Implementation Issues to Provide the GFR Service Guarantees to TCP / IP Traffic

The performance of various GFR (Guaranteed Frame Rate) implementations has been recently studied due to the interest to provide bandwidth guarantees with a simpler implementation than ABR in ATM networks. In this paper we describe and evaluate a scheduling algorithm to provide the GFR service guarantees. The evaluation is performed by simulation using TCP connections. The proposed scheduling is compared with the Weighted Fair Queuing implementation. We study in detail the problem of providing minimum cell rate guarantees in case of cell loses with both implementations and show a possible solution which requires modifying both the TCP flow control mechanism and the buffer management.