Strange silence and disconnects

[danavni]

i have 3cx 10 with around 20 snom 300 phones connected.
i got more than one report from users that internal calls between extensions at some point during the conversation becomes silent and each side can not hear the other. the call remains connected but at least one side can not hear the other.

how do i fix this or find the cause?

 

[eagle2]

This could be a LAN issue -- try using Wireshark to capture and investigate the VoIP traffic.

What machine are you using for 3CX server. Can this computer being loaded too much?

 

[danavni]

the 3cx machine is a new multi core machine with windows 7 and it does nothing but service the 3cx
nothing installed on it not even an anti virus and the firewall is off

as for the lan issue, just so i'll understand where to look (i am familiar with wire shark), when two internal extensions are talking is the traffix sent directly between them or does it pass through the PBX?

 

[eagle2]

Hi,

by default the RTP traffic (i.e. voice) is point-to-point, nevertheless you can force it passing through the PBX (which could be quite useful for external extensions in some cases) -- by clicking on 'PBX delvers audio' in extension settings in 3CX server.

Assuming your voice traffic is point-to-point, can you have problems with the LAN throughput between the phones, e.g. bottlenecks, problems with the switch etc.? If so, think of implementing QoS, VLAN or physically separate LAN for the phones. Having moments of silence means either delayed or lost packets. Have you tried adjusting the jitter buffer in the phones? Is there something logged into the 3CX server?

 

[Discovery Technology]

Could be the firmware version on the Snom handsets also - if you aren't running 7.3.30 then this could be your problem.

Try this firmware version on a few handsets showing the symptoms and see how you go.