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Community Member

H323 signaling over voip dial-peer?

Hi I have this scenario:


I when i try to call outside to the PSTN with an analog phone on the vg224 there is no signal tone (0T). I can call to the internal extensions with no problem. I think that this may be a signaling problem but i don't know hot to configure it on the dial peer..

Dial-peer on the CCME side:

dial-peer voice 2000 voip

destination-pattern 200[1-9]

session target ipv4:

codec g711alaw

fax nsf 000000

fax protocol cisco

no vad


dial-peer voice 100 pots

preference 1

incoming called-number .

destination-pattern 0T


port 0/0:15

Dial-peer on the Vg224 side:

dial-peer voice 11 voip

destination-pattern 0T

session target ipv4:

codec g711alaw

fax nsf 000000

fax protocol cisco

no vad

Community Member

Re: H323 signaling over voip dial-peer?

if you mean ringback tone, enable this command under pots dial-peer config

progress_ind alert enable

Let me know if this helps...


Satish K

Community Member

Re: H323 signaling over voip dial-peer?

Further explanation of "progress_ind alert enable 8"

No Ringback Tone on VoIP Outbound Calls from Cisco CallManager (or Third Party Device) through Cisco IOS Gateway



A user makes an outbound call from an IP phone to PSTN through an IOS gateway/router and does not hear a ringback tone.

Problem Description

In this situation, the originating device expects in-band ringback tones. However, either of these can possibly be happening:

The PSTN/switch does not provide the ringback tone.

The Cisco IOS router/gateway does not cut through the audio to the originating device.

If the PSTN provides in-band ringback, and the Q.931 alert message does not provide a PI that indicates that there is in-band information, the gateway does not cut through the audio until the call is connected.


Follow one of these solutions :

1. Ringback tones must come from the PSTN for trunk circuits in this situation. There are two dial-peer subcommands which can help. On the IOS router/gateway under the outgoing voice dial-peer # pots, configure the command progress_ind alert enable 8.

This command presents the Q.931 alert message to the software on the router/gateway as if the alert message had a PI of 8 and cut through the audio path.

Note: The progress_ind alert and the progress_ind setup commands are hidden in some versions of Cisco IOS Software and may not be visible within the help parser. However, if the progress_ind progress command is available in the help parser, these commands are also available and can be entered into the dial peer in their entirety. These commands subsequently appear in the running configuration.

2. If the previous command does not solve the problem, in Cisco IOS Software Releases from 12.2(1) to 12.2(2)T and later, configure the command progress_ind setup enable 3 under the voice dial-peer # pot configuration. This command causes the gateway to send a PI with a value of 3 in the ISDN Setup message. This indicates to the PSTN/PBX that the originating device is a non-ISDN device and in-band information needs to be presented. It is recommended that this command be used in conjunction with the command progress_ind alert enable 8.

3. If the PSTN device is not able to generate ringback in-band (for example an ISDN phone directly connected to a BRI port on the gateway), the gateway can be configured to generate ringback on the IP call leg by configuring the tone ringback alert-no-pi command on the dial-peer voice # pots. When the ISDN alert is received with no PI present, the gateway generates the ringback in and includes a PI=0x8 in the H.225 alert message.

Community Member

Re: H323 signaling over voip dial-peer?

I find the solution, there is a wrong dial-peer that match before the "0T" dial peer. Seems that a dial peer with "...." have more preference than a "0T" when we dial a number begining with 0.

I don't need more parameters than i posted in the first post.

Many thanks

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