This attribute represents the association between an atmLink and an existing atmLinkTP. An atmLink links exactly 2 atmLinkTPs; an atmLinkTP is linked by zero or one atmLinks. This attribute points to one of the two atmLinkTPs. In this case the z-LinkTP points to a single atmLinkTP object instance. Usually this attribute points to a single termination point. However, in cases where the NE view is also supported and the atmLink is supported by more than one server trail, this attribute may point to more than one termination point.
Sources for this description
ATM Forum M4 official network view CMIP specifications