PEF2054NV21XT Lantiq, PEF2054NV21XT Datasheet - Page 24

• Manufacturer Part Number: PEF2054NV21XT
• Manufacturer: Lantiq

Specifications of PEF2054NV21XT

• Lead Free Status / Rohs Status: Compliant

PEB 2055
PEF 2055
Overview
1.7.3
Packet Handlers
The EPIC is an important building block for networks based on either central, decentral
or mixed signaling and packet data handling architectures. Its flexibility allows for the
modification of the packet handling architecture according to the changing needs.
Thus it may be useful to add central packet handling groups to a network originally based
on decentral signaling and packet handling. This may be the case if growing data packet
traffic exceeds the initial capacity of the network. The result is a mixed architecture.
On the other hand, increasing packet handling demand on a few dedicated subscriber
lines calls for solutions which back up the capacity at these few decentral line cards.
In both of these cases and several other applications, the EPIC is a powerful device for
solving the problem of packet handling. In most applications it is used together with the
IDEC (ISDN D channel Exchange Controller).
Decentralized and mixed packet handling has already been covered in the line card
chapter. In the following, the centralized signaling/packet handlers built up with the EPIC
will be described.
Central packet handling is used if many subscribers with a generally low demand for
packet switching are to be connected to a system. Concentrating the packet servers for
multiple users eliminates the need to provide a packet server channel for every user. The
overall number of packet server channels can thus be reduced.
In such a central packet handling group, the EPIC performs the switching and
concentrator function. It connects a variable number of PCM highways to the packet
handler internal highway. HDLC controllers are also connected to this internal highway
as illustrated in figure 11.
PCM Highways
A
B
C
D
Packet Handler Internal Highway
R
EPIC
R
R
IDEC
IDEC
C
Centralized Packet Handler Unit
ITS09539
Figure 11
Centralized Packet Handler with a Single Internal Highway Connected to 4 PCM
Highways
Semiconductor Group
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