Remote party can view my presentation only after he shared her presentation first

[MA_Joulak]

we have both licenced dual screen, and we can see our video without problem.
When I shared my presentation the remote party can't see my presentation but his second screen become black. but if he shared his presentation I can shared mine and he can see that is his screan.
In the both case i dont have problem in my screens so i can see my/his presentation in my second screen.
What can i change in my configuration to correct this situation.
I have SX20 and remote party have tandberg.

You can see my video configuration in attached file

[Patrick Sparkman]

Quick glance at your configuration, it looks fine.  The only thing I would change is "Output HDMI 2 MonitorRole: Auto" to "Second", since you have the first output manually set.

It sounds as if something on their end might be misconfigured, especially when you say that you can see both yours and their presentation without issue.  One thing they could do is if they have another endpoint locally they can perform a test call within their network and try to share content, it could help determine if it's specifically their endpoint or something between you and them.

Are these endpoints registered to a VCS, CUCM, or standalone?  Any firewall between the two?

Is it possible to get a xConfiguration of their endpoint, and what model do they have, and what software version are you both running?

[MA_Joulak]

Thank you for your quick response
I haven't another endpoint locally and my SX20 work on standalone. it have a public adress and it's published in DMZ with NAT configuration.
Remote party have configuration with VCS... he have many endpoint and do many conference with other companys so if there is a problem it seem to be in my configuration.
When we try with other endpoint in dual or simple screen, we have always the same problem. he must share presentation first to do my presentation after.
Current software version is TCNC7.1.1.168aadf
in atteched file you can found xconfiguration witout my real ip.

[Martin Koch]

This sounds like a network issue to me.

NAT is always a chalange. It could  be that there is a ALG or NAT helper which is messing something up or something like that the needed ports are not properly NATed into the endpoint.

In general you need a N:N mapping of the required ports.

It can be that the port for the dual video is not open, the sharing from the remote site opens it and after you start the presentation it uses the opened ports.

You could try to place the remote endpoint temporary on a open public ip (though I always recommend having the management ports filtered out or at least use the latest software and secure passwords) just to verify if the problem still exists in this scenario.

I did not see that the call protocol type was mentioned, on a non registered endpoint I would recommend to use h323.

Also be aware that with the software version you run (7.3.4 is the latest btw) it will not support encryption, but this might be a requirement if the endpoint is in a country with encryption restrictions.

[MA_Joulak]

hy martin and thanks for your answer.
Yes we work in H323 protocol and i published sx20 behind my firewall so i have a N:N mapping of dynamic ports start form 1024 to 65535 in tcp and udp.
the remote endpoind is not in our company so we can't do any change in his configuration or his architecture. I can only make change in my endpoint.

In sx20 i activate H323 and specified the public address of sx20.

remote endpoint didn't have ACL on my public ip.

the ACL in my firewall permit all dynamic port in tcp/udp (1024-65535) for specified ip address of remote party in inbound and permit all dynamic port tcp/udp for my ip endpoind to all in outbound.

my ASA version 9.0(3)