Datasheet

Cisco Systems, Inc.
All contents are Copyright © 1992–2003 Cisco Systems, Inc. All rights reserved. Important Notices and Privacy Statement.
Page 4 of 8
Table 3 ATM Service Category Attributes and Guarantees
Available Bit Rate (ABR)
Used to maximize bandwidth utilization of the ATM link through the use of
congestion feedback notification (resource management cells). Both PCR and MCR
specify the ABR connection. The transmit rate of each connection is flow-controlled
such that the rate will always be between the user specified values for a minimum
and peak rate.
Constant Bit Rate (CBR)
Intended for real-time applications such as SNA traffic, voice, and video, which
require a fixed bandwidth and low cell delay. CBR in initial release supports data
only.
Service
Category Traffic Description
Minimum Loss
Cell Loss Ratio
(CLR)
Delay
Variance Bandwidth
Use of
Feedback
Control
UBR
PCR No No No No
UBR+
PCR X No No No
rt-VBR
PCR, SCR, MBS X X X No
nrt-VBR
PCR, SCR, MBS X No X No
ABR
PCR, MCR+, behavior
parameters
XNoXX
CBR
PCR X X X No
ATM Service Categories Typical Use