hi There, in my environment, none of the users are able to share their desktop with remote domain users. call fails as soon as they make any sharing. looking at the Lync diagonostic report I see the below error. Any idea what must be wrong in my environment, as i'm clueless to move further on this issue?

Note: This issue does not occure when they are in the local LAN, but it hapens when they use internet or wifi network. Is it something i need to validate from network aspect? 

Below the Diagnostic header from monitoring server:

• Edited by Magudeeswaran M Saturday, October 25, 2014 12:49 PM

The problem is network connectivity 

Please refer to 

http://dusk1911.wordpress.com/2011/11/28/lync-audiovideo-not-working/

and also 

http://www.ucprimer.com/tech-blog/ms-client-diagnostics-23-reasoncall-failed-to-establish-due-to-a-media-connectivity-failure-when-one-endpoint-is-internal-and-the-other-is-remotecalleemediadebugaudioicewarn0x80012b

assuming Lync to Lync Im works fine 

Hi,

It should be network issue.

You need to double check ports for Edge External.

For Edge External interface:

Make sure the following ports open: SIP/MTLS/5061 (in/out), SIP/MTLS/5061 (in/out), RTP/TCP/50K range (out)

More details:

http://technet.microsoft.com/en-us/library/gg425891(v=ocs.14).aspx

Best Regards,

Eason Huang

Please, Check firewall ports.

http://technet.microsoft.com/en-us/library/gg425891(OCS.14).aspx

443: Client to server SIP traffic for remote user access

5061: Federation and connectivity with a hosted Exchange service

50,000-59,999: Media exchange, Application sharing/desktop sharing and File transfer

yes Lync to Lync IM works fine.

my problem is quite confusing really...

Application sharing does not work with one specific federated domain only over internet , but the same works on the LAN. my trouble here is, the same application sharing  does work well with any other federated domain over the same internet connection. because of the above reason i'm unable to confirm its a network or port related issue. any idea how can i segregate the issue now?

my problem is quite confusing really...

Application sharing does not work with one specific federated domain only over internet , but the same works on the LAN. my trouble here is, the same application sharing  does work well with any other federated domain over the same internet connection. because of the above reason i'm unable to confirm its a network or port related issue. any idea how can i segregate the issue now?

Are you remote clients able to have audio video call with your internal user 

I would suggest from an external network test your setup and your federated setup if you have test account 

using https://testconnectivity.microsoft.com/ audio test options

this issue was fixed after we fine tune our firewall settings, here is what we did.

Basically Lync is using an anonymous Cipher (TLS_DH_anon_WITH_RC4_128_MD5) for TCP traffic, this was previously not allowed in our firewall so the connections were dropped by firewall, hence we had to enable this in fireall in order to resolve this issue. you may either enable TCP or UDP for this chipher, but UDP is the most preferable option.

• Marked as answer by Magudeeswaran M Wednesday, August 19, 2015 1:56 AM