Nortel Networks Corporation

David Edward Mercer

A Julian Craddock

Ian Alexander Macfarlane

Eric W Parsons

Arthur Julian Craddock

Brian S Major

A communication protocol stack apparatus and method determine the aggregate maximum header and trailer lengths(H, T) and a payload size(P) for each layer of the protocol stack and pre-allocate for each layer one or more buffers of a length equal to the sum of &ldquo;H&rdquo;, &ldquo;T&rdquo; and &ldquo;P&rdquo;. The layer copies receiving data into the pre-allocated buffer at a position determined by &ldquo;H&rdquo;, and copies its header and trailer immediately before and after the data in the buffer. The layer sets two references. The next lower layer copies its header and trailer into the buffer at the positions determined by the references and updates the references. The process is repeated until the lowest layer and data between the references is copied to a physical device for transmission.

Communication protocol stack apparatus and method of implementing same

Using a server to provide access to a plurality of unrelated types of services, to a user communicating from a remote terminal to the server, by detecting a service access command sent from the user, the service access command comprising an indication of a service type, the service access command having a syntax which uses only alphanumeric characters, or '#' or '*' characters. Interpreting the command involves extracting the service type, to detect if the command further comprises one or more parameters relating to the service, extracting any such parameters and initiating the provision of the selected service. By having a server which understands commands in a form having a syntax using a limited set of characters, service access from telephones or terminals with smaller keyboards, becomes easier.

Service access using limited set of characters

To transmit a stream of data packets over a physical channel, virtual channels for each data type (e.g. video, graphics, text) are created and mapped onto the physical channel based on a priority assigned to each virtual channel. Each virtual channel is also assigned a quality of services (QoS). A channel controller is allocated to each virtual channel. These channel controllers are connected to a dispatcher which receives the stream of data packets and distributes the data packets to the channel controllers based on the virtual channel to which the channel controllers are allocated. Should a channel controller encounter degradation in a transmission which reduces QoS below the specified values, a QoS parameter is adjusted. If this action does not achieve the specified QoS, the channel warns the dispatcher. The dispatcher, upon receipt of the warning, may, depending on the data type, reduce that channel controller's specified QoS or another channel's QoS. If the dispatcher takes no action, the controller degrades the data to achieve the necessary QoS.

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Stittsville, Canada

David Edward Mercer