1. A method comprising: receiving a first request for data associated with a first data identifier from a first requesting entity; maintaining mapping information for the first request that associates the first data identifier with the first requesting entity; receiving a second request for the data associated with the first data identifier from a second requesting entity; maintaining mapping information for the second request that associates the first data identifier with the second requesting entity; determining that the first data identifier applies to the first request and to the second request; requesting the data associated with the first data identifier from a data-providing entity in a multiplexed request; receiving a response to the multiplexed request from the data-providing entity, the response including the data associated with the first data identifier; returning a first response to the first request, including accessing the mapping information to include the data associated with the first data identifier in the first response; and returning a second response to the second request, including accessing the mapping information to include the data associated with the first data identifier in the second response.