[Asterisk-Users] Open Ports

[Norman Zhang]

>>May I ask what ports are necessary for SIP communication through a
>>firewall? I read somewhere that UDP/5060 alone is enough. Some
>>recommends more ports to be opened for RTP.
> 
> Both the above statements are correct.
> 
> SIP uses port 5060
> 
> RTP uses multiple ports, typically in the range 10000-20000
> 
> Remember that SIP and RTP are different - SIP is used to set up the call; RTP 
> is used to carry the audio once the call has been set up.

Thanks. May I ask what security control can be applied to RTP besides 
reducing the opened range? Are there stateful inspection can be done on 
this?

Regards,
Norman Zhang