [net.ppp.client] TRACE: PPP thread event LOWER\_DOWN data=0  
0003436331 [net.ppp.client] TRACE: State CONNECTED -\> DISCONNECT

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<div class="post-metadata">

**Author:** ![rickkas7](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/rickkas7/32/8681_2.png) [@rickkas7](https://community.particle.io/u/rickkas7)\
**Post date:** [January 22, 2026, 2:26pm UTC](https://community.particle.io/t/boron-3g-deviceos-6-3-4-periodic-3g-modem-freezes-and-lose-of-connection-error-the-other-end-has-not-replied-to-keep-alives-tests-5-times/70934/2 "2026-01-22T14:26:06Z")

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Is this a BRN310 or BRN314? They have different SIM cards and it could be an issue between the SIM provider and the local operator ArmenTel/Beeline Armenia (28301).

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**Author:** ![abovyan](https://avatars.discourse-cdn.com/v4/letter/a/54ee81/32.png) [@abovyan](https://community.particle.io/u/abovyan)\
**Post date:** [January 23, 2026, 1:34pm UTC](https://community.particle.io/t/boron-3g-deviceos-6-3-4-periodic-3g-modem-freezes-and-lose-of-connection-error-the-other-end-has-not-replied-to-keep-alives-tests-5-times/70934/3 "2026-01-23T13:34:37Z")

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Thanks for a response!

Its BRN314 (so with EtherSIM) and it was working for 2 years without any problem. It started just recently and it drives me mad that I can`t figure out what is the problem. Do you have any suggestions in mind?

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<div class="post-metadata">

**Author:** ![rickkas7](https://sea2.discourse-cdn.com/flex026/user_avatar/community.particle.io/rickkas7/32/8681_2.png) [@rickkas7](https://community.particle.io/u/rickkas7)\
**Post date:** [January 23, 2026, 1:53pm UTC](https://community.particle.io/t/boron-3g-deviceos-6-3-4-periodic-3g-modem-freezes-and-lose-of-connection-error-the-other-end-has-not-replied-to-keep-alives-tests-5-times/70934/4 "2026-01-23T13:53:58Z")

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Not sure. It's not a known issue.

This error

```auto
0003436327 [mux] ERROR: The other end has not replied to keep alives (TESTs) 5 times, considering muxed connection dead

```

can occur if the cellular modem has crashed. Does it start working again if you remove power (and battery) from the device?

The modem should fully reset after 10 minutes of failing to connect, but it could be an unknown/unexpected condition.

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<div class="post-metadata">

**Author:** ![abovyan](https://avatars.discourse-cdn.com/v4/letter/a/54ee81/32.png) [@abovyan](https://community.particle.io/u/abovyan)\
**Post date:** [January 23, 2026, 2:09pm UTC](https://community.particle.io/t/boron-3g-deviceos-6-3-4-periodic-3g-modem-freezes-and-lose-of-connection-error-the-other-end-has-not-replied-to-keep-alives-tests-5-times/70934/5 "2026-01-23T14:09:47Z")

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Yeah, it freezes then automatically restarts. And this loop continues forever. Sometimes it is enough time to update the firmware from the Cloud, sometimes not…

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<div class="post-metadata">

**Author:** ![system](https://us1.discourse-cdn.com/flex026/uploads/particle/original/3X/3/2/3291e3c9351789fe8620ae5bcec8d3fec67ff221.png) [@system](https://community.particle.io/u/system)\
**Post date:** [July 25, 2026, 2:10am UTC](https://community.particle.io/t/boron-3g-deviceos-6-3-4-periodic-3g-modem-freezes-and-lose-of-connection-error-the-other-end-has-not-replied-to-keep-alives-tests-5-times/70934/6 "2026-07-25T02:10:43Z")

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