Section: 5.5.2.1 Use of credit pooling
Content: Credit fragmentation can occur when it is necessary to grant separate quotas. Granting each quota causes some of the user's credit to be reserved at the Server. It is then possible that all the user's credit may be reserved when the user wishes to start using a new service. The new service may then be denied, despite the fact that there remains unused credit in the user's account. To avoid such credit fragmentation and unnecessary load on the server, it is possible for multiple quotas provided to be linked into a credit pool. The client may then consider the quotas to form a single pool of credit, from which all services draw units. The reference to a credit pool includes a translation factor derived from the rating parameter, which translates from units of a specific type (time/volume) to the abstract units in the pool. The use of credit pooling is described in IETF RFC 4006 [402].