B. Pahlevanzadeh

New approach for flow control using PAUSE frame management

Day by day Internet communication and services are experiencing an increase in variety and quantity in their capacity and demand. Thus, making traffic management and quality of service approaches for optimization of the Internet become a challenging area of research; meanwhile flow control and congestion control will be considered as significant fundamentals for the traffic control especially on the high speed network (in the range of Gigabit Ethernet family). The existing IEEE802.3x standard which is applicable to all version of full-duplex Ethernet uses PAUSE frames as MAC control frames to enable or disable frame transmission. As a result regulating data flow at the low level of OSI model assists in minimizing frame loss and preventing latency due to error recovery at the higher layer protocols. However some problems encountered; for instance, it does not distinguish the well-behaved stations from misbehaved stations and it causes a head-of-line problem. Moreover, there is no priority awareness all traffic get equal punishment. The adding overhead and other problems associated with IEEE802.3x have made it become inefficient. Realizing the studies to overcome the problems become important has motivated us to propose a new format of PAUSE frame through an intelligent switch, which includes some new flexible programmable fields, such as predetermined pause-time for particular traffics. So our proposed intelligent switches with its new PAUSE frame are able to distinguish between different types of traffic and in turn, both new PAUSE frame and intelligent switch together provide an efficient flow control approach for high speed networks.

Routing Layer Service Advertisement Approach for MANETs

Finding resources in mobile ad hoc network which is infrastructure less and all of nodes are free to move from a position to new position, is not easy and has a direct relation to the method of storing services information among the network. In this paper we propose a way for advertising and management of resources information in the network that reduce number of communication messages and all services are accessible. We also use a clustering routing protocol to avoid flooding. To reduce message communication we move service advertisement from application layer to routing layer. In this case service advertisement piggybacked hello message and these two processes takes place simultaneous. Our experiment shows that this manner does not have significant overhead.

Per-Priority Flow Control (PPFC) for Enhancing Metro Ethernet QoS

This paper presents a novel scheme called perpriority flow control (PPFC) as an extension to the IEEE802.3x standard using a simple and efficient node buffer management strategy, where a physical channel was divided into several virtual channel based on the bandwidth value (QoS parameter) embedded into the IPv6 flow label field of each flow. Moreover, it investigates performance of new proposed priority PAUSE, which includes two new flexible programmable fields (predetermined pause time and priority) in order to provide granular flow control. The proposed PPFC is fair in the sense that it distributes the resources among the flows based on their priorities during congestion. Moreover it reduces the amount of buffer overflow and packet loss and it would provide an efficient use of link bandwidth with high throughput. In addition, priority PAUSE enables optimal bandwidth management of virtual channel for different IPv6 traffic priorities and it enhances the QoS in Metro Ethernet.