This object is the identifier of a DS1/E1 Interface on a managed device. If there is an ifEntry that is directly associated with this and only this DS1/E1 interface, it should have the same value as ifIndex. Otherwise, number the ds1LineIndices with an unique identifier following the rules of choosing a number that is greater than ifNumber and numbering the inside interfaces (e.g., equipment side) with even numbers and outside interfaces (e.g, network side) with odd numbers. The supported ranges depend upon the type of the card(4 port/8 port etc): For 4 port card : 1 - 4 For 8 port card : 1 - 8 For 2 Port Channelized card : 56 (28*2).