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telephony:nbx:configuration:considerations_for_vtl_calls

CONSIDERATIONS FOR VTL CALLS

Fact:

  • NBX 100
  • V5000 NBX
  • Dial Plan
  • V3000 NBX

Fix:

Dial Plan Considerations for VTL Calls:

PreNote: The NBX Dial Plan Editor GUI software (3C10475) will automatically create all your VTL site entries, and setup the customized LCD formatting pretranslators for you. Don't be without this valuable tool for creation and maintenance of your multi-site dial plans!

For VTL calls, the receiving site NCP removes BOTH the IP address and password on the receiving system automatically before processing the digits in the dial plan. There is no need for a pretranslator to strip the IP address and/or password for dial plan digit processing.

For example, if system A dial plan is configured to send for VTL Hopoff 10*20*30*153*password*918005551234 …this is sent to the B system NCP, which removes the IP address and password, and just 918005551234 gets dumped into table 1 on the receiving system for processing of digits. Technically, it follows dialing as to what table the VTL ports are in Site B. VTL ports should all be in Table 1 as devices using on all systems.

This is inconsitent from other dial plan devices/ports , because the IP address and password is stripped off for the CALLED party digits (dialed number for dial plan processing) by the receiving system NCP, but the NCP will use the IP address for the Caller ID header; the IP address is NOT STRIPPED by the receiving system for Caller ID tag. What makes it also inconsistent from other devices is, when you use a pretranslator for a VTL port, and click on “Devices Using” - for ANY other device this will pretranslate CALLED party digits (dialed digits for dial plan processing). But for VTL, when you put VTL ports in a pretranslator, it is pretranslating only the CALLING party digits (caller id) for the LCD. For every other device, you must click on “Devices using for CLI” button in order to have the pretranslator process the CALLING party digits, but it is backwards for the VTL ports. So this means

you should never use “DEVICES USING FOR CLI” for VTL port pretranslators

Here's a summary of all VTL dial plan Caveats:

  1. For VTL call, the receiving NCP always strips off the IP address AND password if it is present, and the remaining digits are dumped into table 1 for processing just like any phone would dial the same digits at the receiving site
  2. If you need to do digit manipulation for the DIALED digits for dial plan routing at the recieving system, you need to do this at the SENDING SITE, not the receiving site, for VTL calls.
  3. Make a pretranslator and ONLY put VTL ports as Devices Using (not dev using for cli) and use this for pretranslating CALLER ID for the VTL calls, such as removing the IP address which normally shows on the display (NCP does NOT remove the IP address for the Caller ID header, only the Called party digits), and replace the IP address with the Site Name, for a customization of LCD tags for VTL calls extension to extension.(the following does NOT apply for POTS line hopoff)
  4. When doing Hopoff for VTL calls, And the receiving system has a PRI or T1 that sends Caller ID to Telco, you must do a further pretranslation of the Caller ID, to now remove the Site Name that you added for VTL extension to extension calls, and make the Caller ID now look like a 10 digit phone number, so that telco will not reject the call due to wrong caller ID tag, and so that the party being called will see a valid caller ID tag. To do this, you use the CLIP pretranslator (Outbound Caller ID Pretranslator) on the site with the PRI that hopoff is being done.

You must match whatever unique caller ID tag is being sent from each remote site doing hopoff, and replace it with either a static 10 digit BTN (Billing Telephone Number, ie, the “main” number for that remote site doing hopoff), or if DID ranges are being used, you could prepend just the area code + exchange after stripping the unique caller ID tag on the VTL call so that an exact DID would be presented to telco for all VTL hopoff calls.

This “unique caller ID” would be either the IP address (if you don't use the LCD formatting Pretranslator for VTL ports to change the IP address to a site name), OR, it would be whatever site name you have changed the IP address to in the VTL LCD formatting pretranslator for cosmetic reasons.

David Gonzalez 2021/04/13 10:27

telephony/nbx/configuration/considerations_for_vtl_calls.txt · Last modified: 2021/04/13 10:39 by dgonzalez

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