# Connecting to cluster problem

**URL:** <https://community.hivemq.com/t/connecting-to-cluster-problem/1805>\
**Category:** HiveMQ Cloud\
**Created:** [February 3, 2023, 8:42pm UTC](https://community.hivemq.com/t/connecting-to-cluster-problem/1805 "2023-02-03T20:42:02Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![eyelessjack](https://avatars.discourse-cdn.com/v4/letter/e/bb73d2/32.png) [@eyelessjack](https://community.hivemq.com/u/eyelessjack)\
**Post date:** [February 3, 2023, 8:42pm UTC](https://community.hivemq.com/t/connecting-to-cluster-problem/1805/1 "2023-02-03T20:42:02Z")

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Hi,

I’m trying to connect to my own cluster using an embedded system that uses a SIM800C. This component works with AT commands.

To start the connection I’m using AT+CIPSTART=“TCP”,“xxxxxxx.s2.eu.hivemq.cloud”,8883  
where the first address is found on “Manage cluster —\> Host Name”.  
With this command I can not estabilish the connection.  
If I try to estabilish the connection with an other custom server everything goes ok.

I’m using AT+CIPSTART=“TCP”,“…cloud”,“8883” but I can’t connect. I need to enter a username and password to connect, but there is no field to enter them in the AT+CIPSTART command. How can I solve my problem. I have no problem connecting to the public server, but I have a problem with the cloud server.

Thanks,

 ![Screenshot 2023-02-03 233916](https://canada1.discourse-cdn.com/flex035/uploads/hivemq1/original/1X/5047fe9c292277b88cfdfb25082b1a168a00a5b9.png)

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**Author:** ![Daria\_H](https://avatars.discourse-cdn.com/v4/letter/d/dfb087/32.png) [@Daria\_H](https://community.hivemq.com/u/Daria_H)\
**Post date:** [February 7, 2023, 9:49am UTC](https://community.hivemq.com/t/connecting-to-cluster-problem/1805/2 "2023-02-07T09:49:40Z")

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Hi @eyelessjack ,

Great to see your interest in MQTT and HiveMQ, welcome to the community!

For HiveMQ cloud we require the [TLS-SNI extension](https://en.wikipedia.org/wiki/Server_Name_Indication) to be available and used by your device. Can you confirm that SIM800C module supports [Server Name Indication (SNI)](https://en.wikipedia.org/wiki/Server_Name_Indication)?

I hope this helps.  
Kind regards,  
Dasha from HiveMQ Team