Connectivity to small and medium-sized companies that cannot afford, or lack the skills, to operate an AS2 messaging gateway server successfully, remains a challenge for many companies.  Recently, the new AS4 B2B protocol was developed.  It has all the functionality that AS2 offers today, but also provides better support for SMEs and is based on more modern Web Services technology. The GS1 eCom Technology Group and OASIS Members have created and published a white paper to explain the rationale for AS4, both from a business and an information technology point of view, and its relevance to the GS1 community. It explains how AS4 relates to previous work on e-business protocols in ebXML and within OASIS. The paper also explains AS4 in some details and shows the similarities, differences and added value of AS4 compared to both AS2 and to other Web Services profiles. The paper concludes with a discussion on current status, positioning and deployment options for AS4.