This attribute indicates the current highest version of the Radio Link
Protocol (RLP) protocol negotiated by the Radio Link Protocol
(RLP), during Exchange Information (XID). Valid values are:
0, Single-link basic version.
1, Single-link extended version (for example, extended by data
compression).
The value used for XID negotiations can be provisioned by
component GsmIwfRadioLinkProtocol attribute highestVersion.