RIF

Routing Information Field

Structure

Routing information is stored in the header of token ring frames in the RIF.

     +---------------+------------------+------------------+------
     | Route Control | Route Designator | Route Designator | ...
     +---------------+------------------+------------------+------
     
             |                                        |
             |                                        |
             |                                        |
             V                                        |
                                                      |
+-----------+--------+-----------+---------------+    |
| Broadcast | Length | Direction | Largest Frame |    |
+-----------+--------+-----------+---------------+    |
   |                                |                 |
   |                                |                 |
   |                                |                 |
   |                                |                 V
   |                                |     +----------+------------+
   |                                |     | Ring Num | Bridge Num |
   |                                |     +----------+------------+
   V                                |
+-----+-----------------------+     |
| 000 | Specific Rout         |     |
+-----+-----------------------+     |
| 100 | All Routes Broadcast  |     |
+-----+-----------------------+     |
| 110 | Single Route Broadcast|     |
+-----+-----------------------+     |
                                    |
                                    V
                               +------------------+----+-----------------------+
                               |Largest Frame Size| MTU| Max IP datagrame Size |
                               +------------------+----+-----------------------+
                               |        000       | 552|         508           |
                               +------------------+----+-----------------------+
                               |        001       |1064|         1020          |
                               +------------------+----+-----------------------+
                               |        010       |2088|         2044          |
                               +------------------+----+-----------------------+
                               |        011       |4136|         4092          |
                               +------------------+----+-----------------------+
                               |        100       |8232|         8188          |
                               +------------------+----+-----------------------+