[OpenSIPS-Users] Mediaproxy receives only

[Dan Pascu]

On 9 Sep 2009, at 23:50, Schumann Sebastian wrote:

> Hi
>
> What could be a possible cause of mediaproxy (current src) to only  
> receive media from both parties but not to relay it.

There are a number of possible causes:

1. Check that there is no iptables rule blocking the traffic
2. Make sure IP forwarding is enabled:
    /proc/sys/net/ipv4/ip_forward should be 1
3. Make sure rp_filter is disabled:
    /proc/sys/net/ipv4/conf/all/rp_filter is 0
    /proc/sys/net/ipv4/conf/default/rp_filter is 0
    /proc/sys/net/ipv4/conf/eth0/rp_filter is 0 (replace eth0 with  
whatever interface you use)

The settings are controlled at boot time from /etc/sysctl.conf by the  
following options:

net.ipv4.ip_forward=1
net.ipv6.conf.all.forwarding=1

net.ipv4.conf.default.rp_filter=0
net.ipv4.conf.all.rp_filter=0

o modify them at runtime without rebooting, just echo the right value  
in the /proc filesystem files I mentioned above.

> Traffic goes from both clients to the mediaproxy, but the mediaproxy  
> only sends one packet in the beginning to both clients and then not  
> again...

That's because the first packets (until both endpoints are discovered)  
are forwarded in userspace, but after that they are forwarded using ip  
conntrack rules.

--
Dan