Patent ID: 8743915

Claim:
A method of transmitting a packet in an optical transport network, the method comprising: generating, by a packet transport apparatus, a first high order transport unit using a first high order data unit in an order higher than that of a dynamic data unit; transmitting, by the packet transport apparatus, the first high order transport unit to a switching apparatus; extracting, by a first line card of the switching apparatus, the first high order data unit from the first high order transport unit; extracting, by the first line card of the switching apparatus, a lower order data unit in an order lower than that of the first high order data unit from tributary slots of the first high order data unit; switching, by a switching unit of the switching apparatus, in a signal unit of the extracted lower order data unit using the extracted lower order data unit; mapping, by a second line card of the switching apparatus, the switched lower order data unit to tributary slots of a second high order data unit in an order the same as that of the first high order data unit; generating, by the second line card of the switching apparatus, a second high order transport unit using the mapped second high order data unit; and transmitting, by the second line card of the switching apparatus, the second high order transport unit.