Your company has a Skype for Business Server 2015 infrastructure that contains two topology sites
named London and Seattle. Each site contains an Enterprise Edition Front End pool and an Edge Server.
The external DNS records are configured as shown in the following table:

All users use the Skype for Business client. Some of the users use the Skype for Business client from non-
domain joined computers.
You need to ensure that the users in the London site use the Edge Server in the London for authentication
and the users in the Seattle site use the Edge Server in the Seattle site for authentication. The solution
must minimize administrative effort.
What should you do?