dnssdext draft charter:

Description: 
Currently, zeroconf networking protocols are generally used to discover services within the scope of a single link. In particular, the Bonjour protocols suite, comprising mDNS (RFC 6762) and DNS-SD (RFC 6763), are widely used for discovery and resolution of services and names on a single link.

The Bonjour protocol suite is commonly used in many scenarios, including home networks, commercial and campus enterprise networks, and may be of use in certain mesh networks. However, the multicast Bonjour protocols are constrained to link-local scope, so can only be used to discover services on the same link. In a typical current home network, which is a single link, users should experience the desired discovery behavior. However, in future multi-link home networks (as envisaged by the homenet WG) and in routed campus or enterprise networks, devices and thus users can only discover services on the same link, which is a significant limitation. Such limitations have led to calls, such as those by the Educause petition, to develop an appropriate solution to span multiple links, or to perform discovery across a wide area (not necessarily on directly connected links).

In addition, the ZigBee Alliance Smart Energy Profile 2.0 commercial standard currently under development has specified the Bonjour protocols as its method of zero configuration discovery. However, its use of wireless mesh multi-link subnets and its use across traditional routed networks will require extensions to the Bonjour protocols to allow operation across multiple links.

As demand for service discovery across wider area routed networks grows, some vendors are beginning to ship their own early solutions. It is thus both timely and important that efforts to develop improved, scalable, autonomous service discovery solutions for routed networks are coordinated towards producing a single, standards- based solution.

Goals: To that end, the primary goals of the dnssdext WG are as follows:

1. To document a set of requirements for scalable DNS-based service discovery in routed, multi-link networks in the following four scenarios:
a) Commercial enterprise networks
b) Academic/educational/university campus networks
c) Multi-link home networks, such as those envisaged by the HOMENET WG
d) Multi-link/single subnet (mesh) networks, such as those described by the ZigBee Alliance Z-IP specification

2. To develop an improved, scalable solution for wide-area service discovery that can operate in multi-link networks, applicable to the scenarios above.

3. To develop a BCP for the coexistence of zeroconf (mDNS) and unicast (global DNS) name services in such multi-link networks, which should include consideration of both the name resolution mechanism and the namespace.

It is important that the dnssdext WG takes input from stakeholders in the scenarios it is considering. For example, the homenet WG is currently evaluating its own requirements for naming and service discovery; it is up to the homenet WG as to whether it wishes to recommend adoption of the solution developed in the mdsnext WG, and thus coordination between the WGs is desirable.

Deliverables: 
The WG will produce three documents: an Informational RFC on the requirements for wide-area service discovery protocols; a Standards Track RFC documenting a wide-area service discovery solution that is applicable to those scenarios; and a BCP document describing the most effective method to integrate mDNS and global DNS name services.

Milestones:
Sep 2013 Formation of the WG
Oct 2013 Adopt requirements draft as WG document
Nov 2013 Submit requirements draft to the IESG as an Informational RFC
Mar 2014 Adopt wide-area service discovery solution draft as WG document 
Mar 2014 Adopt zeroconf and unicast DNS integration BCP draft as WG document 
Sep 2014 Submit wide-area service discovery solution draft to the IESG as Standards Track RFC 
Sep 2014 Submit zeroconf and unicast DNS integration solution draft to the IESG as BCP