2.1.3.1.6 Link Speed Determination
The Group Policy client estimates the link speed of the network between the Group Policy client and Group Policy by implementation-specific means. See [MS-GPOL] section 2.2.6 for link speed determination. The implementation can send a message to determine link speed by using ICMP as a transport, but it must support at least 500-byte packets, as described in [RFC792]. If the determined link speed ([MS-GPOL] section 3.2.5.1.9) is below an implementation-defined threshold, the implementation should not invoke any bandwidth-intensive protocol extension sequence. See [MS-GPOL] section 3.2.5.1.10 for more information.