Cisco Systems 8600 Series manual Timestamp, Trm, Trunk conditioning, Trunk queues

timestamp

A field in certain FastPacket formats that indicates the amount of time the packet has spent waiting in queues during the transmission between its source and destination nodes. Used to control the delay experienced by the packet.

Trm

An upper bound on the time between RM cells for an active source, i.e., RM cell must be sent at least once every Trm msec.

trunk

A physical link between two nodes. The trunk may be one that supports 24-byte FastPackets (packet trunk), or one that supports 53 byte ATM cells (cell trunk.)

trunk conditioning

A set of signalling and information bits that indicate a DS1 line failure.

trunk queues

The buffers in packet line cards (NTC, TXR) where the various FastPackets are queued up for transmission over the packet line(s). The buffers attempt to prioritize each packet so it experiences minimum delay.

U

-law

An analog to digital encoding scheme used to convert voice samples to an 8-bit data word used in D3/D4 T1 multiplex equipment.

UBR

Unspecified Bit Rate.

UNI (User to Network Interface)

The user to network interface, used for ATM connection to CPE. Compare with NNI.

UPC (Usage Parameter Control)

A general procedure for controlling the rate of user data applied to an ATM network. There are a number of different algorithms for performing UPC. See also GCRA.

USART (Universal Synchronous/Asynchronous Receiver Transmitter)

A single-chip device used in certain applications that allows microprocessors to communicate with input/output (I/O) devices.

User to Network Interface (UNI)

The protocol at a frame relay port that passes information between the network and the user device attached to the port.

V

V.21

A CCITT interface standard often used for data transmission over modems.

E-18Cisco BPX 8600 Series Reference