A Survey of Bandwidth Optimization Techniques and Patterns in VoIP Services and Applications

This article surveys the various techniques adopted for optimising bandwidth for VoIP services over the period 1999-2014. The improvement of bandwidth can be realized through; silence suppression measure of repressing the silent portions (packets) in a voice conversation using Voice Activity Detection algorithm; by so doing, the transmission rate during the inactive periods of speech is reduced, and thus, the mean transmission rate can be reduced. A second measure is packet header reduction which defines a process of multiplexing and de-multiplexing packet headers to curb excesses. Voice/ Packet Header compression is considered the most productive of all the techniques, offering a scheme where VoIP packets are compressed from the 40 bytes of size to a smaller byte size of 2 bytes. When combined with aggregation, compression potentially yields a compressed size of up to 1 byte. In either case, bandwidth save is reached using compression and decompression codecs of varying data and bit rates. It is envisaged that an improvement in the performance of codecs would yield a better result in terms of enhancing results favourably in Voice over broadband networksComment: 8 pages, 7 figures. ISSN (Print): 1694-0814 | ISSN (Online): 1694-078

Enhancing Throughput Efficiency via Multiplexing and Header Compression over LISP Tunnels

Abstract — This article explores the possibility of using traffic optimization techniques within the context of the LISP (Locator/ Identifier Separation Protocol) framework. These techniques use Tunneling, Multiplexing and header Compression of Traffic Flows (TCMTF) in order to save bandwidth and to reduce the amount of packets per time unit. Taking into account that encapsulation is necessary in LISP, bandwidth can be drastically reduced in flows using small packets, which are typical of many real-time services. The ability of the LISP framework to manage the signaling of TCMTF options is also studied. An analytical expression of the savings, as a function of the different header sizes, is devised and used to calculate the maximum expected savings. Different services and scenarios of interest are identified, and this allows the consideration of tests with real traffic traces, showing the savings as a function of the multiplexing period, and demonstrating that the additional delays can be acceptable for real-time services. Keywords-LISP; multiplexing; header compression; real-time I