Cisco Technology, Inc.

Praneet Bachheti

Amit S Phadnis

Anuradha Karuppiah

Pankaj Vyas

A gateway device providing a search utility to determine both NAT information and forwarding information ('both pieces of information') in a single search operation. The single search operation may be implemented using a single table storing both pieces of information necessary for processing a packet. As a result, both pieces of information can be potentially retrieved in a single memory access. Due to the single (or few) memory access, the throughput performance of a gateway may be enhanced. In an embodiment, the gateway is implemented as a service selection gateway which provides connectivity between multiple remote systems and service domains. The NAT/forwarding information is partitioned according to service domains such that the information needed to process packets from/to the same service domain is contained in the same table.

Forwarding packets in a gateway performing network address translation (NAT)

A gateway using multiple NAT tables to translate network addresses (e.g., Internet Protocol Addresses). The gateway may comprise a service selection gateway connecting remote systems to service domains. The gateway translates local addresses of remote systems to external addresses, and vice versa. The external addresses (bound to the respective local addresses) may be provided by the service domains. The NAT information is partitioned according to service domains such that the external addresses related to the same service domain are stored in the same NAT table. If there is no overlap of external addresses provided by two service domains, the two service domains may share the same NAT table. Due to the partitioning of the NAT information, each table may be limited to be of small size, and the accesses to individual tables may be fast. As a result, a gateway may be able to process and forward packets quickly.

Network address translation in a gateway

A network device (e.g., network access server or home gateway) providing different QOS (quality of services) to different layer-3 datagrams when transporting on tunnels. A tunnel may be implemented to provide different QOS to different packets depending on the packet header. The network device examines the header of each datagram to determine the specific QOS to be provided. At least the data portion in the datagram is encapsulated for transportation on the tunnel. The encapsulated data portion in turn is encapsulated in the form of one or more packets, with the packet format to reflect the QOS determined for the datagram. When the tunnel is implemented on UDP/IP and the datagram is an IP (Internet protocol) datagram, the TOS/Precedence bits of the IP datagram may be copied into the precedence/TOS bits of the UDP/IP packet(s).

Providing different QOS to layer-3 datagrams when transported on tunnels

An aggregation device providing different QOS to different point-to-point sessions. Multiple virtual circuits, each to provide different QOS, may be provisioned. The aggregation device may be configured to indicate the desired QOS for each point-to-point session and the data related to each point-to-point session may be assigned to a virtual circuit providing the closest matching QOS. Alternatively, a service provider may statically specify the specific virtual circuit on which the data related to a specific point-to-point session is to be transmitted. Each point-to-point session receives a QOS provided by the assigned virtual circuit. As the content of each datagram received on a point-to-point session may not need to be examined for the purpose of assignment to a virtual circuit, an aggregation device may forward datagrams quickly.

Growing community of inventors

San Jose, CA, United States of America

Praneet Bachheti