Packet Transfer Mode ({{bibref|G.993.1|Annex H}}). This object contains the {{object|Link}} interface. PTM link-layer table (a stackable interface object as described in {{bibref|TR-181i2|Section 4.2}}). Models a layer 2 variable-sized packet interface. A PTM Link entry is typically stacked on top of either a {{object|##.FAST.Line}}, {{object|##.DSL.Channel}}, or a {{object|##.DSL.BondingGroup}} object. When a ''PTM Link'' interface is used, a lower-layer {{object|##.DSL.Channel}} interface MUST be configured with PTM encapsulation (see {{param|##.DSL.Channel.{i}.LinkEncapsulationUsed}}). The MAC Address of the interface. Note: This is not necessarily the same as the Ethernet header source or destination MAC address, which is associated with the IP interface and is modeled via the {{param|##.Ethernet.Link.{i}.MACAddress}} parameter.