Busy Signal Every 8-12 hours

[b_stimp]

I'm supporting a IP phone system that is running a NetVanta 7100 series on the back end.

About 7-10 days ago we have started to get a busy signal approx. every 8-12 hours.  The busy signal is when calling in or using any outside lines to call out.

Internal connections and phones appear to be working just fine.  Netvanta is pingable and able to login and looks to be running ok (low CPU usage and average memory usage).

Logs appear to be somewhat normal.

I have to restart the Netvanta from the web interface and after doing so outside lines begin to work as they should.

I can think of no changes on the network or servers that would cause any routing issues.

Phone company says they see a line "off hook" when the problem arises and they point to our end as the problem (no technician has been onsite as of yet).

I'm stumped as to why the outside lines just stop working and show as busy/off hook.  Again this is starting to happen approx. every 8-12 hours.

Any ideas?  I'm new with this type of equipment so I apologize for my lack of details.

[jayh]

Is the Netvanta connected to earth ground, preferably at the same point as the telco protector at the demarcation point? If not, do this first.

When the system locks up, if you disconnect the incoming central office line from the Netvanta and call it from another phone such as a cell phone, does it still give a busy signal or does it just ring?

You say outside lines, does this happen on all lines or just the main number? Are the lines in a series completion (hunt) setup?

What does "show interface fxo [interface number] show when it goes busy?

[b_stimp]

I will check ground to see what the current setup is.

When the system stops working it will sometimes be a busy signal dialing in and other times it will just ring forever.

For example, this morning around 1 am I tested the line and the system would not pick up, it just rang.  Typically after 2 rings an Auto attendant would pick up giving the caller a couple options.  Originally I would see this problem every 8-12 hours, but it is far more inconsistent than before.  Sometimes after restarting NetVanta it will stop working correctly after 4-6 hours or can go as long as 18 hours. 

Again, I see no obvious signs of the Netvanta acting up.  Interfaces all appear good, able to login via network, etc.

There are three lines that are included in a trunk group.  They are setup for Linear Cycle.

When this problem arises I see that all enabled fxo interfaces are "On Hook".  Is that what you are asking?  Sorry I'm new to these devices. 

Phone company came out and replaced some of their equipment down the road.  They swapped a card out and moved one line just to rule out some issues they thought may be due to weather, etc.  They tested all lines, while system was working, and found no major issues.

[jayh]

"On hook" means that the interface is idle, waiting to accept or place calls. Just like an old-fashioned POTS line with the receiver hung up "on the hook".

A busy signal when dialing in from outside in this condition suggests an external short on the carrier's gear. If they've made some fixes, hopefully that has solved your problem. Please do take the time to verify proper grounding as this can cause strange issues and possibly even equipment damage if there are electrical storms in the area.

[b_stimp]

Thanks for your help.

Update with additional information -

I checked Netvanta and there is no ground connected to the post on the back of unit.  (Device was install over 5 years ago and I'm guessing has never had a proper ground since then).  So that is one issue and something to add to my to-do list.

Lines went down again so I finally got a phone set and connected it to the the phone panel on wall.  When plugged into "Line 1" it was dead, no signal or dial tone at all.  When plugged into "Line 2" it had dialtone and I could successfully call out from there to my cell phone.

Phone switch still had no new errors or logging info that jumped out as abnormal to me.  Internal connections and extension to extension calls still worked.   Power-cycled Netvanta and lines came back on with dial tone.  Went almost 4 days without the problem and then it returned again this morning.

So somewhere there is a disconnect with that first line, which I'm guessing takes the trunk and hunt group basically offline since Line 1 is dead signal.

As to what initiates that dead signal, I'm unsure still...

[jayh]

b_stimp wrote:

Lines went down again so I finally got a phone set and connected it to the the phone panel on wall.  When plugged into "Line 1" it was dead, no signal or dial tone at all.  When plugged into "Line 2" it had dialtone and I could successfully call out from there to my cell phone.

Phone switch still had no new errors or logging info that jumped out as abnormal to me.  Internal connections and extension to extension calls still worked.   Power-cycled Netvanta and lines came back on with dial tone.  Went almost 4 days without the problem and then it returned again this morning.

So somewhere there is a disconnect with that first line, which I'm guessing takes the trunk and hunt group basically offline since Line 1 is dead signal.

As to what initiates that dead signal, I'm unsure still...

If you are able to repeat that, when you test with your test phone, do so at the closest point to where the lines come in from the street. Disconnect the wires going to the Netvanta completely. Sometimes there is a plug-and-jack arrangement right at the entrance for this purpose, other times there are bridging clips across a punchdown block that you can pull. See if there is dialtone and the ability to make and receive calls then.

The purpose of the test is to verify if the problem still exists when all of the inside wiring and the Netvanta are out of the loop. If still no dialtone then problem is with telco. If it then works, there's an issue with the inside wiring or the Netvanta.

[Anonymous]

Brett, were you able to get a test with the 7100 out of the loop? Thanks

Jay

[b_stimp]

It has been solid for 3-4 days.

Here is what I did after the last time it went dead--

Firmware was way out of date.  To the point that the support portal didn't even have the necessary update for me to jump to the newer versions.

Support provided me with a link to download, that way I did two firmware upgrades and am now on R11.4.5

Since then I haven't seen the problem return.  I've had it go a few days without problems before, so I'm not holding my breath just yet.

It should be noted that several days back I also requested the phone company to monitor the line that was having issues, I haven't heard back from them so unsure if they found or did anything at all.

If it does go dead again I will disconnect all lines from Adtran and test with dummy set again.

Appreciate all the help on Jay!