RFC 1051 (rfc1051) - Page 1 of 4

Standard for the transmission of IP datagrams and ARP packets over ARCNET networks

Network Working Group                                    P. Prindeville
Request for Comments:  1051                           McGill University
                                                             March 1988


            A Standard for the Transmission of IP Datagrams
                  and ARP Packets over ARCNET Networks


Status of this Memo

   This RFC specifies a standard protocol for the Internet community.
   Distribution of this memo is unlimited.

Introduction

   This RFC specifies a standard method of encapsulating Internet
   Protocol (IP) [1] and Address Resolution Protocol (ARP) [2] datagrams
   on an ARCNET [3].

Acknowledgements

   The author wishes to express thanks to Robert Craig of the McGill
   University Computing Centre and Bruce Hughes of Datapoint Corporation
   for their generous support of facilities and information.  I also
   extend my gratitude to the readers of the PCIP mailing list for their
   helpful ideas and comments.

Frame Format

   IP and ARP datagrams are transmitted in standard ARCNET packets.  As
   required by Datapoint Corporation, the first octet of the data field
   is reserved for the network layer protocol identification (the
   "system code" in Datapoint nomenclature), and must contain the value
   240 (F0 hex) for IP or 241 (F1 hex) for ARP.  The ARP hardware
   address type for ARCNET is 7 [9].

   ARCNET supports packet formats containing 1-253 octets of data
   (normal format) and 257-508 octets of data (extended format),
   inclusive of system code.  Note that there exists a range of data
   lengths (254-256) which are 'forbidden'.  IP packets within this
   range should be padded (with octets of zero) to meet the minimum
   extended packet size of 257 data octets.  This padding is not part of
   the IP packet and is not included in the total length field of the IP
   header.






Prindeville