Index_U

U

UART (Universal Asynchronous Receiver-Transmitter), 320

UDP (User Datagram Protocol), 84, 119, 169, 555

UL listing for surge protectors, 414

unicast packets, 170

Uniform Resource Locators (URLs), 554

uninterruptible power supplies (UPSs), 260, 262, 417–418, 554

unique passwords, 363–364

Universal Asynchronous Receiver-Transmitter (UART), 320

Universal Serial Bus (USB), 320

Unix application support subsystem in Windows NT, 229

Unix operating system, 234–235, 554

client for, 353–354

firewalls for, 373–374

Linux, 235–236

SCO Unix, 236

Solaris, 236–237

UnixWare, 222, 236

unknown protocol packets, 170

unshielded cable. See UTP (unshielded twisted-pair) cable and installations

updating virus protection, 437–439

upgrades, 555

uploading files, 184–185

UPSs (uninterruptible power supplies), 260, 262, 417–418, 554

uptime, 555

urgent pointer field, 112

URLs (Uniform Resource Locators), 554

USB (Universal Serial Bus), 320

Use DHCP for WINS Resolution option, 148

user accounts. See accounts

User Datagram Protocol (UDP), 84, 119, 169, 555

user interfaces

for Novell NetWare, 209–210, 210

for Windows NT, 224

user-level security, 356, 555

User Manager for Domains, 232, 232, 483

user mode in Windows NT, 227–228

usernames

in client/server networks, 10

in FTP, 182

for logins, 458–459

utility NLMs, 215–216

UTP (unshielded twisted-pair) cable and installations, 26, 266, 267, 555

bridges in, 269–270

brouters in, 271

connecting, 27–28

hubs in, 268–269

patch panels in, 267–268

repeaters in, 268

routers in, 270

in Token Ring standard, 69