IEEE LTSA framework for e-Learning provides a template that may be used for digital distance learning. However, with the advent of newer and faster communication technologies, the concept of on-line learning and evaluation came into being. Most of these systems are operating in an environment of distributed system. On-line learning expanded the earlier computer-aided, computer based and other e-Learning methodologies, but remained confined to predefined need. Dynamic or on-the-fly customization of different learning services was not possible due to the lack of suitable software architecture. Introduction of Service Oriented Architecture (SOA) proves to be a boon for any web portal based interactive customized application. IEEE LTSA model specifies a high-level architecture for information technology supported learning, education and training systems. It describes high-level system design in an integrated environment. Independent modules may be considered as stand-alone services but interconnected modules may or may not be converted successfully into composite services. This paper presents a step-wise extension of IEEE LTSA e-Learning architecture to a secure Client-Server based model and then to a Distributed System based model with added security features. An extended e-Learning architecture in SOA is proposed, which is capable of providing secured stand alone as well as composite teaching-learning services. The proposed architecture is then tested with a case study of a e-Learning web portal to prove the validity of the proposed extended architecture, which shows enhancement over the present architecture used. It also brings out the viability of e-Learning services in SOA.