Enterasys atx Betriebsanweisung
B-1
APPENDIX B
PACKET TRANSLATION PROCEDURE
Since the ATX is a multi-media unit, packets are converted from the
different media into a standard canonical format. The Offset field
for the
different media into a standard canonical format. The Offset field
for the
filters
command refers to the canonical format packet.
The exact translation procedure is defined by RFC 1188 and RFC
1042, except for the encapsulation of Ethernet AppleTalk packets
which uses Protocol ID of 00-00-F8 instead of all zeros. For further
information, refer to the RFCs, or to the figures which follow.
1042, except for the encapsulation of Ethernet AppleTalk packets
which uses Protocol ID of 00-00-F8 instead of all zeros. For further
information, refer to the RFCs, or to the figures which follow.
Figure B-1. Packet Translation
Ethernet Frame
DA
SA
Frame Type
Data
FCS
FDDI Frame
FC=asynchronous
SA
DSAP = SNAP
(0xaa)
SSAP = SNAP
(0xaa)
Control = UI
(0x03)
Protocol ID = 0,0,0
followed by frame type
Data
FCS
DA
802.3 Frame
FDDI Frame
DA
SA
Length
DSAP
SSAP
Data
FCS
FC=asynchronous
DA
SA
DSAP
SSAP
Control
Data
FCS
Control