Data structures for supporting packet data modification operations

A processor readable medium storing a data structure for supporting one or more packet modification operations is provided. The data structure has a pointer to a sequence of one or more commands stored in a first memory area and implementing one or more packet modification operations. The data structure also has a pointer to a burst of one or more data or mask items stored in a second memory area for use by the one or more commands. A method of performing one or more packet modification operations on a packet is also provided. This packet is associated with a data structure link. In this method, a data structure corresponding to the data structure link is retrieved. This data structure has the format described above. A packet modification system utilizing a data structure having this format is also provided.