An outbound number will not be dialed unless it matches the Dial Plan of the Phone, ATA, or PBX. This article has useful links and resources for understanding Dial Plans by Manufacturer.

Dial Plans are sequences of characters used to translate dialed numbers into outbound dial strings. Dial Plans can be used as filters; to allow, disallow or manipulate dialed numbers. If a dialed number, in the device, matches a set Dial Plan the device will then transmit the dialed numbers outbound.

Dial Plans can be used to prevent calls to certain destinations such as 411 and International Numbers or to add in an area code for 7-digit dialing. Dial Plans look very similar from manufacturer to manufacturer but are not always the same. Most dial plans are based on the (MGCP RFC 3435) Dial Plan but have modifications for various reasons.

Yealink Dial Plans

Standard Yealink Dial Plan

1xxxxxxxxxx

[2-9]xxxxxxxxx

[469]11

You can find more detailed dial plan information in the Yealink Administrative configuraiton guide.


Cisco Dial Plans

Standard Cisco Dial Plan

(*xx.|[3469]11|0|00|[2-9]xxxxxx|[2-9]xx[2-9]xxxxxx|1xxx[2-9]xxxxxxS0|<:1>[2-9]xx[2-9]xxxxxxS0|xxxxxxxxxxxx.)
Cisco DIal Plan Documenation
http://www.cisco.com/c/en/us/support/docs/collaboration-endpoints/spa901-1-line-ip-phone/108747-pqa-108747.html


Polycom Dial Plans

Standard Polycom Dial Plan

xxT|0T|011xxx.T|1[2-9]xxxxxxxxx|[2-9]xxxxxxxxx|[0-9]xxxT|*xx1[2-9]xx[2-9]xxxxxx|099xxxxxxx.T

Polycom Dial Plan Documentation
http://support.polycom.com/global/documents/support/technical/products/voice/Understanding_Digit_Maps_Tech_Tip.pdf

Vtech Dial Plans

There are three dial plans per account on Vtech Phones.The following are the default dial plans

sip_account.1.dial_plan="x+P"
sip_account.1.call_restrict_dial_plan=
sip_account.1.emergency_dial_plan="911|933"
Vtech Dial Plan Documentation: Page 52
https://cdn-media.vtechphones.com/media/p/document2/products/%7BC1D87BF6-0788-4541-A61B-F45AC6D29EB9%7D/VTech_VSP736_Admin_Provisioning_Manual-Rev-2.pdf

Grandstream Dial Plans

Standard Grandstream Dial Plan

{ [349]11 | [2-9]xx[2-9]xxxxxx | 1[2-9]xx[2-9]xxxxxx }

Grandstream Dial Plan Documentation
http://www.grandstream.com/support/faq/product-related-questions/gxv3140-ip-multimedia-phone/making/receiving-calls