ht-503 -- PSTN disconnect does not disconnect FXO line

[sims]

my setup: HT-503. one PSTN line (in India). two SIP accounts - 1 FXS and 1 FXO (both from US based service providers).

the problem: i call PSTN number and receve FXO dialtone. dial a US number. number rings. then i disconnect from the line. HT-503 does not disconnect FXO originated call.

it was suggested in another thread that i sniff to see if HT-503 receives the signal. i do not know what software to use and how to use it to sniff

any help would be greatly appreciated. thanks!

[MichaelJ]

Hi,

This week I deployed a Grandstream PBX in the Caribbean on the island of Nevis. I also ran into a similar FXO problem where the local PSTN line takes about 60-120 seconds to disconnect. I believe that the problem is with the style of disconnect that the local phone company is expecting.

If you cannot get the exact details from the phone company supplying the phone line, then you will probably have to test each variation of the PSTN disconnect settings. Unfortunately you will also have to re-boot every time so this process will be disruptive and will take a while.

Also I am trying to deploy using “Cable & Wireless” phone lines and they are not going to provide me with any technical specifications so I will be testing every scenario to see what makes the phone line hang-up the fastest.

Good luck..!
MichaelJ

[sims]

michaelj, that sounds like what i might have to do. but what settings do i experiment with? i do not even know that

thanks!

[MichaelJ]

sims,

First make sure that you have the latest firmware update. They have made many enhancements in the last release.

Then look under Trunk/Phone lines and under FXO Terminal

You will see some options there such as
Enable Current Disconnect No Yes Current Disconnect Threshold(ms) (60-10000, default 100) Enable Tone Disconnect No Yes Polarity Reversal Disconnect No Yes AC Terminal Impedance Scheme Country Model AC Terminal Impedance USA & Canada Austria Austria & New Zealand Belgium Finland France Germany Greece Italy Japan Norway Spain Sweden UK China

Here you will be able to try different settings until you (hopefully) match the required setting.

If all of this fails then that would indicate a bug on the Grandstream unit itself..!

Keep me posted if you find the solution and I will do the same for you.

Thanks,
MichaelJ

[sims]

i tried to experiment some but no success yet.

so i have now put in a support request to grandstream's support desk. it is Sunday today. i hope to hear from them by Monday evening.

and will post any solution i find.

cheers.

[xylaur]

I believe there is a problem with the HT-503 firmware as I have encountered a similar problem.

My HT-503 forwards all calls to Asterisk. If nobody answers it goes into voice mail and if the caller terminates the call at that moment the FXO will not disconnect. The same thing happens if the caller terminates the voice message by hanging up instead of pressing the "#" key.

It maybe an Asterisk problem but somehow I lean more to a firmware problem with the HT-503.