On Jun 1, 2016, at 4:05 PM, Oleg Stolyar <olegstolyar@gmail.com> wrote:

Thanks guys!  IP tables is how we block most traffic but we can only block traffic by port.  In this case it's about invalid INVITES coming in on a valid port.

Do you think this functionality would be useful?  

Is it worth opening a feature request and perhaps putting a bounty on it?  

Any idea of the effort?

On Wed, Jun 1, 2016 at 1:00 PM, Michael Jerris <mike@jerris.com> wrote:

The only way with our current sip module to accomplish either of these would be to put a sip proxy out front to handle that behavior, or to somehow use iptables to block the traffic

On Jun 1, 2016, at 3:40 PM, Oleg Stolyar <olegstolyar@gmail.com> wrote:

Hi,

In order to protect against scanning attacks I'd like for FS to not respond to INVITES unless they match certain conditions.  

I understand that currently FS always responds with 100 Trying right away before processing the call and then, if the call does not match anything in the dialplan, responds with a 302 Moved Temporarily.

The 302 can be replaced with another response code (for example 403 Forbidden which is what I am doing now) using the respond dialplan app.   However, that might encourage the scanner to keep trying.

So I guess there are two questions:

1. Is there a way not to send back 100 Trying at all?

2. Is there a way to not send any final response?