[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[Linrad] Linrad network connections
- Subject: [Linrad] Linrad network connections
- From: Joe Taylor <Princeton.EDU; joe@xxxxxxxxxxxxxxxx>
- Date: Thu, 24 Jul 2008 17:02:23 -0400
Today I've been playing with the Linrad+MAP65 combination, in
preparation for making some demonstrations at the EME Conference in
I noticed something that may be interesting to others on this list.
You'll recall that Linrad serves as a "front end" to MAP65. Digital
data in the Linrad "timf2" format, taken after the first inverse FFT,
are sent over an ethernet connection to MAP65. The default Linrad code
does this transfer in the form of multicast UDP packets. Multicast
means that there is one source of packets -- Linrad -- and in principle
there may be many receivers. Many months ago I changed my working copy
of Linrad (version 02.34) so that instead of multicast it uses
"unicast". That is, data are sent explicitly to a single IP address,
that of the machine running MAP65. This resulted in more reliable data
transfer -- and also, even more importantly, it prevented swamping my
local network with Linrad traffic so that my wife could not use the
network to check her email, etc.
Today I discovered another big advantage of sending unicast rather than
multicast packets. On my network, at least, multicast transfers make
*much* more RFI. Every packet transfer is clearly audible on an HF
receiver tuned to the 30 m band. I don't hear anything at all when I
switch to making transfers to a single IP address.
-- 73, Joe, K1JT
You received this message because you are subscribed to the Google Groups "Linrad" group.
To post to this group, send email to linrad@xxxxxxxxxxxxxxxx
To unsubscribe from this group, send email to linrad-unsubscribe@xxxxxxxxxxxxxxxx
For more options, visit this group at http://groups.google.com/group/linrad?hl=en