[Asterisk-Users] Narrowing RTP port range

[Rich Adamson]

> I'm trying to lock down my asterisk install as much as possible and I
> keep reading about people saying 'you can narrow the range of ports in
> rtp.con' (by default it's from 10000 to 20000 I think).
> 
> My question is this - how much can I narrow it down?  Can I narrow it to
> 10 ports, or can the ports not be reused for additional conversations?
> 
> I guess what I'm asking is - does the number of ports in the range have
> anything to do with the number of simultaneous connections or anything
> like that?

Yes, you can narrow it down. One port will be required for each
leg of a call. So if sip/123 called sip/345, that's two ports. I'd
suspect that some ports are used for other purposes besides just a
conversation, so adding more is certainly more in your best interest
then cutting them short.