Best Practice with multiple SBC's

[mhkdk]

Hi,

I have multiple Session Border Controllers connected to the same 3CX installation. In the 3CX SIP-Trunks / SBC settings there is a field for "First Audio (RTP) Port Number (Starting port is useful for QOS)" which is set to 20000 on every SBC, this seems to be the standard. I am curious if I have to change that port to give every SBC a unique range.

Background: The SBC's work fine for the most part, however we sometimes have calls that won't work properly. To narrow down the possible error I wanted to ask if this setting is important and how it should be configured in this scenario.

Thanks, Stefan.

 

[JohnS_3CX]

Hi Stefan,

This is the first audio port that the SBC will use when talking to a local phone.

Since each phone will talk to its own SBC, and the SBC can negotiate what ports it wants to use with its own assigned phones, then it should not matter at all and you should be able to use the same range on all SBCs

 

[mhkdk]

Hi John,

that makes a lot of sense. Thank you very much for the explanation. At least I can be somewhat sure this setting isn't responsible for the problems.

 

[JohnS_3CX]

If you face specific problems, you can start a new thread describing the issue and providing all the relevant information https://www.3cx.com/community/threads/information-to-provide-when-requesting-help.67558/