The sting of rejection: Part 1

Ever have one of *those* days where you just aren’t on your game?  Usually we try to keep those days to ourselves and hope no one is noticing, but I’ll share a couple of pieces of one of my brain dead days in hopes that someone gets a good chuckle, that someone learns something, and that *I* never, ever, make this particular mistake again.

So there were two tasks remaining to complete my voice gateway setup: configure local conferencing and configure a single MGCP port on the router – in this case on a 2800 series.  Let me just preface this by saying this same setup had been done for approximately 20 other sites.  Imagine my surprise when neither the conference bridge nor the MGCP port registered. This blog entry will focus on the conferencing issue and mayhem that ensues when you just can’t see what it is you’ve done wrong.

There are a number of steps to creating a conference bridge on an IOS voice gateway.  The router configuration is going to look something like this:

dsp services dspfarm
sccp local GigabitEthernet0/0.1
sccp ccm identifier 1 priority 1 version 6.0
sccp ccm identifier 2 priority 2 version 6.0
sccp ccm group 1
bind interface GigabitEthernet0/0.1
associate ccm 1 priority 1
associate ccm 2 priority 2
associate profile 1 register my-Conf
dspfarm profile 1 conference
codec g711ulaw
codec g711alaw
codec g729ar8
codec g729abr8
codec g729r8
codec g729br8
maximum sessions 3
associate application SCCP

Once you’ve done this, you just need to add the conference bridge in Call Manager and it’ll register.  In theory. And in practice – if you do it right.  But I hadn’t.  My bridge was a bridge to nowhere – status Rejected. <cue sad violin music>

If you find yourself in a similar situation, there are several things you should check right out of the gate. Or should that be gateway?  But I digress.

Is sccp running on the router?

Enter no sccp, then sccp to confirm.

Is the dspfarm profile active?

Enter dspfarm profile 1 conference, then do a no shut.

Is the name of the conference resource correct on the router and in CUCM? In our example above it’s my-Conf, that *exact* name should be entered in CUCM. No wiggle room in this one – copy and paste it from the router to be sure.

And here’s the kicker.  At least what kicked me a few times over:

Is the conference bridge type you selected correct?

When I added the bridge to CUCM, I selected Cisco IOS Conference Bridge.  Sounds like a good choice, right? Uh, no.

What you really want is Cisco IOS Enhanced Conference Bridge. Which is what had been picked the other 20 times this had been done.  But for whatever reason, I picked the former, and let me tell you, the system does not provide a handy error message that says “hey bozo, you picked the wrong bridge type.”  Although, I am sure that will make it into the latest release.

Here’s what you will likely see as options in the drop down, go ahead and make the enhanced selection, you deserve it:

If, however, you choose poorly error either due to oversight or just not knowing any better, you will a status of Rejected for the bridge. In the RTMT Application Log for the CUCM server, you will likely see this error message over and over again:

: 37326: Feb 08 06:02:00.522 UTC : %CCM_CALLMANAGER-CALLMANAGER-3-DeviceTransientConnection: Transient connection attempt. Connecting Port:0 Device name [Optional].:my-CONF Device IP address.: Protocol.:SCCP Device type. [Optional]:52 Reason Code [Optional].:3 Cluster ID:StandAloneCluster Node ID:MYCMPUB

And if you are industrious enough you can track that reason code down, but it doesn’t necessarily shine much light on the situation:

So just add “Confirm the correct conference bridge type, you ninny” to your checklist when configuring a conference bridge on an IOS router.

And try very hard not to overlook this mistake the 90 times you check your configuration afterward.  It’ll save you a few hours of head scratching and an embarrassing call to TAC.

*In order for your devices to use the fabulous conference bridge you’ve just setup, be sure to assign it to the appropriate Media Resource Group and Media Resource List. Also, be certain you have assigned the MRGL to the devices or device pools that will need it.

Publish date: 02/09/2012

11 thoughts on “The sting of rejection: Part 1

  1. The resource name in CUCM can only be 15 characters long, keep that in mind when naming your resource in IOS.

  2. Nice 🙂

    And what was the story with the MGCP port registration being rejected? Wrong slot/card type?


  3. Not to sound like a rookie but why did you want this feature? What does it offer to the end user?

    1. by having the conferencing local to the site, the voice traffic doesn’t have to travel across the WAN to be processed by conferencing resources, so less latency. Very good for sites connected by lower bandwidth links.

  4. If you’ve ever used TAPS (or just BAT for that matter), then the DatabaseConfigurationError makes sense. When you BAT in a phone with the wrong model type, you get the same error.

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