The calling party could not hear the ring back tone

[Yangjp715]

Hi there,

The calling party could not hear the ring back from the called party with local call, the call will be answered after a few second. However the national and international calls work well. Is there anyone who can help me with that? The log file is attached.

Thanks in advance,

Eric

[hsood]

Hi,

From the debugs attached, it seems the telco is sending the call back to CUCM ip phone.

Do you have a H323 / SIP / MGCP connection with CUCM?

We get a Alerting pretty fine on the hair-pinned call.

Ideally, what needs to be checked further as to whether the gateway requested the CUCM to play that alerting message or not which depends on the protocol you are working with.

Regards,

Hitesh

[Yangjp715]

Hi Hitesh,

We have a h323 gateway in our London office. But national and international calls both work fine, only local call does not have ringback tone. What do we need to check from GW and CUCM?

Thanks,

Eric

[hsood]

Hi Eric,

If we have an H323 gateway, we should be seeing a H225 alerting message from the gateway to CUCM end and then CUCM should instruct the phone to play the ringback from the local cache.

Since, national and international work fine, it is highly unlikely that CUCM be at fault, it seems to be an issue possibly with the gateway.

Along with the debugs you ran, can you check the following debugs as well and see if you see the alerting message sent in both the working and non-working scenarios:

debug isdn q931

debug h225 asn1

[Yangjp715]

Hi Hitesh,

The log file is attached. The first two (02038026287 and 02031021948) are local calls which I could not hear the ring back tone.

Thanks,

Eric