NAT traversal: replacing rttproxy with external RTP IP address in FS
Hi all, TL;DR: Does anybody know of a way to convince FS to insert an external RTP IP into the SDP even if the signalling is coming from a client behind the same NAT? I'm currently using kamailio and rtpproxy behind a NAT in conjunction with FS, but I'd like to eliminate rtpproxy from the equation and get FS to handle all of the RTP NAT. I've set the ext-rtp-ip in the SIP profile and FS seems to have accepted it, but FS still sends out SDPs with the local IP address in them. I'm assuming that this is happening because the client that is forwarding the INVITE is behind the same NAT and therefore FS is not inserting the external IP address into the SDP, but I might be wrong. I'm using version 1.4.15-1. Currently I've got this topology for signalling: CLIENT <-> PUBLIC INTERNET <-> NAT <-> KAMAILIO <-> FS And this topology for media: CLIENT <-> PUBLIC INTERNET <-> NAT <-> RTPPROXY <-> FS whereby rttproxy advertises itself on a public IP and the external firewall has static port forwards set up for ephemeral RTP ports. FS is a B2BUA in this setup. I'd like to replace the media topology with this: CLIENT <-> PUBLIC INTERNET <-> NAT <-> FS and port forward RTP to the FS instance in the firewall. As a proof of concept hack, I was able to get end to end media going between two different clients, by rewriting the local IP of the FS instance in the outgoing SDP on the outbound leg in kamailio. But I'd like to be able to set the correct external IP as part of the normal SDP patching process in FS. Thanks, Ben
As far as i know fs does not change sdp when bypass media is set to true? Have you checked that? 06 февр. 2015 г. 6:54 пользователь "Ben Hood" <0x6e6562@gmail.com> написал:
Hi all,
TL;DR: Does anybody know of a way to convince FS to insert an external RTP IP into the SDP even if the signalling is coming from a client behind the same NAT?
I'm currently using kamailio and rtpproxy behind a NAT in conjunction with FS, but I'd like to eliminate rtpproxy from the equation and get FS to handle all of the RTP NAT.
I've set the ext-rtp-ip in the SIP profile and FS seems to have accepted it, but FS still sends out SDPs with the local IP address in them.
I'm assuming that this is happening because the client that is forwarding the INVITE is behind the same NAT and therefore FS is not inserting the external IP address into the SDP, but I might be wrong.
I'm using version 1.4.15-1.
Currently I've got this topology for signalling:
CLIENT <-> PUBLIC INTERNET <-> NAT <-> KAMAILIO <-> FS
And this topology for media:
CLIENT <-> PUBLIC INTERNET <-> NAT <-> RTPPROXY <-> FS
whereby rttproxy advertises itself on a public IP and the external firewall has static port forwards set up for ephemeral RTP ports.
FS is a B2BUA in this setup.
I'd like to replace the media topology with this:
CLIENT <-> PUBLIC INTERNET <-> NAT <-> FS
and port forward RTP to the FS instance in the firewall.
As a proof of concept hack, I was able to get end to end media going between two different clients, by rewriting the local IP of the FS instance in the outgoing SDP on the outbound leg in kamailio.
But I'd like to be able to set the correct external IP as part of the normal SDP patching process in FS.
Thanks,
Ben
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I hadn't considered media bypass mode, so I can look into that to see how it will fit in with what I am trying to do. Do you know if media bypass is compatible with a B2BUA scenario? On Sat, Feb 7, 2015 at 5:40 PM, Kamil Nigmatullin <kamil.nigmatullin@gmail.com> wrote:
As far as i know fs does not change sdp when bypass media is set to true? Have you checked that?
You mean b2bua in kamailio? how can they interfere? 09 февр. 2015 г. 18:07 пользователь "Ben Hood" <0x6e6562@gmail.com> написал:
I hadn't considered media bypass mode, so I can look into that to see how it will fit in with what I am trying to do.
Do you know if media bypass is compatible with a B2BUA scenario?
On Sat, Feb 7, 2015 at 5:40 PM, Kamil Nigmatullin <kamil.nigmatullin@gmail.com> wrote:
As far as i know fs does not change sdp when bypass media is set to true? Have you checked that?
_________________________________________________________________________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
Official FreeSWITCH Sites http://www.freeswitch.org http://confluence.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
In my scenario, FS is the B2BUA - I wasn't aware that Kamailio could actually a B2BUA, I assumed it was only a SIP proxy. In any case, I was thinking that FS would terminate the media streams of both the A-leg and the B-leg. Because of this, I was wondering how media bypassing would work, since FS would have to mux the media from both legs. Or maybe my understanding of FS is not good enough?
On 9 Feb 2015, at 17:06, Kamil Nigmatullin <kamil.nigmatullin@gmail.com> wrote:
You mean b2bua in kamailio? how can they interfere?
09 февр. 2015 г. 18:07 пользователь "Ben Hood" <0x6e6562@gmail.com> написал:
I hadn't considered media bypass mode, so I can look into that to see how it will fit in with what I am trying to do.
Do you know if media bypass is compatible with a B2BUA scenario?
On Sat, Feb 7, 2015 at 5:40 PM, Kamil Nigmatullin <kamil.nigmatullin@gmail.com> wrote:
As far as i know fs does not change sdp when bypass media is set to true? Have you checked that?
_________________________________________________________________________ Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
Official FreeSWITCH Sites http://www.freeswitch.org http://confluence.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
Professional FreeSWITCH Consulting Services: consulting@freeswitch.org http://www.freeswitchsolutions.com
Official FreeSWITCH Sites http://www.freeswitch.org http://confluence.freeswitch.org http://www.cluecon.com
FreeSWITCH-users mailing list FreeSWITCH-users@lists.freeswitch.org http://lists.freeswitch.org/mailman/listinfo/freeswitch-users UNSUBSCRIBE:http://lists.freeswitch.org/mailman/options/freeswitch-users http://www.freeswitch.org
participants (2)
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Ben Hood
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Kamil Nigmatullin