[OpenSIPS-Users] mediaproxy stops relaying packets

[Jeff Pyle]

Hi Ruud,

I still need to run the tests you've asked for.  Time hasn't allowed yet.

I can tell you it works with some PSTN gateways, but others give the
symptoms described here.  All PSTN gateways are "off-net", that is, beyond
the default gateway.  I can tell you eth0 of the box is for data /
management, while eth1 is for the voice activities.  They have IPs on
different networks.  Mediaproxy-relay is bound to the IP of eth1.  There are
route tables that set the next-hop of the packet based on the source
address, which the relay doesn't seem to honor for some reason.  It's not a
big deal if it leaves the wrong interface, unless it causes
less-than-obvious problems.

Results to follow...


- Jeff




On 7/22/09 8:47 AM, "Ruud Klaver" <ruud at ag-projects.com> wrote:

> Thanks for the comprehensive traces, it's a bit of a mystery indeed.
> 
> First of all, are you sure there is a correlation between the gateway
> being used and mediaproxy working or not? Are all hosts on public IPs?
> 
> Indeed the relaying stops once the first packet from the user endpoint
> is receives. Up to this point the relay does not know what the ip/port
> of the caller, so the forwarding is performed in userspace. When it
> receives the first packet from the caller, it learns its ip/port,
> forwards the received packet through userspace and creates the
> connection tracking rule.
> 
> Now for some reason the connection tracking rule doesn't seem to work,
> but from what you gave me I cannot tell you why not, but this is the
> direction you have to search in. A few questions you could look into:
> - Are the connection tracking rules working for some calls but not for
> others?
> - Are all the IPs involved public, i.e. are they using the same
> interface?
> - Is the connection tracking rule actually installed, you can check by
> using doing "conntrack -L" and grepping the list
> - Is ip packet forwarding enabled in the proc filesystem?
> - Is anything else on the system blocking forwarding of packets (maybe
> in the FORWARD table)
> 
> In fact, what was that you mentioned about iptables?
> 
> Ruud Klaver
> AG Projects