Dsc Communications Corporation

Ross M Schibler

P Kingston Duffie

A Mitchell Topol

Kai Y Yang

An ingress processor (16) includes an ingress controller (34) that controls the flow of asynchronous transfer mode (ATM) cells placed in the ingress cell memory (32) by a cell loader (30). The ingress controller (34) links together ATM cells within the ingress cell memory (32) that correspond to a particular packet. The ingress controller (34) sends the beginning of message cell (BOM) to a route cell buffer (42) for processing by an ingress router (44). The ingress router (44) determines routing information from content addressable memories (72) and routed cache associative memory (73) corresponding to the BOM cell within the route cell buffer (42). A router controller (60) within the ingress router (44) generates a setup ATM cell containing the retrieved routing information and sends the setup ATM cell to the ingress processor (34) through the route cell buffer (42). The ingress processor (34) sends the setup cell, the BOM cell, a transmit agent (48) through a transmit agent cell buffer (46) for transmission out of the ingress processor (16). The transmit agent (48) transmits all subsequent cells of the packet. Routing information for the packet is also stored in a VCI table (50) for use by the transmit agent (48) such that further route determinations for subsequent cells within a packet need not be determined by the ingress router (44).

Method and apparatus for route processing asynchronous transfer mode

An apparatus for generating route information for asynchronous transfer mode (ATM) cell processing includes a route agent (64) that transmits a route request cell in response to a determination that route information for a particular ATM cell is not found within a route cache (62). A route processor (34) receives the route request cell from the route agent (64) and performs a route lookup operation within a set of routing tables (32). A master processor (30) builds and maintains the routing tables (32) in response to network and switch topologies received from and generated by an administration module (14). The route processor (34) obtains route information, such as destination card and port number, from the routing tables (32) and generates a route response cell containing the appropriate route information. The route agent (64) receives the route response cell from the route process (34) and updates the route cache (62) as determined by a least recently used manager (65). Processing continues on the ATM cell using the newly generated route information and remaining ATM cells within a packet are processed with the newly generated route information in the route cache (62) without any further routing generation.

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San Mateo, CA, United States of America

Ross M Schibler