routing information indicator (RII)
The RoutingInformation Indicator (RII) consists of a single bit in the MAC address of the source station.
The RII indicator is also called the Source Routing Bit and is the first bit of the source address, the Most Significant Bit( MSB); this bit is therefore lost to the actual address range.
The Routing Information Indicator shows whether the data packet contains any routing information or a routing information field. If the Routing Information Indicator has the value "0" (RII = 0), then the data packet has no routing information field. If RII = 1, on the other hand, a routing information field is present and can be interpreted.