A value which indicates the set of services that
this entity primarily offers.
The value is a sum. This sum initially takes the
value zero, Then, for each layer, L, in the range
1 through 7, that this node performs transactions
for, 2 raised to (L - 1) is added to the sum. For
example, a node which performs primarily routing
functions would have a value of 4 (2^(3-1)). In
contrast, a node which is a host offering
application services would have a value of 72
(2^(4-1) + 2^(7-1)). Note that in the context of
the Internet suite of protocols, values should be
calculated accordingly:
layer functionality
1 physical (e.g., repeaters)
2 datalink/subnetwork (e.g., bridges)
3 internet (e.g., IP gateways)
4 end-to-end (e.g., IP hosts)
7 applications (e.g., mail relays)
For systems including OSI protocols, layers 5 and
6 may also be counted."
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