A domain name resolution method includes: obtaining a domain name resolution request packet; caching the obtained domain name resolution request packet to a first cache area; modifying, in the first cache area, header data included in the cached domain name resolution request packet, to obtain header data of a domain name resolution reply packet corresponding to the cached domain name resolution request packet; extracting a requested record type and a domain name to be resolved in the cached domain name resolution request packet; searching a second cache area for pre-cached reply data that corresponds to the extracted domain name and that belongs to the extracted record type; and combining the pre-cached reply data with the domain name resolution request packet obtained through modification, to obtain a domain name resolution reply packet.

A call set-up system sets up a call, which may be a voice call, between terminals through a plurality of packet switched networks using call agents. The networks are interconnected by network address translation (NAT) devices, and the messages to successive call agents include media addresses in the associated networks for the actual data packets of the call when it has been set up. The call set-up message includes the media address sent to at least some preceding call agents enabling NAT resources to be saved. The call agents can be incorporated into NAT devices, and the media addresses can be encrypted or in the form of a reference.

A method for a hypervisor to implement flow-based local egress in a multisite datacenter is disclosed. The method comprises: determining whether a first data packet of a first data flow has been received. If the first data packet has been received, then the hypervisor determines a MAC address of a first local gateway in a first site of a multisite datacenter that communicated the first data packet, and stores the MAC address of the first local gateway and a 5-tuple for the first data flow. Upon determining that a response for the first data flow has been received, the hypervisor determines whether the response includes the MAC address of the first local gateway. If the response includes a MAC address of another local gateway, then the hypervisor replaces, in the response, the MAC address of another local gateway with the MAC address of the first local gateway.

Systems and methods for source address transparency in a communication network include a proxy server and an IP gateway in which the proxy server receives a traffic flow from an end-user device and determines a source address for the detected traffic flow; the proxy server further creates a virtual interface corresponding to the end-user device from which the traffic flow was received and uses the virtual interface for that end-user device to exchange data between the end-user device and a designated web server. The virtual interface sends the traffic flow to the designated web server using the source address that is the same as or a variant of the source address for the end-user device from which the traffic flow was received.

A domain name resolution method includes: obtaining a domain name resolution request packet; caching the obtained domain name resolution request packet to a first cache area; modifying, in the first cache area, header data included in the cached domain name resolution request packet, to obtain header data of a domain name resolution reply packet corresponding to the cached domain name resolution request packet; extracting a requested record type and a domain name to be resolved in the cached domain name resolution request packet; searching a second cache area for pre-cached reply data that corresponds to the extracted domain name and that belongs to the extracted record type; and combining the pre-cached reply data with the domain name resolution request packet obtained through modification, to obtain a domain name resolution reply packet.

A hardware network accelerator comprises a plurality of Ethernet communication interfaces, a plurality of memories, and a further memory. Each memory stores records comprising destination IP data identifying a destination IP address range. The further memory stores further records, wherein each record comprises next-hop data indicating a next-hop IP address, next-hop enable data, and network port data indicating an Ethernet communication interface. Each Ethernet communication interface is configured to obtain an IP packet, access in parallel the memories in order to read the records, select a record having a destination IP address range containing the destination IP address of the IP packet, read the further record associated with the selected record from the further memory, and select the indicated Ethernet communication interface. The selected Ethernet communication interface is configured to transmit an Ethernet frame comprising the IP packet based on the next-hop enable data and next-hop data.

A hardware network accelerator comprises a plurality of Ethernet communication interfaces, a plurality of memories, and a further memory. Each memory stores records comprising destination IP data identifying a destination IP address range. The further memory stores further records, wherein each record comprises next-hop data indicating a next-hop IP address, next-hop enable data, and network port data indicating an Ethernet communication interface. Each Ethernet communication interface is configured to obtain an IP packet, access in parallel the memories in order to read the records, select a record having a destination IP address range containing the destination IP address of the IP packet, read the further record associated with the selected record from the further memory, and select the indicated Ethernet communication interface. The selected Ethernet communication interface is configured to transmit an Ethernet frame comprising the IP packet based on the next-hop enable data and next-hop data.

A communication system including a first address notification apparatus provided in a first communication network, and a second address notification apparatus provided in a second communication network, wherein the first address notification apparatus includes means that receives an address request from a terminal that can communicate with the first address notification apparatus and with the second address notification apparatus, obtains a source address from the address request, and transmits a response including the source address to the terminal, and the second address notification apparatus includes means that receives an address request from the terminal, obtains a source address from the address request, and transmits a response including the source address to the terminal.

A network address is allocated for a guest virtual machine (VM) of a computing device by the host operating system. The network address is externally accessible from an external network coupled to the computing device. An indication is received, from the guest VM, that the guest VM is using the network address. The network address as used by the guest VM matches the network address as exposed by the host operating system on the external network. A network transmission, from the external network, is received that is directed to the network address. Responsive to the indication that the guest VM is using the network address, the network transmission is transferred to the guest VM.

Systems, methods, and apparatus are herein disclosed for enabling direct communication between two IRC clients without the use of an IRC server once the connection is established. In one instance this can involve a gateway electing to not mangle or not perform NAT on a private IP address of a sending client as a DCC request is passed to the IRC server. In another instance this can involve a gateway mangling or performing NAT on a sender public IP address of a DCC request after it has been passed to the IRC server and returned to the gateway. The clients can be SoftAP clients. The gateway can determine when to mangle and when not to mangle IP addresses using a database that include identifiers of IRC clients on a subnet along with respective IRC servers for those IRC clients.