Script-controlled egress packet modifier

A method comprising:

• receiving a packet onto an egress packet modifier, wherein the packet is received as a sequence of parts;
• receiving a script code onto the egress packet modifier;
• using the script code to generate a plurality of opcodes;
• supplying the opcodes to a pipeline of processing stages thereby configuring the pipeline;
• passing the sequence of parts of the packet through the pipeline of processing stages such that each processing stage can perform a selectable one of a plurality of modifications on each part of the packet, wherein the plurality of modifications includes a replace modification in which bits of a part of the packet are replaced with other bits, wherein the plurality of modifications includes an insert modification in which bits are inserted into a part of the packet, wherein none of the processing stages of the pipeline fetches instructions, decodes the instructions, and executes the instructions;
• and
• receiving the sequence of parts from the pipeline and outputting the packet from the egress packet modifier to an egress MAC (Media Access Control) processing circuit.

An egress packet modifier comprising:

• an input port through which the egress packet modifier receives a packet and a script code;
• an output port;
• and
• means for using the script code to generate a plurality of opcodes, for supplying the opcodes to a pipeline of processing stages, and for pipeline processing parts of the packet through the pipeline, wherein each processing stage performs a selectable one of a plurality of modifications as determined by a corresponding one of the opcodes, wherein the plurality of modifications includes a replace modification in which bits of a part of the packet are replaced with other bits, wherein the plurality of modifications includes an insert modification in which bits are inserted into a part of the packet, wherein none of the processing stages of the pipeline fetches instructions, decodes the instructions, and executes the instructions, and wherein the means is also for outputting the packet via the output port.