Delay in dialing International Calls

[a.gooding]

Guys,

im having a slight issue with international calls and a delay or rather lack of ringback.

Local Calls - Fine and am hearing call back

International Calls - No ringback for the first 12 seconds then ringback is heard.

Gateway - H323

Dial Pattern - i have tried narrowing down the pattern to the actual test number im trying to dial with the same result. i have also placed progress indicators without any reduction in the delay.

If i convert the gateway to MGCP i get a postive response, 2-3 seconds before ringback. However, MGCP is a bit unstable and it was up for a while, then dropped. only way i could get it back up was to reboot the router then it would stay up again for maybe an hour or so then drop again.

id like to get the ringback using H323.

Ive also changed the value under the CCM service parameter to use ANN for local ringback but still nothing.

any ideas on how i might be able to proceed?

Below is the final config we setup

[Craig Cooper]

Hi,

It sounds more like you might be encountering an Inter-digit timeout issue of some kind.   If you telnet to the H.323 gateway, and run a "debug isdn q931", is the SETUP actually being sent out to the PSTN straight away, or is it only going out after the initial 12 seconds?

If you then turn on "debug voip ccapi inout", is the H.323 setup even arriving at the H.323 gateway until the 12 seconds has expired?

If not, you might be best looking back at CUCM... If you're only using a ! route pattern, for international calls, then you're probably hitting an inter-digit timeout.   Does it go through straight away if you dial the "#" at the end?

The only way to immediately send through calls to some countries with variable length dial plans is often to either wait the interdigit timeout, have a complete plan for every country that exists (fairly implausible), or to dial the # at the end.   For example, New Zealand has some mobile phones with 11 digits including the country code (e.g. +6421xxxxxxx) and others with 10 digits (e.g. +6421xxxxxx).   Both are equally valid, but if you can't narrow it down further, e.g. with +64211xxxxxx versus +64215xxxxx, then you will need to wait the inter-digit timeout.

For a better understanding of dial plans, please see the following, now quite old document:

http://www.cisco.com/en/US/products/sw/voicesw/ps556/products_tech_note09186a00800949f0.shtml

Kind regards,

Craig

[a.gooding]

Craig,

thanks for the input. im fairly certain that the interdigit timeout isnt the issue though.

if i place a call from the phone and look at a debug voice ccapi inout or show voice call stat i see the call immediately.

ive just logged in and collected some information

isdn q931 , ccapi inout and also a show voice call stat and port summary. the voice call stat appears almost immediately on the router once i dial the number on the cisco phone.

ive named the file with the called and calling numbers as well.

tell me if it still looks like a digit timeout issue so i can address on that side. i personally think its a carrier delay so im looking to see if we can generate a local ringback tone which i assumed the PIs were for.

PS typo on the file, the cisco extension is 4076

[a.gooding]

This is where im seeing the issue i think. thats a 10 second delay. 601186: Dec 17 02:19:08.867 UTC: ISDN Se0/0/0:15 Q931: RX <- SETUP_ACK pd = 8  callref = 0x8A54 Channel ID i = 0xA9839F Exclusive, Channel 31 601187: Dec 17 02:19:18.887 UTC: ISDN Se0/0/0:15 Q931: RX <- CALL_PROC pd = 8  callref = 0x8A54 601188: Dec 17 02:19:18.887 UTC: //9088/809BEA8CFA10/CCAPI/cc_api_call_proceeding:

[Craig Cooper]

Yes, 10 seconds between the outbound SETUP and the CALL_PROC, then another 2 seconds for the PROGRESS from the telco seems excessive.   Does this change if you use a Plan of ISDN and a Type of International?

[Craig Cooper]

Is this connected directly to the telco, or going via a legacy PBX (by any chance)?

Kind regards,

Craig

[a.gooding]

i havent adjusted any plan ISDN or anything of that sort.

this is connected directly to the telco equipment.

The telco is running an E1 over an mini-link (Cellular). I have tried getting information and based on some round around tests (Cell to Cell) im seeing a setup time of around 8 Seconds (i know). so My CUCM takes that 8 sec, then it needs a few seconds so i gather thats where the combined delay comes in.

thats why i came up with trying to figure out how to get a "fake" ringback going.

again, i tried the MGCP and i got the ringback down to maybe 1-3 seconds which is great. for whatever reason i just dont like MGCP and it proved unstable here as well since it went down a couple of times.

by the way, appreciate the responses, thanks

[a.gooding]

Just an update

issue was resolved by issuing the command  "isdn sending-complete". Call progresses almost immediately now.

thanks as always to TAC.

that was way too basic to miss though