beautypg.com

10 mapping to ietf diffserv classes – Planet Technology Planet Intelligent Gigabit Ethernet Stackable/Routing Switch WGSW-2402A User Manual

Page 164

background image

- 156 -

5.15.1.10 Mapping to IETF Diffserv Classes

The mapping between priority classes discussed in this chapter and elsewhere is shown below.

T

ABLE

5-6

M

APPING

B

ETWEEN THE

S

WITCH AND

IETF D

IFFSERV

C

LASSES

Gigabit

Port P7 P6 P5 P4 P3 P2 P1 P0

Megabit

Port P3

P2

P1

P0

IETF

NM EF AF0 AF1 AF2 AF3 BE0 BE1

As the table illustrates, P7 is used solely for network management (NM) frames. P6 is used for

expedited forwarding service (EF). Classes P2 through P5 correspond to an assured forwarding (AF)

group of size 4.

Finally, P0 and P1 are two best effort (BE) classes.

For 10/100 Mbps ports, the classes are merged in pairs—one class corresponding to NM+EF, two AF

classes, and a single BE class.

Features of the Switch that correspond to the requirements of their associated IETF classes are

summarized as the following.

Network management (NM)

and Expedited forwarding

(EF)

Global buffer reservation for NM and EF

Shaper for EF traffic on 1 Gbps ports

Option of strict priority scheduling

No dropping if admission controlled

Assured forwarding (AF)

Four AF classes for 1 Gbps ports

Configurable bandwidth partition, with option of WFQ

service.

Option of delay-bounded service keeps delay under

fixed levels even if not admission-controlled.

Random early discard, with configurable levels

Global buffer reservation for each AF class

Best effort (BE)

Two BE classes for 1 Gbps ports

Service only when other queues are idle means that

QoS not adversely affected

Random early discard, with programmable levels

This manual is related to the following products: