ملخص: This paper focuses on the optional dynamic bandwidth allocation (ODBA) scheme to support video-on-demand (VoD) services in virtual private networks (VPN). Firstly, an approach based on playback tunnel is proposed to determine a feasible range of bandwidth used for dynamic bandwidth allocation to transport video segments with the guarantee that the playback buffer neither underflows nor overflows. Secondly, optional DBA schemes including left-edge DBA, right-edge DBA, middle-tunnel DBA (MT-DBA) and reduced-bandwidth-variability DBA (RBV-DBA) are investigated extensively. The proposed schemes are evaluated by a set of real-life MPEG video traces. The obtained results show that the RBV-DBA scheme outperforms other schemes in terms of reducing peak rate, traffic burstiness and bandwidth variability. On the other hand, the MT-DBA scheme can effectively avoid the playback buffer overflow and underflow

لغة: إنجليزية