FXO with Caller ID

[JustForVoice_2]

Hi everybody,

I do not have a specific problem to discuss, I have a general problem. I opened this discussion to exchange and share experiences with other members.

If you have some document about Caller ID with FXO or if you opened a TAC case with Cisco and they asked about some debugs or if you know the required parameters that we should set to get the Caller ID just share your knowledge here.

As I said I do not have specific problem I just need to build a solid backgrouond to solve this type of problems. so it is you chance to add 5 points to your earned points.

[clileikis]

Hi there,

Check out the following Caller ID Document:

Configuring FXS and FXO Voice Ports to Support Caller ID

http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/cisco_ios_voice_configuration_library_glossary/vclclid.html#wp1077886

HTH,

Chris

[JustForVoice_2]

Hi,

thank you for posting, but as you know many times you are configuring these commands but sitll no caller ID. many times I tried to add these commands:

caller-id enable

caller-id alerting dsp-pre-alloc

but still no caller ID.

[JustForVoice_2]

Am I the only one how faced this problem?

No body has some information to share?

No body needs +5 points

[acampbell]

Hi,

Here in the UK CLI delivery is chargeable on POTS lines.

One you pay for the service it gets turned on at the Telephone Exchange (CO).

Not sure about your lines locations.

Any way you have the correct cofig for FXO :-

caller-id enable

caller-id alerting dsp-pre-alloc

You can try using :-

debug vpm signal

A good explanation of what to look for is at the bottom of this link in the

troubleshooting section - 
Debugs for an FXO Port Receiving Caller ID Correctly
http://www.cisco.com/en/US/tech/tk652/tk653/technologies_configuration_example09186a00800a9a49.shtml#tsprocedure
HTH
Alex

[JustForVoice_2]

Thank you for sharing,

Even in my country the same, you have to pay for the service and once you paid they will activate the service.

but some times my customer has paid for the service and Telco has activated the service but the router is not able to detect the CLI. and if you tried to use debug vpm signal you will not find the CLI. but if you connect an analog phone with display you can see the caller ID.

to overcome this problem we are trying to change some parameters under the voice-port like:

cptone and battery-reversal

but it is not allowys help?

[tonypearce1]

I have CID issues also. I've been trying small things methodically to resolve, with the help from others on this forum. It is mostly working now but sometimes it stops. The CID unit which is separate from the system always displays the caller ID correctly.

My next test is to try impedence matching. Have you tried this? What country are you in?

[Aaron Harrison]

Hi Folks

Basically there are various ways of signalling CLI over an FXO which are all kind of tacked-on functions. They work differently depening on what country you are in, and I've no doubt where you don't have a British Telecom style monopoly there are probably variations between countries.

So there are a lot of commands for this - the best way (as with most things) would be to find out how it *should* work in your country/telecom provider, and then configure the gateway to match.

For example in the UK BT like to use a short line disconnect period to signal a far-end hangup, requiring timeouts sup-disconnect 85 on the port - this used to be a hidden command when I first did an FXO. Not helpful, and I'm not sure how I would have found it without TAC/this forum (can't remember where I found it to be honest!!).

So with caller-id, there are lots of commands - BT supply CLI before the phone starts ringing, which is why we need the 'dsp-pre-alloc' command.  When Tony puts in cptone GB he gest some extra commands over what I last used, but this is probably because Cisco think they're needed for a GB FXO (they may be right, and it may be the case that  the extra stuff was deemed default in an earlier IOS and therefore didn't show up). I've not done an FXO in recent days, as we generally try as best we can to avoid them due to quality issues.

This doc lists a few of the commands and what they do : http://www.cisco.com/en/US/docs/ios/12_3/vvf_c/cisco_ios_voice_configuration_library_glossary/vclclid.html

e.g. line-reversal tells the router to interpret a short polarity reversal as notification that caller-id is going to be signallied now...

There's a little more in the IOS command references, this one for 12.4:

http://www.cisco.com/en/US/docs/ios/voice/command/reference/vr_c4.html

If it works, then stops working, and never recovers without config changes, it sounds a lot like a bug.

Generally if I'm installing an FXO I do the impedance matching tests, but you also need to back those up with some user tests - i.e. does the line sound better with the new impedance setting over what was default?? I don't think I've ever noticed it having any impact on the CLI reception, but since it's an analogue line carryingn some sort of modem type signalling to get the CLI data it stands to reason poor quality would affect it.

Regards

Aaron

[JustForVoice_2]

Thank you all for sharing,

Aaron,you talked about impedance matching test, could you please tell me about this more? you and Tony talked about impedance? is there any relation between CLI and Impedance?

If I envolved TAC in CLI are they able to help?

[tonypearce1]

Hi, I ran these impedence tests today http://www.cisco.com/en/US/tech/tk652/tk701/technologies_tech_note09186a0080477a06.shtml#thl

I found that the tests would not complete (failed), until I removed DSL filter and all other phone equipment from the line. I am wondering now if my CLI to the FXO is somehow affected because of the other equipment on the line, i.e. poor quality as Aaron says. But strangely my BT caller ID unit (which is quite old now, but used specifically for caller ID) always picks up the ID every time. I also notice that caller ID comes in first in my situation, then my POTS analog phone (separate from the CUCME) rings after, whilst sometimes my IP phones ring a little before the POTS line may be not allowing enough time for CID to come through. I'm not sure if this is true, I'm just trying to work out the specifics. I'm using Plar OPX for the above setup.

Depending on your country would depend on how the CID is transferred to you.

Aaron, in my case now it works the majority of the time. If left for a long period it stops working. But if you immediately place another call after the last into the system Caller ID works every time. Quite strange.

[acampbell]

Hi,

Just for additional information re BT/UK PSTN lines

Please see the following.

For info re line impedeance

http://www.sinet.bt.com/351v4p5.pdf

I reckon that on a Cisco router FXO we should be using COMPLEX3

For CLI lookat this

http://www.btwebworld.com/sinet/227v3p5.pdf

The CLI is delivered after the the alerting line reversal but before the 1st burst og ringing current.

It looks like on a router it can oly be

!

caller-id enable

caller-id alerting dsp-pre-alloc

!

Regards

Alex

[JustForVoice_2]

Hi Alex,

I am now trying to browse the links that you added.

In many countries I knew, we are facing FXO Caller ID problem. but the problem it is not per country it is inside each country

it depends on the CO in that area. some Telco are using many providers for their Telephone exchange and unfortunately each exchanged is configured with different parameters.

I faced some cases where 4FXO ports in the same card in the same router, 3 lines CLI working fine but 1 is not working and if you connect analog phone with caller ID it is working on that line. so what I should do

[JustForVoice_2]

Thank you Tony for sharing your experience

did you try to add the following command under FXO port:

caller-id alerting ring  X

X = 1, 2, or 3 just test the three values.

and it is better to shut and no shut after any change.

[tonypearce1]

Hi, yes I tried this but my provider issues caller ID before the ring, apparently.

I've tried caller ID alerting dsp-pre-allocate, and also with the "line reversal" command. It appears to me that my router or FXO kind of "goes to sleep" after a long period of time. Say if I do not receive a call for 2 hours, caller ID is not received on the FXO, but other analogue devices do receive it 100% every time. However, if I then receive another call 30 minutes later, caller ID is displayed.

Another thing I notice is my other analogue devices (caller ID display unit, analogue phone) have a 4-wire cable to the PSTN. When I plug their cable into my FXO, I cannot sieze the PSTN line to make an outgoing call, nor can the FXO detect ringing status. It's as if it is disconnected. Any ideas on this?

[tonypearce1]

Hi again all. I wanted to post back as I am now having some success with Caller ID. I raised a TAC case for my issue and the engineer took some captures and advised me to adjust the input gain so the router receives a better signal for Caller ID.

I've made the following change and the whole of today Caller ID has worked flawlessly.

voice-port 0/1/0

  input gain -6

I'm going to continue testing but before, I was easily able to reproduce the problem by not receiving a call for a few hours. Even after a near 24 hour wait I'm unable to reproduce. The default is "input gain 0" and the adjustment is in dB.

If anyone tries this please post your experiences?