In the context of EDI, the term Spoke usually refers to the seller in a B2B transaction. The buyer is referred to as a Hub.

Merriam-Webster Online Dictionary
spoke ()
spoke (noun)
1.
a) any of the small radiating bars inserted in the hub of a wheel to support the rim
b) something resembling the spoke of a wheel
2.
any of the projecting handles of a boat's steering wheel
spoke (verb)
transitive verb
to furnish with or as if with - spokes