Unable to callforward to an external number with a route pattern using a called party transform mask

[GuardguyMO]

I have CUCM 8.6. I have a DID built as a route pattern that has the Called Party Transform Mask set to an extension that is shared by 33 telephones. Only one of these phones this number is on is used as the primary key and the other 32 phones have it as a secondary key.

In the evening the phone with the primary key call forwards all his phone to an on-call Blackberry that provides 24 hour coverage. This Blackberry is a local number so the call forward is access code and 7-digits.

If I call the DID the call goes through to the 33 extensions when not call forwarded to an external number.
If I call forward all the extension to another extension the call goes through.

When we call forward the extension to the Blackberry it will give a short ring and the Blackberry shows a missed called. It does this two times and shows two missed calls every time the DID is dialed. The caller that is dialing the number receives a busy signal. There is about a 20 second delay until you get the busy signal.

Does anyone have any suggestions on this issue?

 

[GuardguyMO]

I have built a test phone with a DID as the primary number "not" using a route pattern with a transform mask and the call forward all works fine (just as I thought that it would).

Does anyone know why the transform mask would not work only when forwarded to an external number?

I am sure you are asking, the reason that I am not putting the DID on these phones is:
1. It is on 33 telephones for starters
2. It is a disjointed number (3xxxx), what I mean is it is not part of "their" dialplan (16xxx).

 

[gnrslash4life]

I would start by running debugs on the gateway to see what is being sent out as caller id. Might be the culprit and the telco is confused.

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