How to Secure Your VoIP Phone Calls with the GXP Phones and UCM6200

June 21, 2018 by Ying-Hui Chen

Grandstream UCM IP PBX and GXP VoIP Phones are some of the hottest products VoIP Supply carries. In our latest webinar with Grandstream, we had over 100 participants join us to learn about how to secure VoIP phone calls with Grandstream’s GXP phones and UCM6200.

To make sure you get the most out of this webinar, we’d like to share the presentation slides and the Q&A session with all of you who are interested in learning more!

Click here to download the presentation deck

How to Secure Your VoIP Phone Calls Webinar Q&A Session

Question 1: Why is the TLS Do Not Verify is checked under SIP Settings> TCP/TLS tab? I thought TLS requires TCP?

Answer: TLS runs on TCP for sure. This option is for people who want to run SIP on TCP without TLS. When you enable TLS, it automatically runs on TCP. So even when you have “TLS Enable” checked and leave “TCP Enable” unchecked, it doesn’t mean that TCP is not being used, it IS being used. It’s just another option to enable TCP without TLS.


Question 2: How can we download the certificates from the UCM in order to import them to the GXP phones?

Answer: Those are built into UCM. If you have any issues, contact us and we will send you those certificates. You can then upload them to your UCM IP PBX or GXP phones.


Question 3: How about the SIP URI Scheme when using TLS? Should it be active or not when using TLS?

Answer: Yes, It’s enabled by default.


Question 4: If someone is trying to register an extension on the UCM from the outside, can they be blocked?

Answer: When you enable TLS, even if you have devices that don’t support TLS, they can still register to the UCM. If the devices are using plain text SIP protocol to register to the UCM, they will still be able to register even if TLS is enabled.


Question 5: Is the TLS.key field for the Private Certificate?

Exactly. That’s correct. That is the private key. If you have the name private key, you have to the TLS.key


Have more questions? Don’t hesitate to contact our VoIP consultant, Jon Garbin, at [email protected] or 716-531-4271!

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