pef20320 Infineon Technologies Corporation, pef20320 Datasheet - Page 195

• Manufacturer Part Number: pef20320
• Description: Multichannel Network Interface Controller For Hdlc With 32 Channels
• Manufacturer: Infineon Technologies Corporation

Figure 93
Insertion of additional Information
To make efficient use of the available bandwidth, the parallel use of several B-channels
is one of the routing strategy’s goals. Every Ethernet frame is divided into several parts
because the LAN controller stores the received data in several receive descriptors, if
necessary. The frame is then sent via the ISDN by using a separate B-channel for every
LAN receive descriptor. To ensure that the parts of the Ethernet frame will be
reassembled in correct order, every part of the Ethernet frame is supplied with additional
information. That additional information has to be extracted before reassembling the
frame. In Figure 93 an example of one Ethernet frame consisting of three descriptors,
spread over two B-channels, is shown. The additional information contains the frame
number, the descriptor number and the information, whether the frame is completed. To
simplify the extraction of the additional information every frame part and its additional
information are sent in one HDLC frame.
User’s Manual
ISDN
64 kbit/s
each Channel
Ch1
Ch
2
Frame
Count
Frame
Count
EOF = 0
EOF
1 =
Descr
Count
Descr
Count
fe = SET
fe
=
SET
0
1
Frame
Count
195
EOF
1 =
Descr
Count
fe
=
SET
0
2
LAN
max 10 Mbit/s
1
EOF = SET
Application Notes
PEB 20320
2
ITS08291
01.2000