Description: A value which indicates the set of services that
this entity primarily offers.

The value is a bitmask where each bit indicates
whether the entity supports the services at the
corresponding protocol stack layer.  In the context
of the Internet suite of protocols, values should
be calculated accordingly:

bit    layer   functionality
---    -----   -------------
1       1      physical (e.g., repeaters)
2       2      datalink/subnetwork (e.g., bridges)
4       3      internet (e.g., IP gateways)
8       4      end-to-end  (e.g., IP hosts)
64      7      applications (e.g., mail relays)

For systems including OSI protocols, layers 5 and
6  have the values 16 and 32, respectively.

For example, a node which performs primarily routing
functions would have a value of 4.  In contrast, a node 
which is an IP host offering application services would 
have a value of 72 (72 = 8 + 64).  
Common name: Services