A new feature arrived with CUCM 7.x and higher and that is the new ability to use the new globalized e.164 feature. This feature is simply adding a + followed by the 1 to 3 digit country code, then the National Dialing code, and finally by the subscriber code.
The + actually means the country’s access code that I happen to be traveling in. So in Europe, most likely the international access code would be ’00’. However, on my cell phone I would dial +14089347568 then the cell phone carrier would strip the + and replace it with 00. Therefore as an end user, no matter what country I am dialing from, I never have to know that country’s international access code to call home.
Now, this same idea has caught on in PBX systems to provide globalized call routing. The overall goal with globalized call routing is that an end user or carrier would normally enter or transmit the digits to the PBX or CUCM using a local format like 10 digits in North America. The number would then be converted into a global format and routed accordingly.
If the call was going off net, the user would dial a 7 or 10 digit number, which would be converted into the global format. Then a route would be matched and before sending a call setup back to the carrier, the number would be converted back to the local format needed by that local carrier.
Seems a little busy, but if you have a worldwide business with remote offices in Europe, Asia, and South America, using the globalized call routing method will significantly reduce the complexity of your overall dial plan – especially when you are trying to incorporate Toll Bypass and/or Tail End Hopoff procedures.
Another reason that you may want to move to this global format for internal routing is the fact you may be integrating with Microsoft OCS 2007 installations. Microsoft OCS 2007 defaults to global routing using the global e.164 standard, and in order to accept this number type and route it effectively, it would make more sense to go ahead and adopt this standard within your CUCM installation as well.
Author: Joe Parlas