On Fri, May 06, 2011 at 09:35:50AM +0300, Alex Badea wrote:
Specifically, I had the gsmtap packets sent over the network (i.e., non-localhost). There was no UDP listener on the receiving end, such that ICMP port-unreachable replies were being sent back. It would appear that this causes the sender's kernel to snub some of the outgoing packets. I don't know if the same happens on localhost.
it happens on localhost, too.
If this is your case, you can try "iptables -I INPUT -p udp -d 4729 -j DROP", or something like "nc -l -u 4729 > /dev/null".
The other workaround is to use "nc -l -u -p 4729 >/dev/null" to create a process that listens on UDP port 4729 and sends all packets to /dev/null.
I've recently added a gsmtap_sink to libosmocore. Once we use this from our various projects like OsmocmBB, there will be no need for any of those kludges anymore.