The dial plan or telephony numbering plan describes how voice calls are routed within the network and explains the site numbering plan and site-to-site dialing instructions. To replace or integrate the legacy PBX systems with the IP telephony systems, you should ask the customer the questions listed in Notes/Comments" section.
3
Has the organization developed a new dial plan for the IPT deployment?
4
Has the organization determined gateway-specific requirements, including protocol-supported and supplementary services (such as call hold, park, and conferencing)?
5
Has the organization determined gateway site-specific requirements such as encoding, calling line ID (CLID), DID support, analog or digital support, and fax relay?
6
Has the organization decided to implement TEHO? If yes, obtain the toll-bypass information in Table C-7.
Site Name | On-Net Site Access Code | No. of Digits in Station Numbering Plan | DID Ranges | Station DN Numbering Ranges | Station Intercom Numbering Range | Voice-Mail Numbering Range | Current Number of Users | Expected Growth of Users in Next 3 Years |
|---|---|---|---|---|---|---|---|---|
COR Group | Phone Types | Type of Access Granted |
|---|---|---|
COR 1 | Assigned to lobby phones | Local calls, emergency calls, toll-free calls, service calls such as directory assistance, and calls to other sites |
COR 2 | Employee phones | All access given to lobby phones plus long-distance calling |
COR 3 | Executive phones | All access given to lobby and employee phones plus international dialing |
Site Name, PSTN Access Code | DID Extension Range | Local Calling | In-State Toll Calling | In-State Toll Calling | |
|---|---|---|---|---|---|
Area Codes/Exchange | Number of Digits Dialing | Area Codes/Exchange | Number of Digits Dialing | ||
Use Table C-5 to document the current numbering plan in the organization, the current number of users, and the estimated growth in the number of users at each site. You need to use the estimated growth in the number of users when sizing the call-processing servers and voice gateways to accommodate the future growth.
Use Table C-6 to describe currently implemented Class of Restrictions (COR) groups in the PBX. Table C-6 shows some sample information that helps you to understand the type of information that you need to collect. Use the information collected in Table C-6 to define the calling search space and partitions in the CallManager.
If toll-bypass or TEHO implementation is required, you need to obtain the information listed in Table C-7 on a per-site basis.