fxo problems and very very tired

[a.gooding]

hi,

posted a few topics a while back on an fxo disconnect issue im having with all my IPT sites. ALL.

i opened a case created voice classes etc etc but no resolution. i called the carrier, i cannot convert direct lines to ground start etc etc. basically, im out of ideas.

here is a run down on the scenario

routers -2801 voice 12.3T and vic2-4fxo as well as 2600 NM-2v with vic-2fxo

using mgcp

lines coming into FXO ports- direct lines.

all sites are connecting to a central auto attendant

PROBLEM

if i call in an call is established i have no issue

if i call in and hang up at any time before call is established, the port hangs. some sites will disconnect in 20 seconds and some sites will disconnect in 5 mins.

we have one local carrier only and switch is dms100

the only breakthrough ive had and its totally by accident is that i have 2 lines inhouse. the same router works perfect i mean perfect with one and i have the exisiting issue with the other line. i checked and both lines are adsl lines.i really dont understand and i really need to fix this issue

help!!!!!!!!!! ;)

[oj88]

I'm not sure how far you have gone to ressolve this. I use voice classes on all of my installations and they worked flawlessly (almost). Calls are terminated within 5 to 8 seconds after the far-end telephone has been placed on-hook. If you did configured voice classes, are you sure you're detecting the correct tone frequency(ies) and cadence?

Here's an excerpt of the configuration I use:

!

voice class custom-cptone TelcoA

dualtone disconnect

frequency 425

cadence 750 750

!

voice class custom-cptone TelcoB

dualtone disconnect

frequency 480 620

cadence 500 500

!

voice-port 0/0

translate calling 1

input gain 9

timeouts call-disconnect 1

timeouts wait-release 1

connection plar 171

station-id name TelcoA-01

supervisory disconnect dualtone mid-call

supervisory custom-cptone TelcoA

!

voice-port 0/1

translate calling 1

input gain 9

timeouts call-disconnect 1

timeouts wait-release 1

connection plar 172

station-id name TelcoA-02

supervisory disconnect dualtone mid-call

supervisory custom-cptone TelcoA

!

voice-port 1/0

translate calling 1

input gain 9

timeouts call-disconnect 1

timeouts wait-release 1

connection plar 175

station-id name TelcoB-01

supervisory disconnect dualtone mid-call

supervisory custom-cptone TelcoB

!

voice-port 1/1

translate calling 1

input gain 9

timeouts call-disconnect 1

timeouts wait-release 1

connection plar 176

station-id name TelcoB-02

supervisory disconnect dualtone mid-call

supervisory custom-cptone TelcoB

!

TelcoA's busy tone uses a single frequency of 425Hz and a cadence of 750ms (ON) and 750ms (OFF) repeating.

TelcoB's busy tone uses dual-tone frequencies consisting of 480 and 620 Hz (played simultaneously) with a cadence of 500ms (ON) and 500ms (OFF) repeating.

Here's what I did to figure this out:

1. Check the standard call progress tones in use in your country. Some of the common ones are (in Hz) 480 & 620, 400, 420, etc. Some examples can be found here: http://www.cisco.com/univercd/cc/td/doc/product/tel_pswt/vco_prod/sup_call/sup04.htm#xtocid4 You should lookup the specific tones that are in use in your country or call up your telco and ask them for it.

2. You'll need a tone generator. A software version can be found at http://www.nch.com.au/action/tnsetup.exe

3. Next, remove the line that's normally connected to the FXO port and insert it in standard analog handset ("test handset").

4. Using another phone, call up the number to ring the test handset and pick it up. Confirm that you are connected and you can hear your voice on the other handset and vice versa.

5. Put the calling phone on-hook and immediately listen at the test handset for a busy tone. The busy tone is your key to make voice classes work.

6. If you have done your research on call progress/supervisory tones specific for your country, use that information to setup the tone generator. You should then be able to compare the tone you're getting from the test handset with the tone produced by the tone generator. Try the most common tones listed above first.

7. Once you've determined the exact tone that your telco is providing, it's time to work on the cadence. In my country, tones are patterned from North American standards, and the busy tone cadence is set at 500ms ON and 500ms OFF, repeating.

8. After figuring out the cadence, make a voice class similar to the one I made above, substituting your own values for frequency and cadence. If you have more than one teclos in use, you may need to configure different voice classes if they give off different busy tone frequencies and/or cadence, like I did.

Good luck!

[a.gooding]

hey thanks a lot for the reply

appreciate it, these are the specs for tones of my country trinidad

ive configured voice classes already and the cadence. it makes an improvement definitely but not at all sites. all sites using same router ios and cards..some disconnect at 8 -18 seconds and some doesnt at all...the only thing i didnt do as in your config is set the input gain. here is a my first covoice class custom-cptone TEST1

dualtone busy

frequency 480 620

cadence 500 500

dualtone reorder

frequency 480 620

cadence 200 300

dualtone disconnect

frequency 400 631

cadence 300 200

the second config put the cadence on the busy tone as 300 200

[oj88]

Hi, try using the same parameters configured for busy tones on dualtone disconnect.

dualtone disconnect

frequency 480 620

cadence 500 500

A few other causes why this problem persists is because different telcos use different tone standards, even within the same country. In some cases, which I experiance a lot, is that even the same telco will sometimes use differing standards on different regions of their franchise area.

Nothing beats actually listening in at the tones yourself and with the help of the tone gen.

Have you tried battery-reversal?

[a.gooding]

ive tried battery reversal...at some sites i need to disable battery reversal for it to function. at other i need to leave it on. and for the real problem sites, no matter what i do it hangs. i also tried the frequencies for thedualtone disconnect but no dice. Note that we only have one carrier in Trinidad and Tobago and also they all use DMS100 switches. check this out, i have at one site, four lines coming in. they all terminate at the same point from the carrier point of view. but 3 disconnects ater 12 sec, and one doesnt at all.

then i have some sites that will disconnect fine (8-16 secs). but then other sites, that terminate to the same switch doesnt. as i said, i have two lines inhouse doing tests and they both terminate at the same switch. the difference between the test lines and the actual site lines is that the test lines are also ADSL. but, one of the test lines gives the same disconnect issue while the other disconnects almost immediately.im waiting for a tech at the carrier to call me but im sure i wouldnt get any info. is there anything that the carrier can do for me?..ill ask them about the tones for each location but other than that i dont know. i spoke to them already about converting to Ground Start and they say thats only done to trunk lines, not normal PSTN direct lines.

[oj88]

Looks like you need to play around with the dualtone detection parameters. It allows you to fine tune the tone detection process. This could be helpful if the some noise is present in the lines and the FXO cards are having a tough time detecting the tones:

R01(config)#voice class dualtone-detect-params 1

R01(cfg-dual-detect)#?

VOICECLASS configuration commands:

cadence-variation Cadence variation allowed

exit Exit from voice class configuration mode

freq-max-delay Timing difference between two frequencies

freq-max-deviation Maximum frequency deviation allowed for each frequency

freq-max-power Absolute value of upper limit for tone power per

frequency

freq-min-power Absolute value of lower limit for tone power per

frequency

freq-power-twist The difference between the power of two frequencies

help Description of the interactive help system

no Negate a command or set its defaults

[a.gooding]

yup.......tired that as well, however, i was kinda shooting in the dark since i have no clue on how to attain the values for the freq parameters...these are the two parameters that cisco told me to try

voice class dualtone-detect-params 100

freq-max-deviation 50

freq-min-power 35

!

voice class dualtone-detect-params 1

freq-min-power 23

freq-power-twist 5

obvoisuly..that didnt work........but then again, remember i really was just playing with numbers there...

[a.gooding]

here is a question though..can a carrier enable Central Office Disconnect on a residential line?...i was told that it can only be done on trunk lines but now im hearing from someone else that it can be done and that solves all the issues...im trying to get someone at the telcom service to answer my question but thats like calling dead air..

[oj88]

I wouldn't know, I haven't tried asking. I anticipate a lot of red tape doing so. :)

But it would be great if they can enable power denial supervision on ordinary analog lines.

[maharris]

Well, I work for a phone company, but on the data side, so I don' tknow all the ins and outs, but I do know that a lot of what you can order in this country has to do with what has been published in the tariffs. Service is very regulated, not to drive us crazy but to make sure that everything is absolutely fair, and the providers can make a profit but not too much, etc. So, what exactly is included in a service is described in painful detail, and also depends on what kind of facility you are connected to, or could connect to in the local office. You proably can't get many extra options, or quality enhancements, on a line that is a residential class, but they might be able to put in your order to change your service, and add features. They may or may not have to move where you terminate in the office. You will certainly have to pay for the change order, and maybe extra each month for the new service class. It is also possible that the office you are near can not provide what you are asking for, but they should at least be able to tell you that, eventually. It would be nice if they could look it it up quick, but ordering can be horribly complicated, and you have to find someone who understands exactly what you are looking for first, and it may not be the first person you call at the toll free number. The phone company here has what they call USOCs, Universal Service Order Codes, that describe all the possibilities. I think there must be thousands of them, for every possible combination. Good luck!

Mary Beth

[a.gooding]

Thanks a lot for all the replies it has helped me so much. i called in a favour from a friend that works at the carrier. we checked the both lines to see what the difference was. the one that works fine has the COD feature enabled. the other does not. the COD feature is only available for trunks. he said to make the request and they will change all the lines to trunks. its a matter of software configuration as well as an extra charge but it will be totally transparent from branch office point of view. so thats it, from now on, anything im doing with FXO im doing with trunk lines..:)...

[a.gooding]

OK.... it worked...disconnects immediately at "most sites"....you still need to enable supervisory disconnect dualtone and configure timeouts.also, importantly, disable battery reversal..but it works, all the sites that didnt disconnect at all are now disconnecting immediately.