3com 5000 ATM Manual De Usuario
2-6
C
HAPTER
2: LAN E
MULATION
O
VERVIEW
Packets Versus Cells
The ATM Backbone SwitchModule converts Ethernet- and
FDDI-originated packets to and from ATM cells.
FDDI-originated packets to and from ATM cells.
Figure 2-6 illustrates the conversion of SwitchModule packets to and
from ATM cells.
from ATM cells.
Figure 2-6 Converting SwitchModule Packets to and from ATM Cells
To ATM
From
ATM
ATM
HDR
53 Octets
53 Octets
53 Octets
48 Octets
48 Octets
48 Octets
SwitchModule packet
Cells
Segmentation/
Reassembly
Reassembly
Padding and
error correction
error correction
HDR = ATM Cell Header (5 octets)
HDR
HDR