Outbound calls to some cell phones goes directly to their voicemail

[Danny Mainprize]

This is a new one on me.  We just finished updating our dialing plans and everything and ever since there are some cell phone numbers that if I call from my VoIP phone to the cell phone, it goes directly to their voicemail.  If I call the same number from my cell phone to their cell phone it rings just fine.  Is there some weird digit sending combination that I am missing that is causing this behaviour?  This is on CUCM 12.5 and using a Cisco 4321 router.

[Kathy N.]

We are actually working on a similar issue but it appears to be a routing issue with our provider, Lumen.  They made a change to remove a 3rd party route and we think it resolved our issue but we're still verifying.

[Maren Mahoney]

We also use Lumen and also have weird 'this number works and that one doesn't' issues with them.

You can look at what you are sending to the provider for calls that work versus calls that don't, but I suspect you already have and have noted that you are sending the same digit patterns in both cases. If so, I agree with @Kathy N. that you are looking at a provider issue.

Maren

[Nithin Eluvathingal]

This is something which you must work with ISP. I dont fell this as your configuration issues.

You can verify the digits sent to ISP collecting debugs from Voice Gateway.