The default implementation of the System.Web.SiteMapProvider class provides a non-optimized implementation of the SiteMapProvider.GetParentNodeRelativeToCurrentNodeAndHintDownFromParent(int, int) method, calling the SiteMapProvider.GetCurrentNodeAndHintAncestorNodes(int) and SiteMapProvider.HintNeighborhoodNodes(SiteMapNode, int, int) methods; however, site map providers can override the SiteMapProvider.GetParentNodeRelativeToCurrentNodeAndHintDownFromParent(int, int) method and provide an optimized implementation that uses custom caching mechanisms to return the ancestor node and perform an optimized lookup of the other System.Web.SiteMapNode objects.

The walkupLevels parameter is used to specify how many levels of parent and ancestor nodes to traverse when retrieving the target node. If fewer levels exist than are requested, null is returned. The downLevel parameter is used to specify how many levels of descendant nodes from the target ancestor node to retrieve. If preferred, the ancestor and descendant nodes can be linked to the System.Web.SiteMapNode that is returned by the SiteMapProvider.GetParentNodeRelativeToCurrentNodeAndHintDownFromParent(int, int) method, using the SiteMapNode.ParentNode and SiteMapNode.ChildNodes properties.