Hi,

We have a domain which is worldly registered and by using this domain we want to use Microsoft Lync facilities (it is notable

to mention that we use Microsoft Lync 2010). By now we established our internal communication nevertheless when we

were trying to use its external properties we couldnt make it happen, if it is possible in order to solve our problem tell me

what should I do step by step.

Hi,

You can follow my bog to deploy and configure Edge server for Lync 2010

http://thamaraw.com/category/lync-server-architecture-2010/lync-server-2010-edge-server/

Agree with Thamara, I suspect you need an edge server.

Not sure 'suspect' is the right word there Anthony :) 100% you need a edge server

Sorry, I meant I suspect he doesn't have one.  :)  But yeah, 100% if he doesn't. 

Before you deploy Lync Edge, you can refer to the planning for external user access at

http://technet.microsoft.com/en-us/library/gg399048(v=ocs.14).aspx

For the deployment of Lync Edge Server, you can check the Microsoft official document at

http://technet.microsoft.com/en-us/library/gg398918(v=ocs.14).aspx