802.1H is Cisco Proprietary and that it is a bit more effecient than RFC1042
Data packets that are not 802.2 packets must be formatted to 802.2 via 802.1H or RFC1042. Cisco Aironet equipment uses 802.1H because it provides optimum interoperability.
802.1H - This default setting provides optimum performance for Cisco Aironet wireless products.
RFC1042 - Use this setting to ensure interoperability with non-Cisco Aironet wireless equipment. RFC1042 does not provide the interoperability advantages of 802.1H but is used by other manufacturers of wireless equipment.