Patent ID: 6128666
Filing Date: 2000-10-03
Classification: H04L

Abstract:
In a packet switch, as apparatus for selective header field replacement comprising:an input port process (IPP) coupled to receive an input packet comprising a header, data and cyclic redundancy code (CRC), the IPP further comprising a buffer configured to temporarily store the input packet;a database configured to store information regarding packets and routes;a search engine coupled between the IPP and the database, the search engine coupled to receive the header and configured to search the database to determine information regarding a type of the input packet;the IPP further configured to output the input packet from the buffer and to selectively replace at least one field in the header in response to the information provided by the search engine and selectively output control field information to indicate the need for additional modification of the modified input packet prior to output from the packet switch;an output port process (OPP) configured to receive the selectively modified input packet and the control field information from the IPP, the OPP configured to selectively generate at least one control signal to indicate that the modified input packet is to be further modified prior to output from the packet switch and to output the selectively modified input packet; andan output interface, the output interface coupled to the OPP to receive the at least one control signal and the selectively modified input packet, the output interface configured to output a packet from the packet switch that corresponds to the selectively modified input packet by selectively modifying, in response to the at least one control signal, at least one header field and the CRC prior to transmission of the output packet.