Random Question for Help


Am am getting a really odd issue where when my ISP drops my internet connection my PBX doesn’t come back online on the external link correctly all the time, Sometimes it works fine though.
Does anyone have any suggestions on how to fix this maybe?
If this is not a PBX issue then i will gladly take it up with My ISP as they have been giving me shocking service lately.

My trunks deregister when the internet drops out but dont re-register when it comes back up.
If i do a manual IFdown and IFup it starts working immediately afterwards.
Like i said random question.

It’s not quite as random a question as one would hope - we see phones to do this quite often.

An extract of your /var/log/asterisk/full log could help. Find the spot where the system disconnects and watch to see what happens when it retries. This should help you figure out what the root cause of the problem is. If it’s simply that the network is dropping and reconnecting, you should look at the entire circuit and not jump straight to the ISP being the cause.

There are a couple of settings that may help - you might need to adjust a couple if your trunk options to tune this. We won’t really be able to give you any good suggestions without more troubleshooting.

Thanks, i will look at this tomorrow.
The main reason i am jumping to the ISP is because it is connected directly to their Breakout Equipment and our office internet drops out around the same time but the internal connection to the PBX stays active.

Basically my setup is as follows:
ISP Equipment -> Direct link to ETH0 on PBX
-> Direct link to Company firewall

And on PBX ETH1 we have a link to the Local LAN without firewall interaction.

I will keep it in mind and still do waht you suggested when i am back in the office tomorrow morning my time.

Your basic network setup sounds suspicious.

You should have your ISP Demark connection - their equipment.

Coming out of that, you should have two connections. One to your phone server (call that ETH0 on the phone server) and one to your corporate firewall.

Your phone server may also be connected to the local network (call that ETH1 on the phone server). If you have it set up so that the local LAN can connect to the Internet, it is possible that you are creating a “path” to your ISP through the ETH1 connection. This could keep your ETH0 connection from reconnecting. It’s just something to look at.

Setting your system up with a public side and private side are well understood connection methods and are both recommended. Double check your network settings, especially in your routing settings on the server, to make sure you aren’t possibly instantiating a false leg that the server will try (and fail) to use.

Not sure if this explanation will sound better, from how i understood i got the network setup correctly, I will however be the first to admin i may possible have it wrong.

We have our ISP equipment that has two LAN cables coming out of it, one to our corporate firewall and one to our phone server on ETH0.
We then have our corporate network connected to the trusted interface on the corporate firewall and we have ETH1 on the phone server connected also to the corporate network with a static IP address and no gateway or internet routes (as far as i know, like i said it is possible i got this part wrong).
The only internet connection, as far as i can tell, on the phone server will be on ETH0 going directly to the ISP equipment, We have a dedicated VOIP tunnel on the ISP side through the port we are using.

As far as i can tell the local LAN for the Business can only go out through the firewall and the Phone server on ETH1 doesn’t see the internet.

Please correct me if i am wrong though.

Many thanks

Sounds right. On to the rest of the possibilities.

Have you looked at your logs to see what the system thinks is causing the problem?

The closest thing i can see in the logs and it happened about 4 days ago was this
[2017-06-23 14:54:50] VERBOSE[3440][C-00001924] chan_sip.c: Got SIP response 500 “Disconnected” back from “SIP Provider”

I went through yesterdays logs and there is nothing like that or even anything stating that it was disconnected except from the phones when the power dropped out on some of the desks.

I went through the log that you mentioned above (/var/log/asterisk/full) and i went through the ones labeled with older dates on them.

Any other suggestions or maybe im just not understanding the logs?

That’s the error we’re looking for.

Now, Google “Asterisk 500 error reconnect” and see what pops up.

https://www.voip-info.org/wiki/view/SIP+response+codes is a good start.

Thanks so much for this, Maybe next time i do a setup like this i wont be so noobish, so far everything is self taught or from this forum.

I have read up on it and it suggests to enable SIP debugging and go through those logs after it happens again which i will do.

Again thanks so much for the help.

Keep coming back - the answers you get are required for us to help you. There are SO many things that can go wrong that pointing you in the right directions on the questions you should ask is sometimes the shortest route to getting you where you want to go.

I will keep coming back thanks.

I didn’t mean that i would stop at this point, sorry if i implied it, i just mean i have now got the next step and i will run through it and post my findings.

One thing i will do is always try to update a “issue” like this with a solution so that anyone who comes after with the same problem will be able to have some sort of guideline to solving it themselves, I have come across a few where the Poster just says “thanks i have fixed it” and no one knows how or what he did as he never came back to the post.

Again thanks.