Method and apparatus for quality of service determination

Abstract

A method of estimating bandwidth capacity, available bandwidth and utilization along a path in an IP network is disclosed. ICMP time-stamp requests are sent from a source host on the edge or inside the network to all routers on the end-to-end path to a desired destination. Differences between time-stamp values are used as indicators of QoS service at each router. The collected measurements are then processed at the sending host to infer QoS parameters in terms of path capacity in bit/sec, available bandwidth in bits/sec, individual link utilization and congestion at each router. These parameters can be combined to infer the QoS service in terms of bandwidth on the end-to-end path.

1 . A method comprising:
 probing an end-to-end path to identify capacity of routers on the end-to-end path;   transmitting a ping request to a hop on the path;   receiving a ping reply; and   processing the ping reply to generate a quality of service (QoS) estimate.   
   
   
       2 . The method defined in  claim 1  wherein the hop comprises a hop on an IEEE 802.11 wireless local area network (LAN). 
   
   
       3 . The method of  claim 1 , wherein time intervals between the ping requests vary according to a packet loss model. 
   
   
       4 . An article of manufacture having one or more recordable media storing instructions thereon which, when executed by a system, cause the system to:
 probe an end-to-end path to identify capacity of routers on the end-to-end path;   transmit a ping request to a hop on the path;   receive a ping reply; and   process the ping reply to generate a quality of service (QoS) estimate.