CUCM 8.x – Block Inbound Calls by ANI (Calling Number)

If you are using to SIP or H.323 gateways, it is quite simple to block inbound or outbound calls at the gateway based on ANI (Calling Number) or DNIS (Called Number); the dial peer configuration can match based on either. However, many CUCM deployments run MGCP gateways because they are easier to manage when the voice guys are not network guys. Prior to CUCM 8.x, you could only block calls based on the DNIS if you used MGCP gateways. There is a feature in CUCM 8.x and higher that allows you to block calls based on ANI *or* DNIS, even if you are using MGCP gateways: Route Next Hop by Calling Party.

“Route Next Hop by Calling Party” is an option that can be applied to Translation Patterns in CUCM 8.x and higher. In order to block calls based on ANI, you will need to add 2 partitions and 2 calling search spaces:

• Partitions – InboundCalls_PT, FilterList_PT
• Gateway_CSS – contains InboundCalls_PT
• FilterList_CSS – contains FilterList_PT

You will also need to add several translation patterns:

• “!” – InboundCalls_PT – Route Next Hop by Calling Party – CSS: FilterList_CSS – use ANI to match the next step using the FilterList_CSS
• “!” – FilterList_PT – CSS: Internal_CSS – this matches all calls without a more specific match
• “” (blank) – FilterList_PT – CSS: Internal_CSS – this matches all calls without an ANI, i.e. if caller ID is blocked or unavailable

The Gateway_CSS is assigned to your inbound connection (SIP trunk, PRI, FXO, etc.) and the FilterList_CSS is used by translation patterns to route calls through the list of blocked patterns. At this point your call flow will look something like this:

Gateway_CSS
  InboundCalls_PT
    Translation Pattern
      “!” – route all calls
      Route next hop by calling party
      CSS: FilterList_CSS

FilterList_CSS
  FilterList_PT
    Translation Pattern
      “!” – route all calls not specifically blocked
      CSS: Internal_CSS
    Translation Pattern
      "" (blank) - route all calls without Caller ID
      CSS: Internal_CSS

In order to block numbers, simply add translation patterns to the FilterList_PT that match the ANI (Calling Number) and choose “Block this pattern”.

Live feed music on hold – hardware and configuration

Nearly every PBX in existence has some way to take outside audio and use it for music on hold.  In the past, Cisco sold a nifty little USB device (MOD-USB-AUDIO=) that would allow you to connect any audio source to a Call Manager server.  This worked great up until Call Manager 9; with Call Manager 10, all UC servers only support installation on virtual hardware.  In theory you could configure USB pass-through and add a USB device to your VM, but the audio quality is pretty poor and is not supported by Cisco.  Now what?

Call Manager Express – Class of Restriction (COR) Lists

I spend most of my time as a voice engineer dealing with Call Manager and Contact Center Express, but once in a while I get thrown a “small” problem involving Call Manager Express.  CME is generally deployed for smaller customers (<100 phones) who don’t need all the fancy features or capacity offered by full-blown Call Manager.  Unfortunately, most of my customers are fairly large so I don’t get to play with CME often.

A few weeks ago I had some spare cycles so I was tossed into a case for a customer having issues with their CME and some FXO lines.  Summary: they have 8 FXO lines, 6 of which in a hunt group, and 2 need to be assigned for 2 specific individuals at the company.  The hunt group configuration was tricky, but let’s focus on the 2 extra lines.  They want these FXO ports setup so that User1 and User2 always use 0/2/1 and o/2/2 (respectively) for outbound calls, so that when people call back they get the right person.  This would be a piece of cake in UCM: create a special partition and CSS for each of those users, add route patterns pointing to the correct FXO as the gateway, and apply the CSS to the user phones.  15 minutes of work, tops.  Except CME doesn’t have Partitions and Calling Search Spaces.

EIGRP Stub

OK, uber nerd post. There are two common practices I’ve seen quite often in the Cisco network world: 1) everyone thinks you need an IP services image for routing and 2) no one wants to pay for IP services images, so they just bootleg it. There is actually a 3rd one (“a routing switch is as good as a router”) but that’s a gripe for another day ..