255-700-025
E-3
PacketStar
™
Access Concentrator 60 User Guide
, Issue 1
Release 6.3.0
Appendix E Reference Information
QoS Information Tables
system. The flexibility of the Access Concentrator systems allows the user to
tailor the system based on the required service applications and the selection
of the appropriate priority levels.
Table E-3. Cell-Loss and Cell-Delay Characteristics of AT M Service Classes
ATM Classes of
Service
QoS Class Sup-
ported by AC
Systems
Cell Loss
Tolerance
Cell Delay
Tolerance
Internal
Priority
Constant Bit
Rate (CBR)
Class 1
High
Very Low
CBR-1
Class 1
High
Very Low
CBR-2
Class 1
High
Low
CBR-3
Class 1
High
Low
CBR-4
Variable Bit
Rate (VBR)
Variable Bit
Rate, Real Time
(VBR-RT)
Class 2
Very Low
Very Low
VBR-1
Class 2
Low
Low
VBR-2
Class 2
Low
Low
VBR-3
Variable Bit
Rate, Nonreal
Time
(VBR-NRT)
Classes 3, 4
Low
Medium
VBR-4
Classes 3, 4
Low
High
VBR-5
Unspecified Bit
Rate (UBR)
Class 5
Very High
Very High
VBR-6
Table E-4. Mapping AT M Service Classes to Access Concentrator Systems
Priority Levels
ATM Classes of
Service
Internal
Priority
PVC Connection
Configuration
Selections
Service Examples
Constant Bit
Rate (CBR)
CBR-1
CBR1
911 calls
CBR-2
CBR2
Preferred customers
CBR-3
CBR3
Standard
CBR-4
CBR4
Cellular
Variable Bit Rate
(VBR)
VBR-1
VBR-express
Network
management
Variable Bit Rate
Real Time
(VBR-RT)
VBR-2
VBR-RT1
Real-time videos
VBR-3
VBR-RT2
MPEG1-2/JPEG
Variable Bit Rate
Nonreal Time
(VBR-NRT)
VBR-4
VBR-NRT1
FR data
VBR-5
VBR-NRT2
FTP/e-mail transfer
Unspecified Bit
Rate (UBR)
VBR-6
UBR
IP data