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

[Luca Bertoncello]

Am 22.06.2020 um 22:12 schrieb Marek Greško:

Hi Marek

> Would you mind repeating the test with canreinvite=no set for all you
> phones and mobile phones?

All my peers have already canreinvite=no...
I only have canreinvite=yes on the SIP configuration on the Telekom part:

[pbxluca]
type=peer
defaultuser=111111111 at t-online.de
secret= xxxxxxxxxx
dtmfmode=rfc2833
host=tel.t-online.de
context=luca_incoming
outboundproxy=tel.t-online.de
port=5060
fromuser=03511111111
fromdomain=tel.t-online.de
usereqphone=yes
canreinvite=yes
insecure=port,invite
nat=no
qualify=yes
qualifyfreq=600
disallow=all
allow=alaw
allow=ulaw

Should I change canreinvite=no there?

> What is your upload bitrate? Is it guaranteed?

Currently 12Mbps. Guaranteed should be about 10Mbps...

> I would try also to test the PMTU:
> 
> Try:
> 
> ping -M  do -s 2000 ${ip address of the sip server}
> 
> You should receive icmp asking for lowering the packet size.

root at bpi:/etc/asterisk# ping -M  do -s 2000 tel.t-online.de
PING tel.t-online.de (217.0.128.133) 2000(2028) bytes of data.
ping: local error: Message too long, mtu=1492
ping: local error: Message too long, mtu=1492
ping: local error: Message too long, mtu=1492
ping: local error: Message too long, mtu=1492
ping: local error: Message too long, mtu=1492
ping: local error: Message too long, mtu=1492
^C
--- tel.t-online.de ping statistics ---
6 packets transmitted, 0 received, +6 errors, 100% packet loss, time 5103ms

Mmmm... it seems not good, isn't it?

For information, here the output of ifconfig:

dsl0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1492
        inet 93.241.x.y  netmask 255.255.255.255  destination 62.156.z.k
        inet6 fe80::9565:3024:4deb:ebc7  prefixlen 10  scopeid 0x20<link>
        ppp  txqueuelen 3  (Point-to-Point Protocol)
        RX packets 852397  bytes 480197087 (457.9 MiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 967912  bytes 170822532 (162.9 MiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

> The LTE phones could have lower MTU and thus overcome PMTU problem.

Should I reduce the MTU?!?
Maybe I didn't understood what you mean...

Thanks
Luca Bertoncello
(lucabert at lucabert.de)