[RTPproxy Devel] Automatic bridging for RTP proxy and advertised address for external NAT

[Emmanuel BUU]

Hello everybody,

I would like to submit two enhancement proposal for the RTPproxy software:

1/ automatic bridging handling

RTP proxy can be run in bridged mode. With the -l IP1/IP2 option, one 
can mediate between two unrelated networks (e.g. a private network and 
the public Internet) by running the rtpproxy software on a host with two 
nework interface with each of it connected to the neworks. It is the SIP 
proxy that needs to deterline wether the packet is coming from the 
internal network or the
external network and pass it on to the RTP proxy through the protocol.

I propose that this determination is done inside the rtpproxy software. 
The idea would be describe the internal nework (IP / mask, bind 
address). When a create or update command would
arrive, ithe the IP and port to be contacted present in the comand frame 
would be compared against the internal nework definition. Therefor, RTP 
proxy create the socket on the right bind address
and provide it in the asnwer. If the IP provided in the commande does 
not match the internal network definition, it is considered to be on the 
external network.

2/ External nat handling

I would also to handle the case where RTP proxy is behind a NAT (one to 
one NAT). If the communication is on the internal network then the 
previous processing is applied
if the communication is to be done with the external network, rtp proxy 
would bind to the same interface but advertise the NATed adress in the 
asnwer.

We propose to implement these two enhancements and this lead me to 
another question. RTPProxy has currently no configuration file. Would 
the crowd here consider an addition ?

Emmanuel BUU
IVeS
http://www.ives.fr/