Thin clients that support sound

[DaveA]

Hi,
We are looking into using thin clients within the school but I have been asked to find ones that can support audio. I was woundering if anyone can give me some advice about what make and model to look into that lets you have audio on them.

Dave.

[nut-ed]

Sound is problematic as it is realtime by definition, and TCP/IP is not. So when the bandwidth limit is reached, rather than an application running a bit slow, the sound will tend to blip in and out like a bad mobile signal.

PC's tend to buffer sound then play it when stored locally, thin clients don't normally have this ability so are 100% dependent on pulling sound over the network. As sound is by definition reasonably bandwidth hungry, pulling multiple sound streams over the network will have an impact on bandwidth, reducing further the ability to deliver sound fast enough to be 'realtime' and work properly as far as ears are concerned.

TCP/IP works best in bursts followed by lulls, giving a high average bandwidth. Sound requires a "consistant" stream of data. So both your max bandwidth, and bandwidth usage have an impact

A further limitation is Microsoft terminal services does not syncronise video to sound and only supports sound in one direction (supports speakers, not microphones),

Citrix is more deleloped in this respect and does support sound in both directions and does syncronise, but comes with a hefty price tag...

Maybe someone else can give a more positive message - it has been a while since we looked at this - but I guess the fundamentals haven't changed much...

Pretty much all thin-clients seem to support sound, there are various posts on problems on Edugeek, the point is not thin-clients supporting sound - more of the ability to get sound to the thin-client !!!!!

[Geoff]

What applications are you using that require audio? If your doing heavy multimedia work for example, thin clients will be unsuitable for your workload anyway.

[localzuk]

If it is just playing sound (for example, playing a youtube video), I can confirm that HP T5735's with Citrix as the backend work fine.

But I'd never even contemplate using them for anything more than that.

[Axel]

We can loan you a couple of thin-clients if you wish to see their operation in the flesh, currently we do not support sound, as thin client technology is not really condusive to sound (or video)

We are however developing drivers for sound, so will be a free firmware upgrade in a month or so for the M80f terminal - as displayed on the Edugeek stand at BETT last week.

Q: Why are we developing sound if we feel it is not condusive...?!?!?
A: Because users ask for it, it is relatively simple for thin clients to support sound, the hard part is having servers/networks that can deliver it.

Apart from sound/video the M80 gives the same performance as a PC when connecting over RDP.

If you would like to trial one please click here:
AXEL: request a demo unit from Axel Ltd.

[Ric_]

Sun Rays and anything that fully supports the Citrix ICA client will support sound.

With Citrix XenApp you can also define what quality of sound the client receives so that you can save bandwidth.

Audio does work with thin clients.

[dhicks]

Sound is problematic as it is realtime by definition, and TCP/IP is not

But UDP is, couldn't sound be transmitted using that instead?

Sound works fine on our thin clients, never really given it much thought. Just going to start doing some podcasting, too, so I guess we'll see just how well it works.

--
David Hicks

[nut-ed]

... is UDP an option for sound over RDP...?

How many pupils can concurrenty "use" sound...?

[dhicks]

... is UDP an option for sound over RDP...?

I don't know, we use LTSP for our thin clients. Is the OP definitely using RDP-based clients, then, or is he asking for just any model of thin clients that will support sound?

How many pupils can concurrenty "use" sound...?

Good question - to be honest, other hardware limitations (lack of headphones, too noisy with all the speakers going, Internet bandwidth limits for 18 clients all accessing YouTube) have been met before we've had a chance to find out.

--
David Hicks

[linescanner]

Sun Ray use UDP. The sound works fine on them. I have a school running LTSP on HP T5xxx series thins and sound works here also.

[Butuz]

I regularly listen to Radio1 live on HP thin clients and the sound seems to work OK apart from a very occasional slight stutter. It was using 4% CPU when I was listening.

Never tried concurrent users though.

Andrew