The Cisco Unified Communications feature called Mobile Connect (also familiarly referred to as Single Number Reach) is truly a great feature of Unified Communications Manager, and can provide us with many efficiencies both in being able to be reachable just about anywhere, and in being able to be easily identified when placing inbound calls from our mobile phones into the CUCM cluster to our colleagues. As admins, we know that if we wish to have our users place calls from their mobile phones inbound to their colleagues inside the CUCM cluster, that we need to match up all or at least part of their inbound calling party number (CLID) to their CUCM Remote Destination. But what happens when what the carrier is sending CLID digits inbound to our IOS voice gateways that differs significantly from our Remote Destinations in CUCM, especially if we have truly embraced Cisco's push toward true Globalization in v7.0, v8.0 & v8.5?

The fact is that many, if not most European carriers (as well as many more all over the world) send CLID in through an ISDN PRI into the enterprise gateway with a preceding "0" as a courtesy  digit for easy recognition and ease in dialing back out, since this "0" is very commonly used as a carrier-recognized national dialing prefix. If we were speaking of the US and Canada, this "0" we are speaking of would be akin to dialing a "1" prior to the national number. Now in the US and Canada, if a carrier in the US sent CLID into a gateway with a "1" preceding any 10 digit number, this would work fine since the US/Canada country code also happens to be "1". However, the "0" preceding a variable length number is not valid in a true E.164 number format (e.g. If you dialed the phone number from outside of whatever country we were talking about, you would omit that preceding 0 from your dialed digits).

So what are we to do to get our inbound CLID to match our RD's?

That is exactly what we will explore here today in video format, as you watch a very small excerpt from our video-based solutions to one of the many new labs we will have in our new CCIE Voice Volume I & II workbooks.

Click here for the 25 minute video discussion on "The Trouble with European MGCP Gateways and Mobile Connect Inbound Calling Party Matching".

(BTW, if the video starts off with a bit of an echo, just hit CTRL-R to refresh the stream. And then stay tuned to this blog for some very exciting announcements about new formats for video solutions in the very near future)

Happy Labbing,


Mark Snow, CCIE #14073
About Mark Snow, CCIE #14073

You might say that Mark Snow began his networking career at the age of five, when his father, a patented research scientist at AT&T Bell Laboratories, started sharing his knowledge with Mark. He has been working with data and voice technology ever since, beginning with Unix System V and basic analog telephony and progressing to large data networking projects and large phone systems in both enterprise and 911 PSAP environments around the world. You’ll see Mark in all of INE’s Voice video courses and live Bootcamps. Mark Snow is also an accomplished pilot, and when he isn’t learning, labing, consulting, or teaching, he can be found jumping out of a perfectly good airplane, hanging off a rock somewhere, skiing out west, or just enjoying a quiet day at the beach with his wife and two wonderful kids. You may contact Mark Snow at msnow@ine.com, follow him on Twitter, or find him helping others in INE’s IEOC Community Forum.

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