|
This patent application as explained by the Inventor, Shakeel Mustafa, relates to the higher layer protocols carrying diverse user information rely upon data-link layer to exchange information among the plurality of data-link devices. Data link layer is identified as Layer 2 in the OSI reference model that facilitates the exchange of user information encapsulated by the higher protocols between data-link devices. As part of covering the wide applications, Shakeel Mustafa, also explains in his application that that most accepted industry standard data-link protocols are Point to Point Protocol (PPP), Frame Relay, HDLC, SDLC in the WAN side, and Ethernet (with different flavors) in the LAN arena. All of these protocols were initially formulated in response to the requirement of carrying data. As the users demand for using multifunctional applications with different transmission characteristics grew these protocols started to show their weakness to fulfill the specific needs of diverse application layer protocols. The data-link protocols historically designed to deliver big chunks of raw data are not well suited to handle and deliver delay sensitive traffic in real time. For example, multimedia applications require that the transmitting data should be delivered with the least delay and a few flip-flops in their payload bits does not cause a major problem. On the other hand, data delivery applications demands that the integrity of the data frames be preserved during the course of transmission. A mere single flip in the payload bit value can lead to discard the entire data segment transmitted by the transport layer. The data frame transmission is well tolerable to jitter and any additional delay. On slow WAN links, low overhead with high payload is another preference of data applications. Multimedia applications relatively transmit small payloads but they are required to carry large protocol overhead conventionally designed to meet data transmission requirements. Beside the preferred method of operation, Shakeel Mustafa, also addresses the impact of service degradation factor for multimedia frames which comes from the serialization delay introduced by relatively large data frames. If a multimedia application frame arrives at a particular instance when the transmission of a data frame is already in progress, the multimedia frame must wait in the queue until the data frame transmission is completed. A large data frame being transmitted on a slow WAN link (e.g., over a modem connection) can take a significantly long time for transmission. For example, a 512 byte frame size being transmitted on a typical 56 kbps modem can take roughly 40 msec to complete its transmission. A delay sensitive multimedia frame has to wait this long before it can even start its transmission. To make this patent application more practical, the inventor Shakeel Mustafa, identifies another class of traffic which does not demand the tight requirements of voice or video but directly involves human interaction with computers. A noticeable delay in these applications response time can decreases productivity and may cause frustration. This traffic type relates to applications like X-Windows, Telnet, http (World Wide Web browsing) etc. The human frustration and loss of productivity which may result because of this excessive delay can be avoided by servicing these applications traffic with a certain priority. Also, when congestion causes packets to be dropped, it can result in many resends.
Related Articles -
Shakeel, Mustafa,
|
