 
                    | Contact: | www | | 
| Office: Phone: Fax: Admin: | GHC 9109 (412) 268-3064 (412) 268-5576 Gates-Hillman 9215 (412) 268-5099 | 
| Mailing Address: | School of Computer Science Carnegie Mellon University 5000 Forbes Avenue Pittsburgh, PA 15213-3891 | 
| Position: Projects: | Professor, CSD FAWN | 
My research focuses on networks and distributed systems, with an eye 
                        
                        towards improving the availability and performance of Internet-based 
                        
                        systems.  My previous research includes the development of overlay 
                        
                        networks to route around Internet failures, work on secure operating 
                        
                        systems and storage systems, and Internet measurement. 
                        
                        Highly Available Internet Architecture
                        This project is examining new architectural concepts to improve the 
                        
                        availability and security of the Internet, without compromising 
                        
                        the fundamental flexibility that underlies its success.  The 
                        
                        primitives we are currently exploring include enhancing end-hosts' 
                        
                        ability to select between paths through the Internet, and permitting 
                        
                        hosts or networks greater control over what traffic they receive, in a 
                        
                        way that is enforceable deep inside the network.  This project 
                        
                        emphasizes real-world measurements from our own Internet testbed as 
                        
                        well as public testbeds such as Planetlab to understand the problems  facing 
                        
                        today's network, and to evaluate potential solutions. 
                        
                        The Data-Oriented Transfer project, in collaboration with 
                        
                        researchers at Intel Research, is examining a new way to structure 
                        
                        Internet applications that perform bulk transfers.  Instead of 
                        
                        performing the transfers themselves, these applications pass their 
                        
                        data to a transfer service that performs the transfer on their 
                        
                        behalf.  The transfer service serves as a locus for the development 
                        
                        and deployment of novel transfer techniques.  Our initial efforts 
                        
                        include merging e-mail delivery with peer to peer techniques (e.g., 
                        
                        using peer to peer to collaboratively deliver large file attachments 
                        
                        to multiple receivers), and developing transfer techniques to improve 
                        
                        the performance of applications when the underlying network layers 
                        
                        perform poorly. 
                        
                        Opportunistic Resource Use in Wireless Networks
                        is examining better ways to make use of 
                        
                        wireless networks by explicitly exploiting concurrent multi-path 
                        
                        transfers, by opportunistically caching overheard traffic, and by 
                        
                        taking advantage of quiescent periods to preemptively transfer data 
                        
                        across the network.  This project is attempting to turn one of 
                        
                        wireless networks weaknesses—a shared broadcast medium—Into a 
                        
                        strength, by taking advantage of the 
                        
                        processing and storage power available at nodes to avoid expensive 
                        
                        wireless communication.