# How to enable TLS encryption on Grandstream phone
### What is TLS?
**TLS** is a cryptographic protocol that secures/encrypts SIP messages sent by a softphone, IP phone, or a PBX
This protocol offers a series of advantages, some of those advantages are:
* With TLS enabled, SIP messages cannot be intercepted, read, or altered by intruding parties;
* TLS is a recognized cryptography standard that allows you to use VoIP on the majority of mobile networks where you would otherwise encounter connectivity issues, or be unable to establish a connection with VoIP at all due to firewalls
* Enabling TLS in SIP-based IP-Phones can also help alleviate some issues that you may encounter with NAT transversal issues that often occur on double-NAT’d networks such as 4G/LTE networks.
### Important Notes / Requirements
For this guide you will only need access to a SIP Phone, this guide uses a GXP2170 as an example.
{% hint style="info" %}
Note: This TLS encryption are also tested on GRP Phones (GRP2615 and GRP2613) models
If you are using GRP Phones no need to follow Step 4 and 5 since it was set to Unlimted by default
{% endhint %}
### Configuring TLS on a Grandstream GXP2170
For this example, we will be using a Grandstream GXP2170, but the general concept is the same for the majority of SIP-based IP phones.
The majority of SIP-based IP phones should support the use of TLS for the transport protocol, but some may require additional settings to be enabled for it to work.
### Steps
Follow the steps below to configure the TLS connection on the Grandstream GXP2170
1. Log in to the Grandstream phone
2. Navigate to “Accounts > Account 1 > SIP Settings > Basic settings”
3\. Change the SIP Transport parameter from “UDP” to “TLS/TCP” to activate the TLS protocol then click "Save & Apply" at the bottom of the page
{% hint style="info" %}
These next steps don't apply to the GRP series phones, if you have a GRP Series phone you don't need to complete steps 4 and 5
{% endhint %}
4\. Navigate to "Maintenance >> Security Settings >> Security"
5\. Change the “Minimum TLS Version” from "TLS 1.1" to "TLS 1.0" then click "Save & Apply" at the bottom of the page
Congratulation you have successfully configured your Grandstream phone to use TLS protocol for encryption
Make sure to do a test call inbound/outbound from the phone as well to confirm everything is working smoothly, some phones may require slightly different configuration settings.
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