Re: [Fwd: local device discovery - api, demo and source code]

If WebSocket were extended to permit send/recv of a UDP multicast/unicast
packet, then it should be possible to implement all of UPnP protocol,
including SSDP, directly in client side JS via an (extended) WebSocket
enabled UA.

The question remains whether it is necessary or useful to define higher
level abstraction layers, e.g., a low-level, generic UPnP layer, UPnP
service specific layers, etc.


On Fri, Apr 15, 2011 at 4:46 PM, Dave Raggett <> wrote:

> On Thu, 2011-04-14 at 11:33 -0700, Mark Watson wrote:
> > Hi Dave,
> >
> >
> > Very interesting!
> >
> >
> > The flipside of discovery is advertisement. Are there any plans for a
> > similar Javascript API for web applications to advertise themselves so
> > that they can be found ?
> Yes, indeed, along with the means to establish peer to peer connections
> between browsers. This raises the question of how web applications
> describe themselves for the purposes of being discovered. Personally, I
> like the approach taken by multicast DNS**, where users can name
> services, and can describe them with a short list of name value pairs.
> However, I would be interested in hearing your views.
> The code I used for SSDP for UPnP suggests that it would be very easy to
> enable browsers to listen for multicast and unicast datagram messages
> carrying JSON events, and likewise to be able to send such messages.
> This would be handy for applications where browsers form an ad hoc
> group, e.g. for multi-user games.
> For P2P connections across firewalls and well behaved NAT boundaries,
> the idea is to use agents on Internet servers to assist with
> establishing the connections. A "personal zone" is established that
> includes all of your devices and cloud based services, and which
> supports the notion of social proximity for establishing connections
> between your devices and your friend's devices.
> ** multicast DNS is also very well designed for fast responses.
> --
>  Dave Raggett <>

Received on Friday, 15 April 2011 09:10:18 UTC