Atm Dxi Mode - 3Com SuperStack II PathBuilder S330 Reference Manual

Figure 169 PathBuilder S330/S310 to ATM PVC
PathBuilder
S330/S310
Frame
VP 0
In
Out
DLCI 50
It is also important to select the proper traffic contract from the ATM
switch/service provider. This card should use a VBR or CBR circuit set at the speed
of the connected port. (See Figure 170.)
Figure 170 PathBuilder S330/S310 Traffic Contract
PathBuilder S330/S310
Frame In
1 Mbps
VBR service will work; however the synchronous path will be subjected to possible
discards and delay.
The following subsections describe the supported frame protocol modes in greater
detail.

ATM DXI Mode

ATM DXI mode is used to interconnect a DTE to a DCE. The DTE is typically a
legacy interworking device with limited ATM capability. Through ATM DXI, the
DCE allows the DTE to participate in an ATM network. Figure 171 illustrates a
PathBuilder S330/S310 switch in the ATM DXI network.
Figure 171 DXI Network Connection
DXI DTE
(Router)
DXI protocol defines an open interface between the router and the Data Service
Unit. The Data Service Unit off-loads cell encapsulation services from the Brouter.
This will allow your current brouter to support ATM, simply by supporting V.35 and
High-level Data Link Control (HDLC).
VC 50
ATM
VP 0 VC 50
CBR or VBR at
1 Mbps
1 Mbps
Sustained Cell
Rate
DXI Frames
DXI DCE
(PathBuilder
S330/S310)
Serial Interface
PathBuilder
S330/S310
VP 3
VC 45
VP 3
Out
VC 45
In
ATM Cells
ATM
Network
241