CUCM External Access Code

[Levi Halford]

Hello Everyone,

We have a large CUCM cluster.  The hardware is getting old. We are migrating off of 5 digit extensions and onto new hardware hosting a completely new cluster.  Planning for future expansion we wanted to move to 7 digit extensions.  However, we have an external access code of 8 and most of our DID's in use start with an 8.  We want to change the user's dialing habits as little as possible.  We also want the dial plan to be as clean as possible. We don't really want to move to 10 digit extensions, or tell users to dial 10 digits for local PSTN calls.  We wanted the users DID and internal 7 digit extension to match everywhere possible.  We needed to find a way to avoid losing the secondary dial tone.  We also want to make sure the T302 timer isn't invoked when a user dials an internal extension or 7 digit local call using the access code of 8.  We will run into the same issue using an access code of 9.  We have DID's that begin with 9 as well.  Long story short, Has anyone ever entertained the possibility of or seen any issues with using # as an external access code to avoid all of this.  

[jonathan.salter]

Can you give me an example of what you are intending to dial.
What extention number and what DID do you expect that will be overlapping?

[Levi Halford]

We have DID' like 862XXXX.  Therefore, we'd like the user's "A's" extension to also be 862XXXX.  When user "B" picks up the phone to call user "A" by dialing 862XXXX the CUCM will have two possible matches left. The 7 digit internal extension and a local PSTN pattern 8.[2-9]XXXXXX.  Since the user has only dialed 7 digits and the PSTN pattern is 8 digits the T302 timer will be invoked.  Also, in this scenario the secondary dial tone has been skewed.  If we set the internal extensions as mentioned above and set the PSTN patterns with a #,                    (ie) #.[2-9]XXXXXX removing the # predot, this would resolve both issues. 

[Jaime Valencia]

#

The octothorpe (#) character generally identifies the end of the dialing sequence. Ensure the # character is the last character in the pattern.

The route pattern 901181910555# routes or blocks an international number that is dialed from within the NANP. The # character after the last 5 identifies this digit as the last digit in the sequence.

https://www.cisco.com/c/en/us/td/docs/voice_ip_comm/cucm/admin/8_6_1/ccmsys/accm-861-cm/a03rp.html

[Levi Halford]

Jaime,

    Thanks for your response.  I know that the # symbol is typically used as a terminating digit for CUCM, CUCCX and also by Unity Connection.  This is very common.  However I haven't found any configuration issues or conflicts using it as an external access code on my PSTN patterns.  So, I was hoping someone else had tried this already and could share their experiences with me prior to me rolling it out.