Routing over Large Clouds (rolc)

Status: Concluded May, 1996 
 Andy Malis 
Description of Working Group:
NOTE: This WG combined with IPATM to form the ION WG.
Summary: This group is created to analyse and propose solutions to
those problems that arise when trying to perform IP routing over large
``shared media'' networks. Examples of these networks include SMDS, 
Relay, X.25, and ATM.
   Internetwork Layer: To avoid confusion with multiple meanings of
   ``network'' layer, we will use the term ``Internetwork'' layer to
   unambiguously refer to that layer at which IP runs. This is the
   layer at which IP routing functions. This is also the layer at which
   CLNP, DECnet, etc. run.
Large cloud:  A collection of ``end-points'' be they routers or hosts,
   connected over a fabric such that communication can be established,
   in the absence of policy restrictions, between any two such
   entities. This communication within a cloud takes place using
   addressing and capabilities below the ``Internetwork'' layer.
The connectivity may or may not require circuit setup before
communication. Such a collection is considered large if it is
infeasible for all routing entities on such a ``cloud'' to maintain
``adjacencies'' with all others. Examples include, but are not limited
to, ATM, Frame Relay, SMDS, and X.25 public services.
The group will investigate the operation of IP routing protocols and
services over ``Large Clouds.'' Whenever possible, solutions shall be
applicable to a range of ``cloud'' services. That is, the goal is a
single solution applicable to multiple kinds of large ``clouds'' be they
public or private, and independent of the specific technology used to
realize the ``cloud'' (even a very large bridged Ethernet). It is also 
objective that solutions, where possible, apply to network layer
protocols other than IP.
The problems the group will cover are:
A) The architectural implications of allowing direct communication
   between entities which do not share a common IP network number. The
   group will also entertain proposals on the use of a common IP network
   number. If (as many believe) it is infeasible, an effort to document
   the difficulties will be made.
B) The routing/information protocol required to allow direct
   communication between two entities which were not directly
   exchanging routing information.  This will include address
   resolution.  The solution must couple closely to routing. It must
   take into account realistic connectivity policies.
C) Operation of existing protocols between peers on such clouds. Are
   any changes necessary or desirable?  If changes are required, they 
   be proposed to the relevant working group.
D) Consideration of how policy restrictions and constraints (such as
   access control and policy-based routing paths) affect A, B, and C.
The group will also review the applicability of the work to ISDN and
POTS. These technologies have a prima-facia difference, in that the
number of simultaneous connections is much smaller. The implications of
this for routing and relaying at the Internetwork layer will need to be
explored further.

Request for Comments:

  • RFC1735 NBMA Address Resolution Protocol (NARP) (Experimental)
  • RFC1937 "Local/Remote" Forwarding Decision in Switched Data Link Subnetworks (Informational)