Hi all,

I have a question about Control RTPProxy in Bridge mode with distributed Kamalio topology, including a SIP Load Balance, RTPProxies and some SIP Proxies behind. SIPProxies control RTPProxy by Route [NATMANAGE].

                                                                                PUBLIC IP ---- Load Balance -----> SIP Proxies

                                                                                                                                                     |        

                                                                                                                                                     | control socket      

PUBLIC IP < ----- RTPProxy <-----------------|

In the standalone Kamailio solution (only one SIP Server – without Load Balance), I configured RTPProxy bridge mode, works PERFECTLY!!! , BUT in the distributed Kamailio solution (LoadBalance –> Proxies) has big issue with RTP: 

- UA in front of NAT has only upload direction (1 way RTP) but UA behind NAT has both direction (2 ways RTP).  

RTP stream from UAC ------ > NAT ------ > RTPProxy Public Interface ------ > RTPProxy Local Interface -------> UAS in local area network

RTP stream from UAS in local area network ------ > RTPProxy Local Interface -------> STOPs HERE!!!, NOT Transfers out

The RTPProxy control is performed on the SIP Proxy (Route NATMANAGE has many cases with flags WFROCEE, WFROCEI, WFROCIE).

In the case the same UA in front of NAT call (RTPProxy mode “WEE”), the call occurs normally, RTP Streams is OK on both sides, but the call in cases EI and IE has problems above.

What could be going on?

Thanks,

Nguyen Anh Tuan