Group communication provides one-to-many communication primitives that simplify the development of highly available services. Despite advances in research and numerous prototypes, group communication stays confined to small niches. To facilitate the acceptance of group communication by a larger community, a new specification and API, called JMSGroups, based on the popular Java Message Service (JMS) has previously been presented. As a follow-up, this paper focuses on the architectural issues of the JMSGroups implementation. We consider an implementation based on a JMS server, i.e., a JMS server that is modified internally to provide a group communication service. Usually JMS server is implemented as a single entity providing its service to numerous clients. However, single server architecture is exposed to failures and is not suitable for group communication. To address this problem, we discuss the issues related to the JMS server replication (first without providing group communication). Different replicated architecture options are presented and compared. Finally, we show how to construct a fault-tolerant JMSGroups system, by extending the replicated JMS server with a group communication service.