[omniORB] omniINSPOA and bidir connections (omniORB4)

[Duncan Grisby]

On Wednesday 23 October, "Fernando A. de Araujo Filho" wrote:

> Well, in any case. I have to learn much more...
> Is madness think about "H.261 or  H.263 or mpeg4" over IIOP ?

At AT&T, we had an omniORB demo that streamed uncompressed CD quality
audio from multiple sources to multiple sinks, over a LAN. Each stream
was 1.5 Mbps. It worked fine with plenty of endpoints. You should have
no difficulty streaming compressed video in similar circumstances.

That said, CORBA isn't an especially sensible way to stream multimedia
data, since CORBA has a request-reply model built on top of a reliable
stream protocol (TCP). To stream data, you end up doing your own
segmentation and reassembly on top of all that, replicating the work
TCP is already doing for you. If network latency is high, you start
having to mess around with sending from multiple threads, just to
avoid being held up waiting for the replies that you don't actually
care about. Alternatively you use oneways, and you have to be careful
to throttle the sender (if the data isn't live). If the network isn't
especially reliable, TCP retries mean you get random delays and huge
jitter.

I think it's far more sensible to use CORBA as the control
infrastructure for data streamed by more appropriate means, like just
a raw TCP socket, or UDP if you'd rather lose packets than be held up
with retries.

Cheers,

Duncan.

-- 
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