[asterisk-users] Voice broken during calls (again...)

[Luca Bertoncello]

Am 23.06.2020 14:49, schrieb Marek Greško:

Hi Marek,

> this could be ip address of the different interface on the same box. I
> think it works like expected. The only exception would be if the sip
> peer ignores the icmp packet unreachable. But I doubt this is the

Do you mean "my Linux-Box ignores ICMP packet unreachable" or "Deutsche 
Telekom ignores them"?

> case. Anyway you get problems also when calling to LTE phone without
> using sip provider.

I have problem calling someone outside my networks and I have problem if 
the peers are in different networks...

> Let first concentrate on these calls LTE to LAN. Are you sure you do
> not block incoming icmp unreachables? At least verify type 3 subtype 4
> is enabled. If it is, I have no clue what is going on.

Well, I limit incoming ICMP packets and I block some hosts (known 
crackers)...
If you think, I can send you the script I use (with iptables) to manage 
my firewall, so you can check it...
The only entries I have, having something to do with ICMP, are:

----------------------------------
/bin/echo -n "Disable ICMP Redirect acceptance..."
for f in /proc/sys/net/ipv4/conf/*/accept_redirects; do
   /bin/echo 0 > $f
done
/bin/echo "done."
/sbin/iptables -A INPUT -i dsl0 -p icmp --icmp-type echo-request -m 
limit --limit 6/m --limit-burst 5 -j ACCEPT
/sbin/iptables -A FORWARD -o dsl0 -p icmp -j ACCEPT
----------------------------------

and of course other rules to allow ICMP pakets in the internal 
networks...

Thanks a lot
Luca Bertoncello
(lucabert at lucabert.de)