"You've dialed out to a different phone" message on Lync client

Problem:

When you dial the Lync meeting using the option "Call me at:" and choose pre-defined phone number from the drop-down menu, you may get the following message "You've dialed out to a different phone" on the Lync client and call does not go through.

Also, you may notice that the number that is being prompted to dial is not normalized or normalized incorrectly.  In my case it was shown as +XXXXXXXXXX.

Cause:

Normalization rules for Lync Address Book do not work properly. (You also see event id 21034 in the Lync event log on Lync front end server: 

"One or more phone numbers failed to normalize.

998 total numbers failed to normalize. They are listed in the text file: '\\your_lync_share\1-WebServices-11\ABFiles\00000000-0000-0000-0000-000000000000\00000000-0000-0000-0000-000000000000\Invalid_AD_Phone_Numbers.txt'

Resolution:

Correction of normalization rules file.  It can be found in all WebServices directories on your_lync_share.  In my case, I had 3 WebServices folders:

1-WebServices-1

1-WebServices-9

1-WebServices-11

File name:

Company_Phone_Number_Normalization_Rules.txt

In my case:

Following rule:

\+?[\s()\-\./]*1?[\s()\-\./]*\(?\s*(\d\d\d)\s*\)?[\s()\-\./]*(\d\d\d)[\s()\-\./]*(\d\d\d\d)[\s]*
+1$1$2$3

Needed to be changed to following (we have a leading “8” in our phone system):

\+?[\s()\-\./]*1?[\s()\-\./]*\(?\s*(\d\d\d)\s*\)?[\s()\-\./]*(\d\d\d)[\s()\-\./]*(\d\d\d\d)[\s]*
81$1$2$3

(Since I was on it I added one more rule:

(\d{4})[\s]*

$1

To accommodate AD records that have extension instead of full phone number)