Appendix A
Acronyms
type of service
TOS
Token Ring Bridge Relay Function
TrBRF
Token Ring Concentrator Relay Function
TrCRF
token rotation timer
TRT
time to live
TTL
teletype
TTY
U
universal asynchronous receiver/transmitter
UART
unspecified bit rate
UBR
Unidirectional Link Detection Protocol
UDLD
User Datagram Protocol
UDP
User-Network Interface
UNI
Coordinated Universal Time
UTC
V
Variable Bit Rate
VBR
Virtual Circuit
VC
Virtual Channel Connection
VCC
Virtual Channel Descriptor
VCD
Virtual Circuit Identifier
VCI
Virtual Configuration Register
VCR
Virtual LAN
VLAN
VLAN Membership Policy Server
VMPS
Virtual Path Identifier
VPI
78-12647-02
Software Configuration Guide—Catalyst 4000 Family, Catalyst 2948G, Catalyst 2980G, Releases 6.3 and 6.4
A-9