APC IP DSLAM Guía de usuario descargar pdf (Pagina 36)

EDA 1200 System Overview

The classification tags included in downstream frames may originate from a

Voice Gateway or a Service Provider’s PoP or they may be the result of a

conversion performed at the edge of the EDA 1200 network. The classifying

nodes in the network are illustrated in Figure 22 on page 32.

Figure 22 Traffic Classification in an EDA 1200 Network

3.2.2 Differentiated Services

The principle of differentiated services is that every single switch or router,

as an autonomous unit, decides the order, in which packets or frames are

forwarded on the transmission link. The decision is based on the classification

(p-bit) of the packet or frame, and the QoS policy.

The differentiated services implementation used in the Ethernet is according

to the IEEE 802.1Q specification, specifying 8 values using three bits, the

so-called p-bit. The p-bit value indicates the classification of the frame.

The operation of a differentiated services based forwarding process of a

network element using two priority levels (Classes of Service), one for voice

and one for data is illustrated in Figure 23 on page 33.

1/1551-LZA 101 464-V1 Uen C 2009-12-17

1 2 ... 31 32 33 34 35 36 37 38 39 40 41 ... 66 67

Sin comentarios

APC IP DSLAM Guía de usuario Pagina 36