| The Internet Protocol (IP) provides best effort delivery of IP datagrams i.e. network resources are contended and fairly shared by all traffic injected into the network. The IP does not provide any means for end to end flow control. Since the traffic demands are stochastic and cannot be predicted, congestion is unavoidable on EP Networks. EP Network's performance degrades considerably when congestion happens. Once the capacity of the network is exceeded, all users experience delays, not just the user creating the additional traffic. In recent years, enhanced network QoS service architectures such as IntServ and DiffServ have been defined to address these issues. Although such enhanced services are valuable and indeed in need, these services requires that certain amount of network resources have to be reserved.; The proposed Soft Available Bit Rate (SABR) service presented in this paper, relaxes the hard ATM ABR service constraints and at the same time attempts to preserve the existing best-effort paradigm of the EP Network. This new service guarantees that if a certain amount of the network bandwidth is made available to SABR users, those users share the bandwidth co-operatively by adapting the traffic rates as per the congestion status of the network. |
