Assured Forwarding Classes And Three-Level; Assured Forwarding Classes And Two-Level Drop Precedence; Mapping Phbs To Qos Profiles - Extreme Networks BlackDiamond 6800 Installation And User Manual

Table 3-10: Assured Forwarding Classes and Three-Level Drop Precedence
Drop-Precedence Level
Low drop precedence
Medium drop precedence (AF12) 001100
High drop precedence
Table 3-11: Assured Forwarding Classes and Two-Level Drop Precedence
Drop-Precedence Level
Low drop precedence
High drop precedence
In addition, a network element that complies with the DiffServ standards must also
provide a recommended default code point, which must be unique for code points in the
standard space. The default PHB describes the common, best-effort forwarding behavior
offered by existing network elements, as defined in RFC 1812.
As an additional differentiation, a set of code points has been allocated for use as the
Class Selector code points, which describe the minimum forwarding handling
requirements needed to preserve compatibility with existing practices while respecting
flexibility for the future.
Table 3-12 and the command examples that follow show how the standard per-hop
behaviors (PHBs) might be mapped onto ExtremeWare QoS profiles qp1 through qp8.
Table 3-12: Mapping PHBs to QoS Profiles
PHB
QoS
Profile
DSCP
Asynchronous Transfer Mode (ATM) Module Installation and User Guide
AF1
(AF11) 001010
(AF13) 001110
AF1
(AF11) 001010
(AF12) 001100
(AF13) 001110
Default Class Selector
qp1 qp2 qp3
000000 001000 110000
010000 111000
011000
100000
101000
AF2
(AF21) 010010 (AF31) 011010
(AF22) 010100 (AF32) 011100
(AF23) 010110 (AF33) 011110
AF2
(AF21) 010010 (AF31) 011010
(AF22) 010100 (AF32) 011100
(AF23) 010110 (AF33) 011110
AF1 AF2
qp4 qp5
001010 010010 011010
001100 010100 011100
001110 010110 011110
Configuring QoS Functions
AF3 AF4
(AF41) 100010
(AF42) 100100
(AF43) 100110
AF3 AF4
(AF41) 100010
(AF42) 100100
(AF43) 100110
AF3 AF4 EF
qp6 qp7 qp8
100010 101110
100100
100110
3-41