Table of Contents
Advertisement
Chapter A Reference Tables
Quality of Service (QoS) Table
Quality of Service (QoS) Table
®
1-Port Channelized STS-1e, T1 Format Module User Guide, Issue 1
PacketStar
A-36
Table A-12 details the PSAX system support of defined ATM quality of service
(QoS) classes.
Table A-12. PSAX System-Supported Service Classes
ATM Service Class
Constant Bit Rate (CBR)
Variable Bit Rate—Real
Time (VBR-RT)
Variable Bit Rate—Non-
real Time (VBR-NRT)
Unspecified Bit Rate (UBR) This service operates on a connection basis and
Table A-13 illustrates the attributes of the classes of service supported by the
Multiservice Media Gateway system software.
Table A-13. Class of Service Descriptions
Constant Bit
Rate (CBR)
QoS Class
Class 1
Applications Voice and
video
Bit Rate
Constant
Description
This service operates on a connection basis and
offers consistent delay predictability. CBR is
used for applications such as circuit emulation,
voice, and video.
This service operates on a connection basis and
offers very low delay variance but requires
access to a variable amount of network band-
width. VBR-RT is used for such applications as
packet video and voice.
This service operates on both a connection and
connectionless basis and allows delay variance
between the delivery of cells. VBR-NRT is used
for data applications that have potentially
bursty traffic characteristics, including LAN
interconnections, CAD/CAM, and multimedia.
This class can be used to support switched
multimegabit data service (SMDS).
allows for raw cell or best-effort transport by
the network. In UBR service, cells are trans-
ported by the network whenever bandwidth is
available and traffic is presented by the user.
Data using UBR service is more apt to be dis-
carded during peak traffic times in deference to
data using other classes of service.
Variable Bit
Rate Real
Variable Bit
Time
Rate Non-real
(VBR-RT)
Time (VBR-NRT)
Class 2
Classes 3, 4
Packet
Data
video and
voice
Variable
Unspecified Bit
Rate (UBR)
Class 5
Release 7.0
255-700-184
Advertisement
Table of Contents
