peb20550 Infineon Technologies Corporation, peb20550 Datasheet - Page 21

• Manufacturer Part Number: peb20550
• Description: Extended Pcm Interface Controller
• Manufacturer: Infineon Technologies Corporation

1.7.1.4 Mixed D-Channel Processing, Signaling Decentralized,
Another possibility is a mixed architecture with centralized packet data and decentralized
signaling handling. This is a very flexible architecture which reduces the dynamic load of
central processing units by evaluating the signaling information on the line card, but does
not require resources for packet data handling. Any increase of packet data traffic does
not necessitate a change in the line card architecture, the central packet handling unit
can be expanded.
In this application IDECs are employed to handle the data on the D-channel. The IDECs
separate signaling information from data packets. The signaling messages are
transferred to the P, which in turn hands them over to the group controller using the
HSCX.
The packet data is processed differently. Together with the collision resolution
information it is transferred to one IOM-2 port of the EPIC. The EPIC switches the
channels to the PCM-highway, optionally combining four D-channels to one 64-kbit/s
channel. In this configuration one IOM-2 interface is occupied by IDECs, reducing the
total switching capability of the EPIC-1 to 24 ISDN-subscribers.
Figure 8
Line Card Architecture for Mixed D-Channel Processing
Semiconductor Group
Sig.
Data
Packet Data Centralized
IOM -2
IDEC
p - Data
P
R
R
Interface
IDEC
Signaling
P
+
R
Coll
P
EPIC
B, P, C
HSCX
21
R
B
S
B
Example Frame Structure
PCM
Highway
Signaling
Highway
...
B
Packet
Data
P
B
PEB 2055
PEF 2055
Collision
Overview
Data
C
ITS09536
B