Most users understand that “to get an outside line”, they have to dial some number first – most commonly the digit 9, but sometimes other digits are used. When the user does that, they’re triggering Automatic Route Selection (ARS) functionality, which tells the phone system to automatically figure out how to route the digits that follow the access code.

Communication Manager (CM) permits administrators to assign one or two ARS feature access codes:

change feature-access-codes                                     Page   1 of  10
                               FEATURE ACCESS CODE (FAC)
    Auto Route Selection (ARS) - Access Code 1: 8     Access Code 2: 9

In the above example, ARS can be triggered by dialing either 8 or 9. That can be useful when, for example, users are migrated from many different phone systems onto a unified system, and some users are used to ARS digit 8, and others are used to ARS digit 9. That was the case when my employer deployed Communication Manager to many sites. The decision was made that both ARS digits should be permitted, as nobody was willing to spend the political capital required to retrain the users about that specific thing.

Time passed, and eventually I came to the conclusion that we were going to need to reclaim one digit or the other, so as to expand the available extensions in our dialplan (which were 4-digits in length). Digit 9 seems to be the most common ARS access code, and a very large quantity of our users already used it, so I chose it as the winner; digit 8 needed to be repurposed.

Announcements were made, months in advance, that users should begin using 9 as their ARS access code for all calls and faxes. Users were reminded again the week before, the day before, and the day of the change. Finally, I removed digit 8 as an ARS access code:

change feature-access-codes                                     Page   1 of  10
                               FEATURE ACCESS CODE (FAC)
    Auto Route Selection (ARS) - Access Code 1: 9     Access Code 2: 

And then I modified the dialplan analysis so that 8 became an extension rather than a feature-access-code.

display dialplan analysis                                       Page   2 of  12
                             DIAL PLAN ANALYSIS TABLE
                                   Location: all            Percent Full: 19

    Dialed   Total  Call     Dialed   Total  Call     Dialed   Total  Call
    String   Length Type     String   Length Type     String   Length Type
   8           1   ext
   9           1   fac

Knowing that our users were likely to continue attempting to use digit 8 for ARS access, I decided that we should play back an announcement, reminding them that digit 8 was no longer permitted, and that they should use 9 instead.

display announcement 61299

                       ANNOUNCEMENTS/AUDIO SOURCES

  Extension: 61299                           COR: 1
  Annc Name: ict-ext8                         TN: 1
  Annc Type: integrated                    Queue? y
Group/Board: G2
  Protected? n                              Rate: 64

The announcement was recorded substantially similar to “We’re sorry, your call could not be completed as dialed. If you are attempting to dial a party that is outside of the [organization name] central telephone system, please remember to first dial the number 9. Dialing the number 8 is no longer permitted as of Sunday, March 1, 2015. Thank you.”

I additionally wanted to ensure that we were playing a special information tone at the beginning of the message, so that any misconfigured (but reasonably intelligent) fax machine should immediately give up trying, rather than continue to try over and over. Thus the pre-existing SIT-VC announcement came into play:

display announcement 3442

                       ANNOUNCEMENTS/AUDIO SOURCES

  Extension: 3442                            COR: 1
  Annc Name: sit-vc                           TN: 1
  Annc Type: integrated                    Queue? y
Group/Board: G2
  Protected? n                              Rate: 64

The vectoring was exceedingly simple:

display vector 309                                              Page   1 of   6
                                  CALL VECTOR

    Number: 309              Name: ARS 8 to 9
Multimedia? n      Attendant Vectoring? n    Meet-me Conf? n           Lock? n
     Basic? y   EAS? y   G3V4 Enhanced? y   ANI/II-Digits? y   ASAI Routing? y
 Prompting? y   LAI? y  G3V4 Adv Route? y   CINFO? y   BSR? y   Holidays? y
 Variables? y   3.0 Enhanced? y
01 announcement 3442
02 disconnect   after announcement 61299
03 stop

The VDN took extension “8”, so that anyone attempting to use the old ARS access code would immediately be connected to the above vector.

display vdn 8                                                   Page   1 of   3
                            VECTOR DIRECTORY NUMBER

                             Extension: 8
                                 Name*: Dial 9 Instead -
                           Destination: Vector Number        309
                   Attendant Vectoring? n
                  Meet-me Conferencing? n
                    Allow VDN Override? n
                                   COR: 0
                                   TN*: 1
                              Measured: none

        VDN of Origin Annc. Extension*:
                            1st Skill*:
                            2nd Skill*:
                            3rd Skill*:

* Follows VDN Override Rules

Watching CDR for hits on extension 8 was hilarious for a few days immediately following this change. There were many hundreds of calls attempted using digit 8, despite repeated notifications that the dialplan was going to change.