Posts Tagged ‘Dial Plan’
So let’s recap, we’ve discussed the how and why of Globalizing every Calling Party Number – and we recall that this occurs as the first step inside CUCM as the call arrives Inbound at any of our enterprise gateways. We’ve also taken a good look at Localizing each number – and we recall that this occurs as the last step inside the CUCM as the call leaves Outbound to each destination IP Phone. So it logically behooves us to next take a look at the task Cisco labels “Mapping Global Calling Party Numbers to their Local Variant”. Now this may sound a bit daunting or even just plain confusing, but rest assured that it isn’t, and it could probably even stand a naming refinement – in fact for the rest of this article I will simply refer to it as “Call History Dialing” since that is more properly what we are wishing to perform.
In the last installment of this series, we took a brief look at the history of the ITU-T’s E.164 recommendation, as well as, hopefully, an understanding as to why we might want to begin building dial plans in CUCM versions 7 and later in a truly Globalized format, and we took a look at the basic configuration to do so. In this post we will look at the next phase in the process, namely Localization.
While having been covered before, there seems to still be quite a lot of confusion surrounding Cisco’s newest call routing additions and features in CUCM 7. These are best cleared up since they not only are completely fair game as testable topics for the CCIE Voice lab, but also since CUCM 8 is just about to FCS and includes a great deal of call routing enhancements of its own (such as policy-based call-routing and inter-cluster dynamic DN route building) which will only build on the complexity of CUCM 7’s call routing enhancements (I’ll blog on some of the new features of CUCM 8 another day if anyone is interested).
In this blog article I will first list the new call routing features, then explain why we might be interested in using them (which requires a bit of understanding of history that we will go over), next move on to how to configure them, and finally wrap up with some real world examples. This all might take a while to explain with accuracy and clarity, and therefore will be broken down into sections to assist the reader with an easier course of digestion and absorption. Also it should be noted that before we begin, we are only going to seek to understand the E.164 numbering recommendation in this blog article, that is – we will not go into the specifics of E.164 NUmber Mapping (a.k.a. ENUM) here – although I will cover that in a later blog article.