Due to a domain/registrar problem, the onsip.org domain used in referencing a server with SER Getting Started, module docs, etc has caused broken links on iptel.org the last week or so. The plan is to move everything over to iptel.org servers/domain, but I haven't had time yet. I have now updated the referenced links on iptel.org site to use a temporary domain name, so everything should be ok now.
Please raise your voice if there are still onsip.org reference lying around on iptel.org. g-)