INVITE strange

[aleshiukas]

Hi !

I am experiencing strange problem when testing calls at home locally.

I am not using any VOIP provider, have 2 extensions registered and trying to make call from one to another,
all on local network.
Sometimes, called extension is ringing immediately, sometimes it delays for 15-20 secs before ring.

Analyzing traffic on 3cx server when there is a delay, I noticed:
- SIP INVITE packet arrives immediately
- after few time, it is resent from the calling extension
- after 3rd resend, calling extension starts ringing
- all 3 SIP INVITE's are byte to byte the same

Comparing time between 3cx verbose log and wireshark, I see log of the call starts with the 3rd invite, like the previous 2
are totally ignored (which actually causes a ring delay)

I also have local IP's in hosts file for any case (so DNS is not an issue here, they resolve immediately)


Any hint why 3cxPhoneSystem is ignoring/delaying (there is no entries in verbose logs for the first two SIP INVITE's)

 

[NikosT_3CX]

Hi,

as you can understand your scenario needs to be examined through wireshark capture and Support files at the same time .
There are a lot of factors that the Invite message is not forwarded. Depends on the phones you are using, the machine that the PBX is installed, as well the connectivity on your network. If your phones do not have the supported firmware or if the machine that the PBX is installed has a lot of Applications that block the requests of being transmitted. Some anti-virus applications may cause this or if your machine is not full updated.
Please open a ticket on your support portal if you have access in order to investigate your case and provide you a solution.

 

[aleshiukas]

Hi !

All investigation is done on 3cx server. As I said, packet arrives (I am using 3cxPhone original sw client),
they're just no processed until the 3rd SIP Invite comes in. There is no tcp/udp stack issue as well.
It started suddenly to happen this. As all three SIP invites are binary the same, there is also not SIP issue.
But even verbose log enabled, I cannot tell what 3cx server is doing at that time (with first two packets, which successfully
are received by UDP stack into the server machine).