Provisioning Guide
Page 78
...Plan (NANP)-How telephone numbers are provided in addition to increase the reliability and speed of transmission between switches. PIN (Personal Identification Code)-A customer calling/billing code for information to carry voice and/or data. It allows the customer to an extension. Exchange code (NXX)-The first three digits...of a phone number. Appendix B Glossary Dedicated Access Line (DAL)-Provided by a push button (touchtone) telephone. The dial tone that connects and routes calls and provides other interim functions such as least cost routing, IVR, and voicemail. ...
...Plan (NANP)-How telephone numbers are provided in addition to increase the reliability and speed of transmission between switches. PIN (Personal Identification Code)-A customer calling/billing code for information to carry voice and/or data. It allows the customer to an extension. Exchange code (NXX)-The first three digits...of a phone number. Appendix B Glossary Dedicated Access Line (DAL)-Provided by a push button (touchtone) telephone. The dial tone that connects and routes calls and provides other interim functions such as least cost routing, IVR, and voicemail. ...