[PD] UDP server with Pd

Martin Peach chakekatzil at gmail.com
Mon Jun 7 21:34:42 CEST 2021

OK, I have implemented something that might work: [udpsrvr] can listen
on a port and send to an address using the same or a different port.
The only problem I see with it is that while the socket is connected
for a send, it won't receive anything. I overcome this partly by
sending the connect/send/disconnect sequence in one comma-delimited
The code is at


On Mon, Jun 7, 2021 at 3:48 AM Roman Haefeli <reduzent at gmail.com> wrote:
> On Sun, 2021-06-06 at 20:26 -0400, Martin Peach wrote:
> >
> >
> > If you have a [udpreceive 9898] as your 'server' it will receive from
> > anywhere on port 9898. So you can take the sender's ip and port from
> > the latest incoming message (route 'from' at the second outlet) and
> > use them to set the address and port of a single [udpsend] for the
> > reply.
> > There is no connection in udp so you need to add metadata in your
> > datagrams for routing and so forth.
> Again, this does not work. The socket on the client side will only
> accept packets originating from the port it has sent packets to, but
> [udpsend] on the server cannot use this port as bind port, because it
> is already occupied by [udpreceive]. To put this into telephone
> analogy: When you call someone, you expect a third party to be
> prohibited from shouting into your call, and you expect to hear only
> the party you called.
> The only solution to this is to use the same socket for both sending
> and receiving, as Christof already suggested.
> Roman
> _______________________________________________
> Pd-list at lists.iem.at mailing list
> UNSUBSCRIBE and account-management -> https://lists.puredata.info/listinfo/pd-list

More information about the Pd-list mailing list