I work at Dell.
The Lync settings I've tried to login on my iPhone are:
Username: user@dell.com
Pass: pass
Domain\Username: Asia-Pacific\user , Americas\user (etc)
Auto-Detect Server: ON
I read somewhere about federation.dell.com but never figured out the correct setrtings.
Error message I see: Can't sign in. Please check your account information and try again.
Any Ideas?