The IESG has approved the following document: - 'Diameter Applications Design Guidelines' (draft-ietf-dime-app-design-guide-28.txt) as Best Current Practice This document is the product of the Diameter Maintenance and Extensions Working Group. The IESG contact persons are Benoit Claise and Joel Jaeggli. A URL of this Internet Draft is: http://datatracker.ietf.org/doc/draft-ietf-dime-app-design-guide/ Technical Summary The Diameter Base protocol provides an extensibility mechanism enabling a consistent way to define new Diameter applications, commands and attribute- value-pairs or modify existing ones. This document is a companion document to the Diameter Base protocol that further clarifies the rules to extend Diameter. This document is a guidelines document and therefore informative in nature. Working Group Summary The working group reached consensus on the document and the contents of the document was discussed in length. Document Quality The document is a guideline document as such. Several topics discusses in the document originate from specification and implementation experience done outside IETF, specifically in 3GPP, when implementing and deploying new Diameter applications. The document has received early reviews from the AAA-Doctors, OPS-DIR, SecDir and Gen-Art. The request for reviews was posted into dir-coord and aaa-doctors mailing lists. Received comments have been reflected. Since the document does not define any MIBs, media types and such. Therefore, there is no need for MIB Doctor or Media Type and such expert reviews. Personnel Jouni Korhonen (jouni.nospam@gmail.com) is the document shepherd. Benoit Claise (bclaise@cisco.com) is the responsible Area Director.