sundance-communications.com/forum Forums TDM Business Telephone Systems NEC Telephones & Systems can't break dial tone

I installed more than 15 SV8300 pbxs.after about 3 months 3 of these pbxs got same fault:
all anlog extensions in these pbxs can't make any call. they get dial tone but when dailing any number they do NOT go. and users contiue to hear dial tone. rsetting the pbx solves the problem for some time but the fault keeps occuring again and again.
all pbx rooms are airconditioned and room temperature is around 20 C. degree.
thanks for your good care.

Have you looked into similarities between the 3 and differences with the other 12 such as software versions, lot numbers of the blades used?

software version for all 15 sites is "SC-4000 F2-0000.05.00". they all have: 3 CO cards,1 PRI card, 4 DLC cards, and 5 (16) lines LC cards . note: all Dterms work perfectly,

Haven't played with the 8300 but basically you're describing a register problem. I would be finding out where the register is located and changing that card!

R4+Z


PBT registers are located on the cpu card.
I did change the cpu but that did not solve my problem.

Did you escalate with NTAC? Send them a copy of the database(s)?

Latest software is 7.0, perhaps try upgrading one of the sites?

SC-4081 J1-0001.05

D

On the IPS there used to be an issue like this. It could usually be resolved by changing the port settings to give a longer or shorter DTMF tone duration.

I've also seen this with defective analog phones, but that wouldn't explain it working after a reset.

I am not sure what they call it on an SV8300 but in Avaya systems there are touchtone receivers that are a system resource, so the system can interpret the tones from analog devices. On a digital set they are not used because the data stream between the phone and the system tells the processor what is being pressed. When they don't work the system is "deaf" to touchtones.

On the SV8100 there is a program for these resources called "DTMF and dial tone circuit setup". They can be set for use by analog stations, trunks, or both. Then norm is to change the setting to both.

Now I have no clue about the SV8300 and how it allocates resources but you may want to search the manual and see if "DTMF and dial tone circuit setup" is in there.

good news:
Upgrade one of these faulty pbxs to "SC-4081 J1-0002.04.00" and no more faults are occurring....PBX is under observations for a while.
thanks to all of you and to doghart who suggested the upgrade.