I have extensive experience and expert knowledge in the following skills areas:

Systems Administration
file server admin
mail server admin
DNS admin (BIND 9 and 10)

Networking
routers: from simple SOHO routers to complex Cisco IOS installs.
security: firewalls, network intrusion detection
connectivity: fiber optic, T-1/T-3, frame relay, cable, ISDN (BRI and PRI), xDSL, WiFi, mobile data

Telephony
PBX/key system admin: Nortel, Lucent
VoIP admin: location and vendor hosted

Desktop Operating Systems
Windows: through Windows 10
Mac OS: through 10.13.x
Linux: OpenSUSE, Linux Mint, Ubuntu

Mobile Operating Systems
iOS: through 11.2.x
Android: through 8.1.x (Oreo)