Metaswitch Networks Limited

Steven Kennedy

Nicholas Peter Larkin

Colin Tregenza Dancer

Andy Tylee

Alastair Mitchell

An apparatus and a method for processing a received data packet are provided. The method involves determining whether the received data packet is to be recorded and applying to the packet a virtual LAN identification tag from a first group of one or more predetermined virtual LAN identification tags if it is determined that the packet is to be recorded. A recording management system is also provided, including an apparatus and a forwarding network element. The forwarding network element is arranged to inspect as received data packet and determine a virtual LAN identification tag of the packet. The forwarding network element is further arranged to cops the data packet if the virtual LAN identification tag of the packet is in the first group and to send the copy of the data packet to a recording element.

Packet recording

Multiple session initiation protocol (SIP) devices connected to a server via a network may attempt to initiate a process (such as SIP registration) at approximately the same time as each other, by sending SIP messages (e.g. 'REGISTER' messages) towards the server substantially simultaneously. Depending on the number of devices and the resources of the server, the server may not be able to process all of the messages without crashing. An interposed network element, such as a session border controller (SBC), may prevent some of the messages from reaching the server, to stop the server from crashing. However, some messages may be of higher priority than others. The invention provides a way of differentiating between messages to assist in prioritising messages with higher priority over others.

Prioritising SIP messages

An apparatus in a LAN has first and second hardware interfaces to connect to the LAN. First and second monitoring request messages are transmitted to one or more devices in a first VLAN and one or more devices in a second VLAN respectively, via both the first and second hardware interfaces. The monitoring request messages use the Address Resolution Protocol (ARP) or the Neighbor Discovery Protocol (NDP). First and second monitoring response messages are received via the first and/or second hardware interfaces in response to the first and second monitoring request messages respectively. A selection is made between the first and second hardware interfaces for performing data communication, based on the first and second monitoring response messages. The selection is performed independently for data communication via the first and second VLANs based on at least one characteristic of the first and second monitoring response messages respectively.

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Enfield, United Kingdom

Steven Kennedy