TCP/IP routing and switching.
LAN security: securing LAN devices, Network Admission Control technoligies.
WAN/Internet security: Firewalls, VPNs, IPS.
Voice over IP
Cisco Unified Communication based IP telephony.
Voice Gateways both in enterprise and SP environment.
CISCO, HP, Ruckus Wireless, Paloalto networks, Riverbed, Extreme network, Fortinet