A strategy to interconnect multimedia LANs to an ATM network | |
| Author | Krishna, Rao P. |
| Call Number | AIT Thesis no. TC-96-2 |
| Subject(s) | Asynchronous transfer mode Local area networks (Computer networks) |
| Note | A thesis submitted in partial fulfillment of the requirement for the degree of Master of Engineering, School of Engineering and Technology |
| Publisher | Asian Institute of Technology |
| Abstract | Providing connectionless traffic support in a legacy LAN to ATM interconnection has been a prime topic for research in recent times. The LAN connectionless protocol being random access technique and as no traffic parameters are supplied by LAN source nodes, the LAN-ATM Interworking Unit's (IWU) job of bandwidth allocation becomes extremely difficult. The 'Bandwidth advertisement scheme" proposed in [GERLA et. al., 1993] solves the problem of how much bandwidth to allocate. But, it mainly focuses on ATM performance assuming that only data applications are present on LANs hence, no attempt is made to improve LAN performance. It could also suffer from congestion at IWU as there is no control on the incoming traffic at IWU. With present boom in multimedia services it is inevitable that LANs will increasingly have real-time applications running on them. Under high traffic conditions LAN performance suffers from increased delays and added to this a congestion at IWU could severely affect the end-to-end realtime service delay. To solve these problems, a new strategy is proposed which is an extension of the bandwidth advertisement scheme. In the proposed scheme, the IWU congestion problem is solved by rejected new services under high traffic conditions (i.e., when incoming traffic at IWU is comparable to the outgoing ATM trunk capacity) thus, attempting to reduce delays at IWU as well as on LAN. This would also reduce queue size at IWU resulting in minimal packet loss at IWU. Further, the bandwidth allocation is based on traffic measurements at the IWU. As we are considering multimedia applications, the bandwidth requirements for different services are different. Hence, a traffic table containing three parameters corresponding to the bit rates of the three services is maintained in IWU. The initial bandwidth allocation for new services is carried out with the information from this traffic table. The proposed strategy is evaluated and compared with bandwidth advertisement scheme using simulation. The results of simulation show an improvement in LAN utilization, lower delay on LAN as well as in IWU and congestion at IWU is reduced. |
| Year | 1996 |
| Type | Thesis |
| School | School of Engineering and Technology (SET) |
| Department | Department of Information and Communications Technologies (DICT) |
| Academic Program/FoS | Telecommunications (TC) |
| Chairperson(s) | Chindakorn Tuchinda |
| Examination Committee(s) | Erke, Tapio;Zhang, Jian-Guo |
| Scholarship Donor(s) | Asian Institute of Technology Partial Scholarship |
| Degree | Thesis (M.Eng.) - Asian Institute of Technology, 1996 |