July 2021 - Udpcast

Using UDPcast in a C program directly as a function
by cyber work 18 Jul '21

18 Jul '21

Dear sir, I would like to start by thanking you for your work on udpcast as it has been very useful for a lot of people and companies. I am reaching out in order to get some insight on how to use udpcast (sender & receiver) directly in C code without executing it from a bash call. To be clear, I would like to know if there is some kind of documentation on how to use these programs in C as functions that I could call. So far, every program that I have seen uses udp-sender and udp-receiver by a bash call inside a C or python code. This does not suit me because it slows significantly the speed of the program. Thanks a lot

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option --nokbd doesn't send data
by Luke Robison 14 Jul '21

14 Jul '21

I am trying to push data through a one-way pipe in an automated way using udp-sender and udp-receiver. I have a working example, but can't get the --nokbd option to work on the sending side. Working Sender: yes | ~/udp-sender --async --fec 8x6/64 --max-bitrate 500M -f tmp_send_tarball.tar Receiver Command: ~/udp-receiver --pipe ~/rx_hook.sh --nokbd But notice I have to pipe the "yes" command into udp-sender to trigger the start from udp-sender. When instead I use --nokbd on the receiver, it hangs waiting for something after the control message. True to the documentation, it doesn't ask nor accept input, but it seems to fall into a default of "don't send" rather than a default of "send immediately" as I would expect. $ ~/udp-sender --async --fec 8x6/64 --max-bitrate 500M -f .tmp_send_tarball.tar --nokbd stripes=8 redund=6 stripesize=64 Udp-sender 20200328 Using mcast address 234.14.136.217 UDP sender for .tmp_send_tarball.tar at 10.14.136.217 on eno3 Broadcasting control to 10.14.143.255 <hangs here...> Am I missing something? Respectfully, Luke

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Two or more clients drops bandwith by 2 orders of magnitude
by Brent Kimberley 07 Jul '21

07 Jul '21

William Please ensure you are using UDP/IGMP. Brent Hi, (I hope this list is still active) I am a newbie. I am testing multicast support on three computers connected through a gigabit switch. When only the server, ran as (rand.bin is a 1Gb file) udp-sender --interface eth1 --file rand.bin and ONE client udp-receiver --file rand.bin are connected, the bandwidth is around 937.32 Mbps, which is very good. But with two or more clients if consistently drops to 11 Mbps I would expect to bandwidth to decrease as 1/N, where N is the number of clients. What am I missing? I am using a dumb switch. Thanks -- Best regards / Cordialmente, William-Fernando Oquendo -------------------------- Este correo puede carecer de tildes o e?es debido al teclado. THIS MESSAGE IS FOR THE USE OF THE INTENDED RECIPIENT(S) ONLY AND MAY CONTAIN INFORMATION THAT IS PRIVILEGED, PROPRIETARY, CONFIDENTIAL, AND/OR EXEMPT FROM DISCLOSURE UNDER ANY RELEVANT PRIVACY LEGISLATION. No rights to any privilege have been waived. If you are not the intended recipient, you are hereby notified that any review, re-transmission, dissemination, distribution, copying, conversion to hard copy, taking of action in reliance on or other use of this communication is strictly prohibited. If you are not the intended recipient and have received this message in error, please notify me by return e-mail and delete or destroy all copies of this message.

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Two or more clients drops bandwith by 2 orders of magnitude
by William Oquendo 03 Jul '21

03 Jul '21

Hi, (I hope this list is still active) I am a newbie. I am testing multicast support on three computers connected through a gigabit switch. When only the server, ran as (rand.bin is a 1Gb file) udp-sender --interface eth1 --file rand.bin and ONE client udp-receiver --file rand.bin are connected, the bandwidth is around 937.32 Mbps, which is very good. But with two or more clients if consistently drops to 11 Mbps I would expect to bandwidth to decrease as 1/N, where N is the number of clients. What am I missing? I am using a dumb switch. Thanks -- Best regards / Cordialmente, William-Fernando Oquendo -------------------------- Este correo puede carecer de tildes o eñes debido al teclado.

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