Hazem El-Gendy

Towards sound development of PIXITP, conformance test suites, and conforming implementations for various Formal Description Techniques

The testability of a protocol standard is a property of the standard that reflects the degree of precision in developing universal interpretation of what it means for an implementation to conform to the standard, and the ability to exercise the implementations of the protocol standard for purposes of assessing their conformance to the standard (Hazem El-Ghendy, et al., November 20-23, 1995). In this paper, we investigate the Conformance Testing Requirements (CTRs) of a protocol standard that result from the formal specification of the allowed (dynamic) behavior of the protocol standard. We focus on those CTRs that are applicable to all the international formal description techniques (FDTs); more specifically, SDL, Lotos, Estelle, and ASN.l. We develop a distinction among Implemenlorpsilas options, Implementerpsilas Choice, and Non-Deterministic Choices as well as testing semantics for each of them. Then, we develop rules for the explicit and precise specification of these CTRs, and for developing a precise and explicit P1X1TP (protocol implementation extra information for testing proforma). These rules are essential for facilitating the controllability and propagation of observability; consequently, enhancing the testability of the protocol standard.

Towards ISO interface protocol for interactive multimedia intelligent terminals

A multimedia-“ISO-Application Layer” Interface for interactions, via services called Input/Output Services, between desktop applications and voice terminals is presented in this paper. Input/Output services allow computer applications to provide users with enhanced services by exploitation of the characteristics of a variety of telephony device types. This is by interacting with a switch-based software object, called Information-Path, associated with the device that allows input to be received from the device and output to be sent to the device. A Standard specification for such an interface may be developed by ANSI (American National Standards Institute) Tl Committee, ECMA (European Computer Manufacturers Association) TC32-TG11, or ITU/TSS (formerly CCITT) IN (Intelligent Networks) Group.

Formal development of universal protocol implementations conformance statement proforma

In this paper, we examine the adequacy of the current international protocols implementation conformance statement proforma (PICSP) to meet the end users conformance testing requirements (CTRs). We focus on those CTRs that are applicable to the international formal description techniques (FDTs). A number of shortfalls are uncovered. Then, we develop refinements called testability-directed PICSP (TDPICSP), of the current international PICSP to rectify the shortfalls. It also enhances the testability of the protocol standard. We illustrate our development by examples using international standards.

Applying open networks communication authentication

Information exchanged over open networks in many cases contain sensitive data, accordingly, security became an important issue to many people. Authentication has proven to be a deterrent to intruders and ensures that information is transmitted from trusted senders to a trusted receiver. This work is an extension of previous authentication work. It presents a scrambling and encrypting mechanism to authenticate information in packet headers of the data link layer, HDLC — PPP protocol. HDLC was selected for many reasons one of which is being secured by nature.

Complete management scheme for intelligent terminals for the information super-highways and its design

An Intelligent Network (IN) is a general concept network command architecture to enable the rapid introduction of new services by rearranging the basic functions of transport information mainly (voice, data, and images). Modern telecommunication networks are complex distributed systems that require high monitoring level using specific management network tools. An IN management scheme for ISO Interface is presented in this paper. The interface ensures different interactions through a set of services called Input/Output Services between desktop applications and voice terminals. Such services are designed in order to allow computer applications to provide users with enhanced features tacking advantages from the wide variety of telephony device characteristics and types. Basically, we suggest a software switch-based interaction scheme. The switch-based software object called Information-Path, is associated with the device that allows input to be received from the device and output to be sent to the device. The management scheme is suitable for multimedia interactive telecommunications. It covers applications that involve only voice calls (Integrated Services Digital Network (ISDN) B channel), only data calls (ISDN D channel), or both voice calls and data calls (both ISDN B channel and ISDN D channel). This makes the proposed system suitable for multimedia communications that involve voice, data and graphics. The feasibility and applicability of our proposal is demonstrated through a set of applications scenarios that involve multimedia mails exchanges.

Management scheme for intelligent terminals for the information super-highways

An IN (Intelligent Networks) management scheme for ISO Interface is presented in this paper. The interface is for interactions, via services called Input/Output Services, between desktop applications and voice terminals. These services allow computer applications to provide users with enhanced services by exploitation of the characteristics of a variety of telephony device types. This is by interacting with a switch-based software object, called Information-Path, associated with the device that allows input to be received from the device and output to be sent to the device. The management scheme is suitable for multimedia interactive telecommunications. It covers applications that involve only voice calls (ISDN B channel), only data calls (ISDN D channel), and both voice calls and data calls (both ISDN B channel and ISDN D channel). So, it is suitable for multimedia communications that involve voice, data, and graphics. The applicability is demonstrated by applications scenarios that involve multimedia mail.

Towards modeling of communications protocols

In this paper, we develop a testability-directed model of a communications protocol. This modeling has applicability in different phases of development of sound advanced telecommunications systems such as universal personal communications systems. The model is called Testability-Directed Standard of a communications Protocol (TDSP). We provide reasoning and justification for every component of TDSP. A TDSP precisely specifies the rules of interactions among the communicating entities and explicitly and precisely specifies the conformance testing requirements.

Formal automated transformation of SDL specifications to Lotos specifications

In this paper, a formal method for automated transformation of an SDL specification into a corresponding Lotos specification is presented. The method is applicable to various SDL specifications and to various communications protocols for various ISO (International Standards Organization) OSI (Open Systems Interconnections) layers. This formal automated transformation facilitates immediate indirect applicability of future formal methods for derivation of testing sequences for Lotos specifications to SDL specifications. Firstly, the formal automated transformation method is applied to generate a Lotos version. Then, the Lotos-based derivation method is applied. This facilitates the best coverage of the testing sequences for SDL specifications as the formal test derivation method with the best coverage can be applied. This also facilitates comparison of various test derivation methods in terms of coverage. We develop an algorithm for constructing the Lotos specifications.