Firewall Traversal in the Grid Architecture

Computational grids have been at the forefront of e-science supercomputing for several years now. Many issues have been settled over the years, but some may only appear to be so. One of these issues is firewall traversal. Many solutions have been proposed and developed. We have developed two such solutions ourselves: Remus and Romulus, but like all other solutions, they are limited in application. Others are working on proposed standards or solutions based on existing Internet standards and RFCs. However, we still have production-level grids that instead operate their grid resources on an open firewall policy. Some propose moving grids on top of peer-topeer networks and/or overlay networks, or rebuilding grids on top of clouds instead. Existing grid infrastructures have not rushed to follow either path, however, as the required changes will take considerable effort and cost for currently running systems. This paper investigates the problem and offers a different proposal: a minor revision to the grid architecture. In order to support what we propose, we will look at several proposed solutions and identify their limitations. We also classify them into two distinct approaches, and discuss how each one is not by itself sufficient for all situations. Then we shall show that a slight improvement to the grid protocol architecture provides a multi-pronged architectural solution.