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FXO Disconnect Problem ;)

rgeorgiou
Level 1
Level 1

Hi guys,

I have the classic disconnect problem and with all the terrible bytes on the internet have be unable to find the appropriate solution.

If i ring the PSTN line connected to the FXO port i have PLAR directing the call to 1000 my Reception phone. Im in Australia and the cptone is set to AU.

I have tried different voice class's but i am not getting anywhere. i recorded the disconnect tone from CIPC and i believe the frequency is 400, and the cadence is 380. I inserted a custom class and linked i to my voice port 1/1/0 but with no joy.....

Anyone got any ideas.....

Please advise

2 Accepted Solutions

Accepted Solutions

under the voice-port, add these commands -

timeouts call-disconnect 3

timeouts wait-release 3

This should drop the time to drop the call down to about 5-6 seconds after the tones are initially detected

Don't use any value lower than this as the call disconnection may become unreliable.

View solution in original post

I'm not sure what they mean by a 'known problem'. Loop start operation has been around in one way or another for over a hundred years, and any specific problems would have been sorted out a long time ago. It was designed for connecting telephone handsets and the idea has always been that the people say 'goodbye' and then physically hang up towards the network. In this sense the disconnect supervision is controlled by the people on the phone call. The telephone network NEVER hangs up towards the users - it signals the far end disconnect by battery reversal or disconnect tones.

There is no reason why this should not work with disconnect tones. The next suggestion would be to get a wireshark trace of the call and then hang up the PSTN side. This will capture all the call signaling and the audio from the gateway

Groundstart is unheard of outside of North America. Telstra/Optus can supply an analogue loopstart trunk or ISDN BRI for low density connections.

View solution in original post

24 Replies 24

paolo bevilacqua
Hall of Fame
Hall of Fame

pcameron
Cisco Employee
Cisco Employee

As you have noted, this is a single tone of 400 hz, cadence is 380 msec on, 380 msec off.

Kind of weird - generally Telsra uses 425 hz, 350 on, 350 off. Is this connected to a 'normal' PSTN line or something else ?

Please paste your full config and we can check out exactly how you have set this up.

voice-port 1/1/0

supervisory custom-cptone DISCONNECT

cptone AU

connection plar 4000

voice calss custom-cptone DISCONNECT

dualtone disconnect

frequency 425

cadence 350 350

or

voice calss custom-cptone DISCONNECT

dualtone disconnect

frequency 400

cadence 380 380

or

voice calss custom-cptone DISCONNECT

dualtone disconnect

frequency 425

cadence 375 375

above is what i have tried.... but no luck

Try this:

voice class dualtone-detect-params 1

freq-max-power 0

voice class custom-cptone TEST

dualtone disconnect

frequency 400

cadence 380 380 380

voice-port 0/3/2

supervisory disconnect dualtone mid-call

supervisory custom-cptone TEST

supervisory dualtone-detect-params 1

hth,

nick

tried this, still happening...... grr

voice class dualtone-detect-params 1

freq-max-power 0

voice class custom-cptone TEST

dualtone disconnect

frequency 400

cadence 380 380 380

voice-port 1/1/0

supervisory disconnect dualtone mid-call

supervisory custom-cptone TEST

supervisory dualtone-detect-params 1

Try adding

voice-port 1/1/0

timeouts wait-release 1

Forgot that one..

-nick

This <> just work :-)

You haven't mentiond IOS versions, but three is a DSP bug (CSCsq91055) that causes problems with supervisory disconnect tones in later (12.4.20T+) releases.

Try loading IOS version 12.4.20T3 , or even the very latest version of 12.4.15T (an oldie but a goodie release!)

What platform are you running this on ?

I configured tone based supervision for the first time, and observed it take 30 second to drop the line, although the disconnect tone is detected immediately. I have the recommended timeouts setting under voice-port.

Anybody know of a mean to shorten the 30 secs ?

under the voice-port, add these commands -

timeouts call-disconnect 3

timeouts wait-release 3

This should drop the time to drop the call down to about 5-6 seconds after the tones are initially detected

Don't use any value lower than this as the call disconnection may become unreliable.

This may be a version specific thing, but from what I've tested once the router decides to disconnect it will wait the designated time, and hang up. This in regards to the wait-release timer.

It sounds like from here:

http://www.cisco.com/en/US/docs/ios/voice/command/reference/vr_t2.html#wp1640487

You can probably set the call-disconnect to something like 5-10 seconds, which is how long a call is connected before the router starts listening for disconnect tones. This is to prevent the router from disconnecting on something like ringtone.

I would say you should be fine setting the wait-release to 1 second, because by the time this timer is activated the router has already made the decision to disconnect the call. It's just a matter of how long of a tone you want the user to hear before it's disconnected.

-nick

I've seen this for a few scenarios:

This bug can do things like that: CSCsu68373

As well, are you using 'cadence continuous' by any chance? There are some intricacies with the way that works that could cause that.

-nick

tried it still not luck...

tried it still not luck...

timeouts call-disconnect 3

timeouts wait-release 3

IOS is c3640-a3js-mz.124.25

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