Manjur S. Kolhar

Multimedia Communication: RSW Control Protocol and IAX

Multimedia communication has become basic necessity of internet users. It has become more and more relevant in distributed environments. There are many protocols available in IP telecommunication world for signaling and control of Internet telephone calls. InterAsterisk eXchange protocol and RSW are considered to be major protocols for signaling and data. These two protocols provide competitive voice and video functionality using different mechanisms and provide similar quality of service. Both protocols have been in use in very big way. This paper surveys protocol functions and mechanism for media transmission and signaling of these two protocols. This paper intended to introduce possibility of bringing together.

Delta-Multiplexing: A Novel Technique to Improve VoIP Bandwidth Utilization between VoIP Gateways

Gradually, Voice over Internet Protocol (VoIP) has been dominating the telecommunications world. Unfortunately, its applications are injecting a huge number of small packets in the network, which produces high overhead and therefore wastes network bandwidth. This paper proposed the use of a novel multiplexing technique, Delta-Multiplexing, to save the wasted bandwidth. In the Delta-Multiplexing technique, the VoIP packets destined to the same destination gateway are aggregated in a single UDP/IP header, therefore reducing the header overhead and saving network bandwidth. Moreover, the Delta-Multiplexing technique reduces the size of the packets payload by transmitting the difference between the consecutive packets payloads. Accordingly, the Delta-Multiplexing technique greatly saves bandwidth. We have simulated the Delta-Multiplexing technique using a 14-byte LPC codec. The result showed that Delta-Multiplexing is capable of saving between 68% and 72% as compared to conventional techniques (without multiplexing). Moreover, the Delta-Multiplexing technique reduces the number of VoIP packets running over the network, therefore reducing network traffic, overload, and congestion, thus improving the overall network performance.

MuxComp - A New Architecture to Improve VoIP Bandwidth Utilization

Voice over IP (VoIP) is expected to be the key of the communication industry in near future. Inefficient bandwidth usage by VoIP consumed the network bandwidth. The problem of inefficient bandwidth usage is handled by several techniques such as silence suppression, packets multiplexing, and voice compression. This work proposed new architecture to save network bandwidth for VoIP. We called the new architecture MuxComp. MuxComp, combines packets multiplexing and voice compression. Whereas, multiplexing the voice packets reduce the overheads, furthermore give the opportunity to compress the packets again. The MuxComp architecture consists of two entities. The MuxCmp entity is VoIP gateway in the sender side, which performs the multiplexing and compression processes to the packets and sends them to their destinations. The DCmpDMux entity is VoIP gateway in the receiver side, which performs the reverse processes of MuxCmp through de-compression and de-multiplexing the packets. Furthermore, this work is considered the size of the multiplexed packets, whereas the size must not exceed the network Maximum Transfer Unit (MTU), therefore avoiding the fragmentation delay through the network.

Storage allocation scheme for virtual instances of cloud computing

Cloud computing delivers resources and services through virtual machines on a pay-as-you-go basis. The allocation of storage space to users is usually determined by means of open allocation mechanisms that cannot guarantee an efficient allocation. Current allocation mechanisms do not consider user requests when making provisioning decisions. In other words, they assume that the storage spaces are fixed. In this study, we propose an algorithm for allocating storage spaces based on the requests of users. We present a unified storage allocation scheme (USAS) for cloud computing. USAS is a dynamic storage allocation framework for unlimited, limited, and free users. Our proposed approach is based on a storage partitioning policy, and we have compared our proposed scheme with open storage scheme and fixed storage scheme with common partition. We show through simulation study that USAS dynamically allocates space for different user requirements for all traffic loads.