RFC 2171 (rfc2171) - Page 3 of 9


MAPOS - Multiple Access Protocol over SONET/SDH Version 1



Alternative Format: Original Text Document



RFC 2171                         MAPOS                         June 1997


           +------+                                +---------------+
           | Node +--------------------------------+               |
           +------+                                |               |
                                                   |               |
           +------+                                |               |
           | Node +--------------------------------+               |
           +------+                                |               |
                                                   | Frame Switch  |
           +------+                                |               |
           | Node +--------------------------------+               |
           +------+                                |               |
                                                   |               |
           +------+                                |               |
           | Node +--------------------------------+               |
           +------+                                +---------------+

                 (b) Point-to-Multipoint configuration


           +--------+                      +--------+
           | Frame  +----------------------+ Frame  |
           | Switch +--------+    +--------+ Switch |
           +--+-----+      +-+----+-+      +--------+
              |            | Frame  |                      +--------+
           +--+-----+      | Switch |      +--------+      | Frame  |
           | Frame  |      +-----+--+      | Frame  +------+ Switch |
           | Switch |            +---------+ Switch |      ++-------+
           +-------++                      +--------+       |
                   |________________________________________|

                  (c) Switching cluster configuration

                   Figure 1. Possible configurations

   Each port on a switch has an unique identifier within the switch. A
   node connected to a switch port must inherit the address of the port.
   That is, the node address is equal to the port identifier and is
   unique within the switch.

   In a switch cluster, a node address is subnetted. The high-order
   bits, the part where the corresponding bits in the "subnet mask" are
   1, indicate the switch address.  The remaining low-order bits
   indicate the unique node address within the switch. The two fields
   form an unique address for a given node.

   In either case, the address may be configured manually into a node
   interface, or automatically by the address assignment mechanism
   described in [5].



Murakami & Maruyama          Informational