University of Helsinki

Latest Content From University of Helsinki

Whitepaper: Model Driven Architecture For Telecommunication Services

by University of HelsinkiJan 01, 2008

Different middleware platforms are widely used in developing telecommunication services. The interoperability between different middleware platform and between parts of applications running on the different middleware platforms becomes even more important than ever before. The MDA is a new way of writing specifications and developing applications, based on a platform-independent model (PIM). It has been considered as a potential approach for solving the interoperability issue in the telecommunication domain. This paper tackles several aspects of applying MDA in this domain.

Whitepaper: Responding to Spurious Timeouts in TCP

by University of HelsinkiJan 01, 2008

Spurious TCP timeouts cause unnecessary retransmissions and congestion control back-off. The Eifel algorithm detects spurious TCP timeouts and recovers by restoring the connection state saved before the timeout. This research paper presents an enhanced version of the Eifel response to spurious timeouts and illustrates its performance benefits on paths with a high delay-bandwidth product. The refinements concern the following issues an efficient operation in presence of packet losses, appropriate restoration of congestion control and adapting the retransmit timer to avoid further spurious timeouts.