atcomsystems.ca/forum Forums TDM Business Telephone Systems Samsung Telephones & Systems SIP - Can dial OUT but not IN

We've recently switched over from PSTN to a SIP trunk service.

We're having 2 PSTN numbers ported to the SIP, had our backup line moved first in case we run into a problem (like now!)

Our supplier doesn't offer technical support for the Officeserv system so we're abit on our own. I has an engineer initially setup the system and everything seems ok but ive since realised...

We can't dial INTO our number unless we've previously dialed OUT within the last couple of minutes.

Its as if the connection between the SIP server and Officeserv gets terminated.

Ive also noticed it takes almost 10 seconds between dialing the number to it actually dialing out, we get a message saying ALERT_IN then it dials.

If these are any help, i can post other screens if needed.



Eventhough DID Ringing is set to ring Port 517 (Auto Attendant) it doesnt! just rings 500



Any help would be appreciated.

Thanks,
Ashley

Hi Ashley,

The issue isn't in the phone system but rather your firewall/router which must be closing the pinhole created when outbound SIP traffic passes through. There are a number of potential fixes:

1. Turn off SIP ALG in the firewall
2. Shorten the registration timer for the SIP trunk in your phone system to something like 60 seconds
3. Create an inbound rule in your firewall that forwards traffic on port 5060 to your phone system. IMPORTANT - restrict this rule to only allow IP addresses of your provider through!

Everything Toner said, and also, create firewall rules for the RTP side of things as well. These ports start at 30000. 40000 and 45000 for different things and follow a range depending on how your system is configured. Look at settings in 2.2.2 and 2.2.15 for an idea of what ports need to be opened.

In 5.2.17 it is also worth setting the alive check to options, putting the word sip in the User Information column and dropping the check timer to something like 60 seconds and then rebooting

Thanks Toner, JBean3329, SamsungCat - the phones are now ringing! IN and OUT

I ended buying a newer router too (the model our supplier was recommending), together with your tweeks it's working.

I set the incoming firewall like this....
My gut feeling is the second line ins't needed but was reluctant to remove in case it brakes something haha

Great to hear, thanks for letting us know! You're correct - the 2nd rule isn't needed, especially because it describes outgoing traffic but the "Traffic Type" is INCOMING