SIP OPTIONS Support

[eddv123]

Does anyone know the status for SIP OPTIONS support with 3CX. The below post is very old now but wanted to know if the situation was still the case:
https://www.3cx.com/community/threads/sip-option-message.2208/

Calls were failing up until the point of the provider (in their words) disabled SIP OPTIONS on their side (but have said the only want to do this as a temporary work around) until we investigate our side (3CX) as soon as this was configured however calls worked straight away.

The provider is un-supported as the customer is based in Hong Kong and they are doing some sort of SIP Connect through TATA.

I have never come across this issue before as we normally always use 3CX Supported providers so any feedback from the community would be greatly appreciated.

 

[NickD_3CX]

Hi!

So the current status is that 3CX will respond to SIP OPTIONS messages blindly with a 200 OK. We have many supported providers that do this and I have seen it work.
Some providers do this to monitor if the PBX is still online.

What we can't currently do is the 3CX generate SIP OPTIONS as a keep-alive method.

I had run into a case some months ago where a provider was sending SIP OPTIONS and 3CX was not responding. It turned out in that the SIP OPTIONS format was wrong and was being ignored by our SIP engine.
If memory serves, the line breaks in of the SIP message had LF linebreaks (Linux style) instead of CRLF (Windows style) and at the end of the message their was not CRLF (a blank line), which I believe is required for these messages that don't have an SDP.

Don't know if this is the case, but maybe worth checking out.