In the session initiation protocol (SIP), payments have been proposed as a way for vendors to obtain profit from the services they provide. Payments in SIP have also been proposed for microbilling and even as a solution to SPAM in VoIP systems. Although several proposals exist for making payments in SIP, they present some limitations when we want to pay for access to real-time services: either ...

This document explores an ambiguity in the interpretation of the element of the Presence Information Data Format for Location Objects (PIDF-LO) in cases where PIDF-LO is conveyed by the Session Initiation Protocol (SIP). It provides recommendations for how the SIP location conveyance mechanism should adapt to this ambiguity. Documents standardizing the SIP location conv...

The Session Initiation Protocol (SIP) is commonly used to establish Voice over IP (VoIP) calls. Mostly recently, Yoon et al. proposed a new secure and efficient SIP authentication scheme in a converged VoIP network based on ECC. In this paper, we first demonstrate that the recently proposed SIP authentication scheme is insecure against off-line password guessing attacks. Thereafter, we propose ...

Es wird eine Vorgehensmethodik für eine strategische Informatikplanung (SIP) beschrieben, die in der Schweiz von der Bundesverwaltung als Grundlage für die strategische Informatikplanung in allen Departementen und Verwaltungseinheiten vorgegeben ist [SIP-Bund 2003]. Die betrachtete Methode orientiert sich im Wesentlichen an folgenden Grundsätzen: ❏ Informatik ist ein Werkzeug von strategischer ...

The steady improvements in the networking infrastructure and ever increasing broadband penetration has fueled the resurgence of voice-over-IP (VoIP). One of the important contributors to this growth has also been the development and wide acceptance of the session initiation protocol (SIP). However, the current usage of SIP requires a per-application deployment (each application using its own SI...

The popularity of gateways that interwork between the PSTN (Public Switched Telephone Network) and SIP networks has motivated the publication of a set of common practices that can assure consistent behavior across implementations. This document taxonomizes the uses of PSTN-SIP gateways, provides uses cases, and identifies mechanisms necessary for interworking. The mechanisms detail how SIP prov...

The objectives of this study were to investigate the immune enhancement activity of the Sarcodon imbricatus polysaccharide (SIP). In this study, water extraction method was employed to isolate polysaccharides from the Sarcodon imbricatus. The immunoloregulation effects of SIP were evaluated with models of cyclophosphamideinduced mouse immunosuppression. The immunoloregulation activities of SIP ...

Session Initiation Protocol (SIP) was standardized for real-time applications and extended to support terminal mobility by Internet Expert Task Force (IETF). However, SIP terminal mobility suffers from the considerable handoff latency which is unsuitable for the real-time communications. In this paper, we propose Predictive Address Reservation with SIP (PAR-SIP) which decreases handoff delay by...