ATM Connections 7-13
ATM Connection Configuration
CBR Connections
The CBR (constant bit rate) category is a fixed bandwidth class. CBR traffic is more time
dependent, less tolerant of delay, and generally more deterministic in bandwidth requirements. CBR
is used by connections that require a specific amount of bandwidth to be available continuously
throughout the duration of a connection. Voice, circuit emulation, and high-resolution video are
typical examples of traffic utilizing this type of connection. A CBR connection is allowed to
transmit cells at the peak rate, below the peak rate, or not at all. CBR is characterized by peak cell
rate (PCR).
The parameters for a CBR connection are shown in Figure 7-3 in the sequence in which they occur
during the execution of the addcon command. The CBR policing definitions are summarized in
Table 7-5.
Figure 7-3 CBR Connection Prompt Sequence
Table 7-5 CBR Policing Definitions
Connection Type
ATM Forum TM
spec. 4.0
conformance
definition
PCR Flow
(1st leaky
bucket)
CLP
tagging (for
PCR flow)
SCR Flow
(2nd leaky
bucket)
CLP
tagging (for
SCR flow)
CBR
CBR.1
when policing set to
4 (PCR Policing
only)
CLP(0+1)
no off n/a
CBR When policing set
to 5 (off)
off n/a off n/a
CBR
PCR(0+1)
%Util
CDVT(0+1)
Policing (4 or 5)
For policing prompt:
4 = PCR policing only
5 = policing off
Note: BW allocation = (PCR)x(%Util)
10224
1
1
Trunk cell routing
restrict (Y/N) [Y]
