I have Lync 2010 infrastructure but does not have an Edge server in the dmz. I have asked to federate with another company. We do have Site-to-Site VPN with company and they use Office 360 with masqueraded domains.

Questions:

Do I need to have Edge server in the DMZ or internal even for Site-to-Site VPN?

How can federation on Site-to-Site VPN be configured? Any security risk? Is Federation with office 360 different from another partner Edge server?

Any good blog article on the configurations?

• Edited by Kojo Obeng Antwi 17 hours 15 minutes ago

Yes, sorry, you'd need an Edge server to talk to another SIP domain, Office 365 or on premise.

Open federation with Office365 is the pretty much the same. 

• Edited by Anthony Caragol 15 hours 41 minutes ago
• Proposed as answer by Kent-HuangModerator 2 hours 34 minutes ago

https://itacademy.microsoftelearning.com/default.aspx?registered=0

Hi,

You have to deploy Edge Server in DMZ to federate with other Lync Server on premise or Office 365.