Troubleshooting and Adding Missing SBC Routes

As more and more phone numbers are allocated within the North American Numbering Plan, or NANP, more routes must be added to Ringfree’s Session Border Controllers to accommodate the new numbering prefixes. An example of a prefix would be 1828555 and once added as a route in the SBC would serve as the means of routing calls to destinations that begin with that prefix. Formerly, calls to missing routes would be caught by a catch-all route and associated with the US48+Ext calling plan, however as of November 2016 calls to US48+Ext numbers require routes as well.

Identifying a Missing Route

From time to time you will have a customer who can not dial a particular number. To check and see if this is a missing SBC route, the simplest method is to dial the number from an extension on the Ringfree phone system. Given that the Ringfree phone system has extended NANP and international dialing enabled, successfully dialing the number is a solid indicator that the issue may very well be a missing SBC route for that number’s prefix.

To confirm the missing SBC route log into the SBC, click on the “Routes” tab across the top, and using the provided search/filtering tools, enter the following:

  • Route Table: All
  • Search For: The first 7 digits of the number (1NPANXX format)
  • In Column: DigitMatch

If there are no results, then the route is indeed missing. As a sanity check, you can always check a known route to make sure your search data has been properly input.

Adding a Missing Route

First identify whether the route is for the US48 or the US48+Ext calling plan. To do this, search for another route with the same area code and note the value of the Tbl column on the far left. A value of 65533 indicates US48 and a value of 65534 indicates US48+Ext.

Once you’ve identified the calling plan, Click the Add button located toward the top of the Routes page and enter the following (default values indicated):

  • Alias: The route in 1NPANXX format (i.e. “1828692”)
  • Digit Match: Select “Digits” and enter the route in 1NAPNXX format as above
  • Extension: 1 (default value)
  • Route Table: Select either US48:65533 or US48+Ext:65534
  • Time of day routing: weekly (default value)
  • Start time of day: Monday 00:00:01 (default value)
  • Stop time of day: Sunday 24:00:00 (default value)
  • Minimum length match: 6
  • Maximum length match: 40 (default value)
  • Route Group: None (default value)
  • Policy: top_down (default value)

At this point you’ll need to add the trunks. For US48 routes, set the following:

  1. Level3:99996
  2. Thinq:99998
  3. VoipInnovations:99997

Leave the Load Percentage blank and leave Continuous Routing set to yes.

For US48+Ext routes, simply set the first (and optionally more) trunks to Thinq:99998. Once completed, click the Submit button and the new route will be live.