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

Configuring the PoS Module
Table 3-9: Assured Forwarding Classes and Three-Level Drop Precedence
Drop-Precedence Level
Low drop precedence
Medium drop precedence (AF12) 001100
High drop precedence
Table 3-10: 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 3-11 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 3-11: Mapping PHBs to QoS Profiles
PHB Default Class Selector
QoS qp1 qp2
Profile
DSCP 000000 001000
010000
011000
100000
101000
3-56
AF1 AF2
(AF11) 001010 (AF21) 010010
(AF22) 010100
(AF13) 001110 (AF23) 010110
AF1 AF2
(AF11) 001010 (AF21) 010010
(AF12) 001100 (AF22) 010100
(AF13) 001110 (AF23) 010110
AF1
qp3 qp4
110000 001010
111000 001100
001110
AF3
(AF31) 011010
(AF32) 011100
(AF33) 011110
AF3
(AF31) 011010
(AF32) 011100
(AF33) 011110
AF2 AF3
qp5 qp6
010010 011010 100010
010100 011100 100100
010110 011110 100110
Packet Over SONET Module Installation and User Guide
AF4
(AF41) 100010
(AF42) 100100
(AF43) 100110
AF4
(AF41) 100010
(AF42) 100100
(AF43) 100110
AF4 EF
qp7 qp8
101110