Multiplexing allows multiple signals or users to use the same portal to access a program or application. The term was originally used to describe multiple telephone calls that can be carried simultaneously on one wire.
When licensing software by the user metric – named, authorized, application- vendors define users as the number of unique individuals accessing the program on the ‘front end’. The number of access points for those users is not a factor for these sorts of user licensing. This would also cover the concept of ‘shared id’ set-ups in your environment. 100 users sharing one log-on and password are still 100 users. Also be aware that devices may also require a user license; it is not always an individual person.
Here is a sample of what a license metric definition referencing multiplexing may look like:
(this is from IBM for authorized user, http://www-01.ibm.com/software/passportadvantage/about_software_licensing.html)
[IBM’s] Authorized User is a unit of measure by which the Program can be licensed. An Authorized User is a unique person who is given access to the Program. The Program may be installed on any number of computers or servers and each Authorized User may have simultaneous access to any number of instances of the Program at one time. Licensee must obtain separate, dedicated entitlements for each Authorized User given access to the Program in any manner directly or indirectly (for example: via a multiplexing program, device, or application server) through any means. An entitlement for an Authorized User is unique to that Authorized User and may not be shared, nor may it be reassigned other than for the permanent transfer of the Authorized User entitlement to another person.
Note: Some programs may be licensed where devices are considered users. In that case the following applies: Any computing device that requests the execution of or receives for execution a set of commands, procedures, or applications from the Program or that is otherwise managed by the Program is considered a separate User of the Program and requires an entitlement as if that device were a person.