Posted by: Claudio Carbone | 18 July 2011

And the OLD won over the NEW another time.

So I finally got myself a shiny new NAS.

What is a NAS? Easy: it’s a networked drive! It sits there, holding your data, always available.
The more you pay, the more things it can do: download things for you, schedule backups, mirror your data to enhance security, and more.

So my new Netgear ReadyNAS NV+ is on the low end: 200€ diskless.
It doesn’t even have an x86 cpu, instead it sports an aged Sparc (once Sun) and 256 MB (!!!) of ram.

Netgear Readynas NV+

Netgear Readynas NV+

But it can be loaded with up to 4 2TB discs, bringing its total capacity to 6TB with data redundancy to help protect from disk failure.
AND it has embedded streaming support.
So I can offload my media collection to my nas and play it from anywhere in the house: the net connected TV, my laptop obviously, but also my phone! Nifty!

And here I learned something.
This whole “streaming” shebang that goes all the rage these days, in its home incarnation is based on a commercial arrangement called DLNA. This is a modification of an already existing protocol, to allow different devices to interact and exchange multimedia data over a network.

The basic principle below is broadcasting on the network the existence of the streaming server.
And here all the theory fails: I read some forums, articles, blogs, and did my own tests, confirming inevitably that, should your wireless gear (Access Point, router, whatever) be older then some point unknown, you can’t swim in streamed music over wireless.

The broadcast messages needed for the streaming to work are simply ignored by wireless stations.
Bot my ADSL modem/router with integrated access point, and an el-cheapo access point that has served me for 4 years and still would if I needed it to, don’t work.
While a newer WIFI N access point (D-LINK DAP 2553) doesn’t have any problem.

So my phone can’t see the multimedia server, because it uses the old wireless, while my laptop can because it uses the new N wireless.
And I’m not joking!
I’ve stared for hours at the packet sniffer, hopping from one net to the other, trying to understand what was going on: packets simply weren’t farwarded to the wireless network. At first I though in a problem derived from a configuration error, but the more I looked at it, the more I couldn’t find an error, nor a logic: everything else worked, even direct pinging, just the broadcast packets were nowhere to be found.
And more telling was that, when hooked from the N wireless, I could see the broadcast packets in answer to the phone requests, but when hooked on the standard wireless, I couldn’t see them.
So this was a confirmation that the packets were indeed sent, but that they were blocked at the frontier between wired and wireless.
And that meant that it was the AP blocking them.
So I took out from storage the old standalone AP (before I got the new integrated modem/router/ap) and it showed the same behaviour.

My final take is that, somehow, older devices don’t correctly forward certain types of packets, most notably those now used by streaming protocols.
This in turn means that, should I really want to have wireless streaming, I should search for a new device probably labeled as “multimedia” or “AV”.




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