Modular type node apparatus for packet communication

A modular type node apparatus for packet communication comprising:

• a control module;
• a plurality of network interface modules each for communicating packets with a network;
• a plurality of extension module connection interface units each connectable with an extension module;
• and
• a packet switching unit for connecting said network interface modules and said extension module connection interface units to each other and forwarding a packet received from any of said network interface modules or extension module connection interface unit to one of said network interface modules or extension module connection interface units specified by an internal address indicated in an internal header added to the received packet,
• wherein each of said extension module connection interface units comprises:
• a controller for transmitting, when an extension module is connected to said extension module connection interface unit, an address setting message to the extension module, the address setting message indicating a packet address of said control module and a packet address and the internal address to be allocated to the extension module;
• and
• an internal address adding unit for outputting, upon receiving from said extension module a request packet for control data registration having a packet address destined for said control module and indicating a relationship between flow definition information for identifying a packet to be processed by the extension module and the internal address of the extension module,
• the request packet to said packet switching unit in a form of an internal packet with an internal header including an internal address of said control module;
• connection interface units to one of said network interface modules or extension module connection interface units specified by an internal address indicated in an internal header added to the received packet,
• at least one of said plurality of extension module connection interface units being connected with an extension module, wherein:
• said extension module comprises:
• a memory storing flow definition information for identifying a received packet to be processed by the extension module and a service identifier indicating the type of service processing to be provided by the extension module;
• and
• a module controller having a function to issue a request packet for control data registration in its initial operation and
• to execute service processing in response to reception of a packet matching the flow definition information in its steady operation;
• each of said extension module connection interface units comprises:
• a controller for transmitting, when an extension module is connected to said extension module connection interface unit, an address setting message to the extension module, the address setting message indicating a packet address of said control module and a packet address and the internal address to be allocated to the extension module;
• and
• an internal address adding unit for outputting, upon receiving from said extension module a request packet for control data registration having the packet address
• said control module registers, upon receiving said request packet for control data registration from said packet switching unit,
• a table entry indicating the relationship between the flow definition information and the internal address of the extension module indicated in said request packet into a packet forwarding control table to be referred to by each of said network interface modules, and
• each of said network interface modules outputs, upon receiving from a network a packet with header information matching the flow definition information indicated in said packet forwarding control table,
• the received packet to said packet switching unit in a form of an internal packet with an internal header including the internal address corresponding to the flow definition information indicated in said packet forwarding control table.