Cisco Systems 8600 Series Speech detection, Split clock, Status Enquiry, StrataBus, Subrate data

speech detection

Determining the presence or absence of speech for Digital Speech Interpolation. Performed in either the CDP card or VDP card in an IPX node.

split clock

A data clocking configuration where the timing for the transmit data is obtained from one source (e.g. user device) and the timing for the receive data is obtained from another source (e.g. IPX switch).

Status Enquiry

A message transmitted by a FR NNI port requesting an updated status from the attached foreign network. This message is used as a heartbeat to detect when a port has failed.

StrataBus

On the BPX switch, contains crosspoint wiring used to carry ATM trunk data between both the network interface and service interface modules and the crosspoint switch as well as providing control, clock, and communications.

subrate data

Multiple low-speed data circuits carried in a single DS0 timeslot.

superrate data

Single high-speed data circuit carried in multiple DS0 timeslots.

SCR (Sustained Cell Rate)

Long term limit on the rate a connection can sustain.

SVC (switched virtual circuit)

A virtual circuit that is dynamically established on demand and torn down when transmission is complete. SVS do not need to reserve any network resources when they are not in use. Called a switched virtual connection in ATM terminology. Compare with PVC.

system bus

A two-part IPX data bus. One part carries system commands between the PCC all other IPX cards; the other carries time division multiplexed data.

T

T1

The standard US. multiplexed 24-channel voice/data digital span line. Operates at a data rate of 1.544 Mbps.

T3

Transmission service at DS3 rate of 44.736 Mbps.

TBE (Transient Buffer Exposure)

The negotiated number of cells that the network would prefer to limit the source to send during the start-up period.

TDM (time division multiplexing)

The process of combining several communication channels by dividing a channel into time increments and assigning each channel to a timeslot.

Glossary E-17