RFC 2019 (rfc2019) - Page 2 of 6
Transmission of IPv6 Packets Over FDDI
Alternative Format: Original Text Document
RFC 2019 Transmission of IPv6 Packets Over FDDI October 1996
Frame Format
FDDI provides both synchronous and asynchronous transmission, with
the latter class further subdivided by the use of restricted and
unrestricted tokens. Only asynchronous transmission with
unrestricted tokens is required for FDDI interoperability.
Accordingly, IPv6 packets shall be sent in asynchronous frames using
unrestricted tokens. The robustness principle dictates that nodes
should be able to receive synchronous frames and asynchronous frames
sent using restricted tokens.
IPv6 packets are transmitted in LLC/SNAP frames, using long-format
(48 bit) addresses. The data field contains the IPv6 header and
payload and is followed by the FDDI Frame Check Sequence, Ending
Delimiter, and Frame Status symbols.
+-------+ ^
| FC | |
+-------+-------+-------+-------+-------+-------+ |
| Destination FDDI address | |
+-------+-------+-------+-------+-------+-------+ FDDI
| Source FDDI address | header
+-------+-------+-------+-------+-------+-------+ |
| DSAP | SSAP | CTL | OUI | |
+-------+-------+-------+-------+-------+-------+ |
| Ethertype | v
+-------+-------+-------+-------+-------+------+------+
| IPv6 header and payload ... /
+-------+-------+-------+-------+-------+------+------+
FDDI Header Fields:
FC The Frame Code must be in the range 50 to 57 hexadecimal,
inclusive, with the three low order bits indicating the
frame priority. The Frame Code should be in the range 51 to
57 hexadecimal, inclusive, for reasons given in the next
section.
DSAP, SSAP Both the DSAP and SSAP fields shall contain the value AA
hexadecimal, indictating SNAP encapsulation.
CTL The Control field shall be set to 03 hexadecimal, indicating
Unnumbered Information.
OUI The Organizationally Unique Identifier shall be set to
000000 hexadecimal.
Crawford Standards Track