I would provide the advanced support remotely regarding Firewall, Endpoint Protection and Wireless products solution.
Firewall : Sophos, PaloAlto, Barracuda, Fortinet and Sangfor.
Endpoint Protection (Antivirus) : Sophos and Bitdefender.
Wireless product : Cisco, D link, Aruba, Ubiquiti and Ruckus (We provide AP and controller configuration).
Windows Servers (2003, 2008, 2008 R2, 2012, 2012 R2)
Server Virtualization (Hyper-V, VMware, XenServer)