11 Sep
2004
11 Sep
'04
3:42 p.m.
In pratice people dont really demand hard realtime and
it will be OK, but
the maximum time taken to transmit a UDP packet is unbounded, it uses
exponential backoff IIRC.
That sounds like TCP. I think UDP is send and forget, if you want guaranteed
delivery or sequencing you need a higher protocol like TCP.
Or are you thinking of ethernet level collision detect and retransmit? Does
that go on forever (unbounded)?
(Sorry I know it's an older thread, I'm trying to catch up ;-)
12 Sep
12 Sep
6:18 p.m.
On Sat, Sep 11, 2004 at 10:25:53AM -0700, Andrew Burgess wrote:
I dont think so, but IP (including UDP) does. There is a difference
between raw ethernet packets and UDP.
Ethernet has checksums to detect problems (maybe in;c forward correction),
but AFAICR it doesnt retransmit on its own, I would imagine that that is
why the commercial audio-over-ethernet systems work.
- Steve
In pratice
people dont really demand hard realtime and it will be OK, but
the maximum time taken to transmit a UDP packet is unbounded, it uses
exponential backoff IIRC.
That sounds like TCP. I think UDP is send and forget, if you want guaranteed
delivery or sequencing you need a higher protocol like TCP.
Or are you thinking of ethernet level collision detect and retransmit? Does
that go on forever (unbounded)? 
13 Sep
13 Sep
12:41 a.m.
Steve Harris wrote:
On Sat, Sep 11, 2004 at 10:25:53AM -0700, Andrew
Burgess wrote:
I dont think so, but IP (including UDP) does. There
is a difference
between raw ethernet packets and UDP.
Ethernet has checksums to detect problems (maybe in;c forward correction),
but AFAICR it doesnt retransmit on its own, I would imagine that that is
why the commercial audio-over-ethernet systems work.
So at what level in the tcp/ip stack does a collision get detected? From
what I understand, if there is a collision on a network segment each end
will backoff for a randomly chosen time and then retransmit. Is this at
the ethernet, IP, or TCP level?
-Eric Rz.
In pratice
people dont really demand hard realtime and it will be OK, but
the maximum time taken to transmit a UDP packet is unbounded, it uses
exponential backoff IIRC.
That sounds like TCP. I think UDP is send and forget, if
you want guaranteed
delivery or sequencing you need a higher protocol like TCP.
Or are you thinking of ethernet level collision detect and retransmit? Does
that go on forever (unbounded)? 
6:48 a.m.
Eric Dantan Rzewnicki <eric(a)zhevny.com> writes:
Steve Harris wrote:
Ethernet. Back in the coaxial days collisions were much more liikely
than with todays topologies. But Ethernet collision detection
doesn't retransmit forever, just for a limited amount of time.
UDP is indeed unreliable, you just inherit the ethernet collision detection
(if you are using ethernet as a lower-level protocol).
UDP doesn't guarantee arrival, nor does it guarantee order of arrival.
--
CYa,
Mario
On Sat, Sep 11, 2004 at 10:25:53AM -0700, Andrew
Burgess wrote:
I dont think so, but IP (including UDP) does. There
is a difference
between raw ethernet packets and UDP.
Ethernet has checksums to detect problems (maybe in;c forward correction),
but AFAICR it doesnt retransmit on its own, I would imagine that that is
why the commercial audio-over-ethernet systems work.
So at what level in the tcp/ip stack does a collision get detected?
From what I understand, if there is a collision on a network segment
each end will backoff for a randomly chosen time and then
retransmit. Is this at the ethernet, IP, or TCP level? In pratice
people dont really demand hard realtime and it will be OK, but
the maximum time taken to transmit a UDP packet is unbounded, it uses
exponential backoff IIRC.
That sounds like TCP. I think UDP is send and forget, if
you want guaranteed
delivery or sequencing you need a higher protocol like TCP.
Or are you thinking of ethernet level collision detect and retransmit? Does
that go on forever (unbounded)?
7470
days inactive
7472
days old
linux-audio-dev@lists.linuxaudio.org
3 comments
4 participants
participants (4)
-
Andrew Burgess -
Eric Dantan Rzewnicki -
Mario Lang -
Steve Harris