User Manual
U-SYS IAD108 Integrated Access Device
Chapter 6 ADSL Service
Configuration
6-13
upper network. The ADSL subboard only transmits layer 2
messages transparently as a bridge.
When the IAD108 networks with the upper DSLM (such as
Huawei’s MA5100) and BAS (such as ISN8850), and provides ADSL
services, and the ADSL subboard works in the bridging mode, the
protocol stack is as shown in Figure 6-3.
TCP/UDP
IP
PPP
ETHER
1483B
ATM-ALL5
ATM
ETHER
ATM
TCP/UDP
IP
PPP
ETHER
1483B
ATM-ALL5
ATM
PPP connection
User side of
the terminal
Equipment side of
the central office
User PC
IAD108 ADSL subboard
DSLAM
BAS
(1)
(2)
(3)
(1): Network cable/Ethernet packet
(2): PSTN telephone line/ATM cell
(3): Optical fiber/ATM cell
Figure 6-3
Protocol stack in the bridging mode
6.3.2 Networking Examples
Figure 6-4 and Figure 6-5 show networking examples of the
IAD108 ADSL subboard, in the bridging mode.
z
In Figure 6-4, the user PC initiates the PPP connection and
accesses the broadband network in the ADSL mode.
z
In Figure 6-5, the IAD108 initiates the PPP connection and
accesses the broadband network in the ADSL mode.