[Serusers] SEMS & mediaproxy

[Ezequiel Colombo]

Thanks Jan, i am trying without use_media_proxy() but when SEMS answer the
call, try to send RTP of greeting to the ip/port of the received SDP invite
message. If i dont use media_proxy the c= line of the SDP received by sems
is a private ip address. For this reason SEMS receive an icmp error message,
cannot reach the private address.

Also if the caller is a Cisco gateway with a public IP address, sems start
sending the RTP of greeting to the public ip/port of the gateway, but
receive an icmp port unrecheable message. (the Cisco gateway dont send
a=direction in your SDP body).

You explain about the SDP a=direction:active. This must be set in the SDP of
the INVITE or in the SDP of the 200OK sent back by sems ?
If i am using mediaproxy and not nathelper, can i set the a=direction:active
in the SDP contents ???

Thanks again for your help.

----- Original Message -----
From: "Jan Janak" <jan at iptel.org>
To: "Ezequiel Colombo" <ecolombo at arcotel.net>
Cc: <serusers at lists.iptel.org>
Sent: Friday, May 28, 2004 11:33 AM
Subject: Re: [Serusers] SEMS & mediaproxy


> First of all, there is no need to use rtpproxy when one side of the
> dialog is SEMS in the public internet (which, I believe, is the case
> here). SEMS implements the symmetric RTP extensions, all you have to do
> is make sure that there is a=direction:active flag in the SDP when the
> callee is behind NAT. You do not have to rewrite IPs at all, because in
> this case SEMS will wait for the first RTP packet and send RTP packets
> there instead of the IP from SDP.
>
> That means, do not call use_media_proxy when forwarding to SEMS. Make
> sure that SDP contains the flag mentioned above when forwarding to SEMS.
>
>   Jan.
>
> On 26-05 10:27, Ezequiel Colombo wrote:
> > I have problems with sems and SER+mediaproxy
> > When i send a call to sems for voicemail the SDP content received by
sems have the c= line with the private address of caller. Before send the
call to sems my SER use mediaproxy to fix nat problems, but sems dont
receive the SDP changed and the RTP generated by SEMS is sent to the wrong
ip address.
> >
> > -- on my ser.cfg --
> >         if (method=="INVITE") {
> >            log(1,"ROUTE_0: INVITE METHOD\n");
> >
> >            if (!search("^Record-Route:")) {
> >               log(1,"ROUTE_0: Use Mediaproxy");
> >               use_media_proxy();
> >            };
> > ...
> >         log(1,"ROUTE_1: ARCOTEL-TO-ARCOTEL ");
> >         lookup("aliases");
> >         if (!lookup("location")) {
> >            log(1, "ROUTE_1: USER OFFLINE OR INVALID\n");
> >            route(8);
> >            break;
> >         };
> > ...
> > route[8] {
> >        log(1,"ROUTE_8: VOICEMAIL");
> >         if (!t_newtran()) { sl_reply_error(); break; };
> >         use_media_proxy();
> >         t_reply("183","Conectandose");
> >
> >         if(!vm("/tmp/am_fifo","voicemail")){
> >            log(1,"could not contact voicemail\n");
> >            t_reply("500","could not contact voicemail");
> >         };
> > break;
> > }
> >
> > -- on my ser.cfg --
> >
> > -- on syslog file --
> > May 26 10:13:17 billing /usr/sbin/ser[9814]: ROUTE_1: ARCOTEL-TO-ARCOTEL
> > May 26 10:13:17 billing /usr/sbin/ser[9814]: ROUTE_1: USER OFFLINE OR
INVALID
> > May 26 10:13:17 billing /usr/sbin/ser[9814]: ROUTE_8: VOICEMAIL
> > May 26 10:13:17 billing proxydispatcher[9919]: command request
3B48F4D2-CB2B-42B2-80AD-F5064BC02868 at 10.10.0.29 10.10.0.29:800
> > 0 200.80.35.6 arcotel.net local arcotel.net local
X-Lite=20release=201103a flags=
> > May 26 10:13:17 billing proxydispatcher[9919]: domain arcotel.net
doesn't define any mediaproxy.
> > May 26 10:13:17 billing proxydispatcher[9919]: will use default
mediaproxy for this call.
> > May 26 10:13:17 billing mediaproxy[25721]: command request
3B48F4D2-CB2B-42B2-80AD-F5064BC02868 at 10.10.0.29 10.10.0.29:8000 20
> > 0.80.35.6 arcotel.net local arcotel.net local X-Lite=20release=201103a
flags=
> > May 26 10:13:17 billing proxydispatcher[9919]: forwarding to mediaproxy
on /var/run/mediaproxy.sock: got: 'public.ip.proxy 35062
> > May 26 10:13:17 billing /usr/sbin/ser[9812]: ROUTE_0: Fixing Contact
> > May 26 10:13:17 billing /usr/sbin/ser[9812]: ACK
> > May 26 10:13:17 billing /usr/sbin/ser[9812]: END ROUTE_0 - RELAY
> > May 26 10:13:27 billing /usr/sbin/ser[9839]: ROUTE_0: Fixing Contact
> > May 26 10:13:27 billing /usr/sbin/ser[9839]: BYE
> > -- on syslog file --
> >
> > -- on SEMS trace --
> > ...
> > (9780) DEBUG: execute (AmServer.cpp:277): body: `v=0
> > o=ecolombo 2205701 2205771 IN IP4 10.10.0.29
> > s=X-Lite
> > c=IN IP4 10.10.0.29
> > t=0 0
> > m=audio 8000 RTP/AVP 3 0 101
> > a=rtpmap:0 pcmu/8000
> > a=rtpmap:3 gsm/8000
> > a=rtpmap:101 telephone-event/8000
> > a=fmtp:101 0-15
> > ...
> > (9920) DEBUG: setRAddr (AmRtpStream.cpp:333): RTP remote address set to
10.10.0.29:8000
> > (9920) DEBUG: negotiate (AmSession.cpp:150): Sending Rtp data to
10.10.0.29/8000
> > ...
> > -- on SEMS trace --
> >
> > Thanks
> > Ezequiel Colombo
>
> > _______________________________________________
> > Serusers mailing list
> > serusers at lists.iptel.org
> > http://lists.iptel.org/mailman/listinfo/serusers
>
>