It is recommended that a provider implement on a local basis a relative prioritization scheme for sockets within a group. This would not have any impact on the on-wire protocol and thus does not affect interoperability. The Windows Sockets 2 prioritization scheme, which is defined only across the sockets within a single group, is both meaningful and useful when the information associated with group member sockets form an exclusive multiplex across an underlying point-to-point connection such as a telephone call, ATM switched virtual circuit, or other circuit switched connection. Decisions on how to establish a priority relationship between sockets not in the same group or not in any group are left up to the service provider implementor. Where the underlying transport protocol encompasses group semantics, it is advantageous to have the group prioritization scheme be implemented on a bilateral basis.
It is also recommended that a provider support group QOS for at least best effort service levels.