Room Discovery Protocol within the Naim app

Posted by: Revoliño on 15 June 2018

Could someone tell me which network protocols are used for Room Discovery within the Naim app?

Yesterday I've changed my network from one subnet to multiple subnets, my Naim NAC-N 272 now separated from my wireless devices. After the change, my 272 cannot be found automatically any more. What does work is manually add the 272 to the app.

But of course I want to know why it's not working any more and thus I need to know which protocol is used for this discovery process.

Thanks!

Posted on: 15 June 2018 by Simon-in-Suffolk

The main discovery protocol used by UPnP and the Naim application is SSDP using multicast group IP address 239.255.255.250.

You should understand that UPnP as with many other similar protocols are designed to work within a single layer 2 subnet for simplicity and ease of setup in typically consumer setups... therefore by creating multiple subjects that you are having to route between, you will need to specify PIM on your router (assuming its a commercial grade product like a Cisco router that supports it) for SSDP and any other multicast app to work. You can probably set in Sparse or Dense mode - might need to experiment. However this added complexity I wouldn't recommend unless you are totally comfortable with it and there is a good reason to use separate subnets for your UPnP domain - and you may need other forwarders setup as well.

The best approach I suggest is to keep your UPnP domain within its own subnet which is the typical home network setup

Posted on: 15 June 2018 by Revoliño

Thank you Simon-in-Suffolk!

I was already experimenting with the different PIM configurations on my ASA 5505 but I’m not yet successful. A lot of people are suggesting SSDP doesn’t go intra-interface on the 5505 but I do not believe it yet.

Posted on: 15 June 2018 by Simon-in-Suffolk

I would have thought you just need to look at these device logs ... and check to see if PIM is redistributing the multicast across the subnets. From a point of view SSDP, the protocol uses a multicast group address, and that is what you need to check rather than anything else.

However as I said I keep all my home domestic wlan and audio in the same subnet... that helps with mDNS etc that Apple uses too... but as the ASA5505 is really a firewall as opposed to a general router there may be some funnies in there.

IGMP must be enabled which is usually automatic on Cisco router when multicast routing is enabled.. looking on the web others have successfully routed SSDP on Cisco routers.

ip multicast-routing
!
int <to replay1>
ip pim dense
!
int <to replay2>
ip pim dense
...

Posted on: 16 June 2018 by Revoliño

So I finally got it to work.

The interface my NAC-N 272 is connected to didn’t have IGMP enabled on it, which should be enabled after my multicast-routing command. So after disabling and enabling multi-cast routing, I’ve come to known that IGMP was succesfully enabled on all the interfaces and the Naim app could find my 272 again.