A method of communication among telephony services using an event context
cache can include, in a messaging telephony service, receiving a
telephony event from a node in the public switched telephony network
specifying a called directory number, a calling directory number, and
service context data. The service context data can be stored as an entry
within the event context cache. The event context cache can be accessible
by at least one other telephony service. The entry can be associated with
a key for the event context cache. The key can be specified by the called
directory number and the calling directory number.