RFC 1375 (rfc1375) - Page 2 of 7

Suggestion for New Classes of IP Addresses

RFC 1375              New Classes of IP Addresses           October 1992


   network to allow up to 254^3 local machines [1].  The Class B network
   assigns a somewhat smaller address space for the particular network
   to allow up to 254^2 local machines.  The Class C network assigns a
   still smaller address space for the particular network to allow up to
   254 local machines.

   This memo proposes to assign part of the unused Class C address space
   for smaller networks than are currently available.  The term "Class
   D" is used for the "multicast" capability and addresses in "Class E"
   are reserved for future use.  Therefore, these new features for which
   capability is to be added is being referred to as classes F, G, H and
   K.

Suggestion for new IP address classes

   The most worrisome problem which appears in the literature is the
   possibility of running out of address space for IP addresses. Various
   schemes are being suggested such as subrouting, introduction of
   additional bits, and other possibilities.

   There is an even more serious matter.  In all probability, I suspect
   that eventually the Internet backbone will either become available to
   anyone who wants to use it (like public highways) and the costs paid
   for out of taxes or some other method which gets someone else to pay
   for it, or eventually the Internet will be fully commercialized and
   made available to anyone who wants to buy a permanent connection.
   With the cost of hardware and connections dropping, some Computer
   Bulletin Board Systems (BBSs) which are currently accessible via
   telephone call may become accessible via TELNET or FTP.  When a 9600
   baud connection can be obtained for around the price of a phone line,
   the demand for internet access will skyrocket.  This almost certain
   eventual availability to virtually anyone who wants a connection will
   cause an even greater demand for internet addresses, which will
   exacerbate this situation.  One problem is in the granularity of IP
   addressing, in that the smallest possible IP address one may obtain
   allows for as high as 254 IP addresses.  If someone wanted only to
   put four or five computers on the Internet, more than 240 addresses
   are wasted.

   Many smaller installations would probably be interested either in
   placing their computers and/or servers on the Internet (and perhaps
   helping to pay the cost of running it) or in being able to access the
   Internet directly, and perhaps making facilities on their machines
   available to others; the problem being that IP addresses on Internet
   are not readily available to small classes of users.  Also, the
   possibility exists of eventually placing non-computer and output-only
   devices such as printers, facsimile machines, and visual pagers
   directly on the Internet to allow people to send a message to a local



Robinson