We make a billing system which has a JSON API which allows our customers to hook in FreeRADIUS servers to provide RADIUS and DHCP. Up to now we have always used rlm_perl along with a perl script using the JSON and HTTP perl modules to generate the JSON and get it to and from our API. Recently, I have done a few experiments using the rlm_rest module in place of rlm_perl, and I have been very impressed. It is easy to configure and it provides a simpler solution for us, in that it renders the perl script unnecessary. I would like to ask whether there is likely to be any performance difference beteween these two solutions. rlm_perl is performing well for us and as I understand it runs in a multithreaded mode whereby multple perl instances can be created by multiple server threads. I would like to ask whether the rlm_rest module is likely to offer as good as or better performance as we are currently getting with rlm_perl. Also, I would like to understand whether it is necessary to configure multiple instances of rlm_rest and put them for example in a load_balance section in order to get the best performance. Ben Thompson