Roaming services allow users that have a contract with a voice service provider to use access resources owned by other providers known as internet access providers. This draft proposes a tokenbased Authentication, Authorization, Accounting (AAA) and billing model for roaming users. It also introduces a protocol solution for the proposed model that is based on the Assertion Markup Language (SAML...

The 3rd Generation Partnership Project (3GPP) will use the Session Initiation Protocol (SIP) as a session signalling protocol in the IP Multimedia Subsystem (IMS) of next generation UMTS systems. Certain nodes on the signalling layer have to process a large number of SIP messages. This paper introduces a concept for efficient SIP message routing and user assignment. The SIP Message Overflow Rou...

In this paper we perform an analysis of SIP, a popular Voice over IP (VoIP) protocol and propose a framework for capturing and analyzing volatile VoIP data in order to determine forensic readiness requirements for effectively identifying an attacker. The analysis was performed on real attack data and the findings were encouraging. It seems that if appropriate forensic readiness processes and co...

The Message Session Relay Protocol draft-ietf-simple-message-sessions-07.txt Status of this Memo By submitting this Internet-Draft, I certify that any applicable patent or other IPR claims of which I am aware have been disclosed, and any of which I become aware will be disclosed, in accordance with RFC 3668. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), it...

There are currently two standards for signaling and control of Internet telephone calls, namely ITU-T Recommendation H.323 and the IETF Session Initiation Protocol (SIP). We describe how a signaling gateway can allow SIP user agents to call H.323 terminals and vice versa. Our solution addresses user registration, call sequence mapping and session description. We also describe and compare variou...

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...

In recent years, Web services have been drawing more attention to the computer industry. They are built on open standards and provide solutions for integrating applications across enterprises. The technologies behind Web services are Universal Description, Discovery and Integration (UDDI), Web Services Description Language (WSDL) and Simple Object Access Protocol (SOAP). SOAP, which is responsi...

This document defines and registers with IANA the new "fax" media feature tag for use with the Session Initiation Protocol (SIP). Currently, fax calls are indistinguishable from voice calls at call initiation. Consequently, fax calls can be routed to SIP user agents that are not fax capable. A "fax" media feature tag implemented in conjunction with caller preferences allows for more accurate fa...

Because of the emergence of heterogeneous access devices and diverse wired and wireless networks, and a substantial lack of support for integrating these networks, we are building a communication network and a service infrastructure that provides integrated telephony and data services across these networks. We generalize the basic call service to support communication between two or more call p...

Many multimedia conference initiation and control protocols like the Session Invitation Protocol or ITU-T H.323 are likely to coexist on the Internet. Although these protocols have di erent invitation schemes and di erent addressing mechanisms, they all need transport addresses to send conference calls. Considering users mobility, address redirection mechanisms were built into invitation protoc...