Cisco Unified Communications Manager Express Overview


Now the Cisco Unified Communications Manager Express is for small to medium-sized environment. It could also be used as a backup strategy for a full-blown Communications Manager Solution where you don’t have a phone system at a branch or remote location. So in the event of a failure this Communications Manager Express could maybe kick-in if the WAN went down or we lost connectivity with those Communications Managers, so that remote site still had a telephony solution.

Now of course, the Communications Manager Express can do your Voice over IP for all of your phones. It could also support video, we have up to 350 IP phones that’s why I kind of call it small to midsize environments. We can still do conference capabilities, so we can set up those conference calls where needed. There is also the ability to set up Interactive Voice Response Solutions with the Tool Command Language or the TCL scripts that are involved and we can even setup a small automatic call distribution environment. So really there is no limit to a lot of the capabilities that you can have in a smaller environment. We also have the ability to integrate voicemail solutions into this, so we still have voicemail. It’s all a router-based architecture, so it’s kind of a nice neat little package if you will that everything is tied into for that again small to medium-sized solution if that’s what you’re looking for.

CUCM Express Supported Platforms

Now the various platforms that support this Communications Manager Express include the 2900 Series, Integrated Services Routers and the 3900 Series.

Platform Max. Phones SM Slots Max. T1/E1 Ports
Cisco 2901 ISR G2 35 N/A 8
Cisco 2911 ISR G2 50 1 12
Cisco 2921 ISR G2 100 1 12
Cisco 2951 ISR G2 150 2 16
Cisco 3925 ISR G2 250 2 16
Cisco 3945 ISR G2 350 4 24

However, if I was you and you were looking at purchasing a new platform I would definitely go to Cisco’s website. I go to for the Feature Navigator and what you can do is a couple of things – you can look at your existing platforms, what their capabilities are, what operating system you would need to support the Communications Manager Express and a lot of times when you’re looking at that you may need to look at how much memory you have in the device, because I find that as I take an older piece of equipment and I move forward with the IOS, I may need to add some more of RAM to it. So, it may be that you have an existing platform that you can do this on or you can look at these different devices and depending upon the number of phones and T1 or E1 connections that you need, it gives you an idea of which platform it is you need to support this.

CUCM Express Data Streams

Here is one of the key pieces of information that you need to understand so that you can know what traffic is actually going to be streaming across your network. There are really two protocols that are key in our environment right now and one of them is the Skinny Client Control Protocol or SCCP sometimes we call it Skinny for short or the Session Initiation Protocol (SIP).

CME Data Streams

You have a choice, these are the protocols that the phones and the Communications Manager use to identify “Hey I want to make a call”. The handset goes off-hook you dial some digits the Communications Manager Solutions are saying “oh okay let me look at these digits where do they need to be routed to”, so this communication back and forth between your phones and the device is done typically through either Skinny or SIP. Then let’s say okay here’s the four digits I dialed now I want to talk, I have a conversation, the phone is answered at the other end. What is taking place between these two – it’s a RTP Stream, that’s the Real-time Transport Protocol. Тhat RTP Stream does not travel through the Communications Manager Solution, whether it’s Communications Manager Express or the full-blown Communications Manager, that RTP Stream goes directly between the phones. In other words, the phone system really kind of drops out of it at that point and you guys have your conversation. Now let’s say we want to hang up, okay I hang up the phone. Now either Skinny or SIP whichever I’ve chosen is going to indicate from the phone to Communications Manager Solution this phone device hung up. So in other words the resource is now free again, so if another phone call comes down the pike we can go ahead and route that to the destination.

Key Features

The Communications Manager Express is really the older phone system replacement. If you were thinking about an older key system or PBX that stands for Private Branch Exchange where we have the separate phone system solution, this Communications Manager Express is the replacement for that device, because it is responsible for doing all the call processing and that’s what it used to be in the old days. So the call processing, the signaling, all of the features for the devices, all of the directory  services and all the different environments that we used to deal with on the key system or PBX are now really supported on the Communications Manager Express or even the Communications Manager Solution, whichever one you’re looking at. So, all of the key features that you would think about that you had with an older phone system you’ll definitely find in the new environment and then some, because of course the reason we’re doing this is because we have the capabilities now of really tying into that data network. I used to work with an environment where we had the separate devices, we had a separate phone system (in example some “digital” PBXes from Panasonic) we had a separate data network and we had something called Computer Telephony Integration and so that CTI support is what allows you to tie into the existing applications or even the applications on your phone system tie them into different information coming from your data network. So, CTI support has just grown immensely in this environment and it’s still here today, and its growing so much because really the sky is the limit. Whatever applications you can think of really can be developed for your Voice over IP solution. That is a huge key feature and you still have that with the Communications Manager Express even though, I call it the scale down or smaller solution does support that. You even have the ability to support remote people, so anybody who’s working in a small office or home office environment or if they’re telecommuting, if they’re out there in a hotel even those VPN solutions can still be supported in our Communications Manager Express Solution.

Cisco Unity Express

What’s the phone system these days without voicemail? I don’t think you could call into anybody’s phone system without having some sort of Auto Attendant or some voicemail solution that’s out there working. So, we do have the Cisco Unity Express, which is again curtailed to the Communications Manager Express Solution which allows us to have voicemail, so that allows you to have mailboxes to take messages for everybody. The Auto Attendant which is the “Hi, welcome to our company if you know your party’s extension…” so we have the Auto Attendant environment, we even have Interactive Voice Response. Now IVR is something that you need to make sure is supported and you need to make sure you have enough memory and the proper IOS, but it is supported so you could have an Interactive Voice Response solution as well.

You also have the ability to support faxing and we have Survivable Remote Site Voicemail, what’s that all about?  Remember I mentioned that the Communications Manager Express could fill a need if you had a full-blown Communications Manager Solution, which will see the topologies later on, but at those remote sites they actually don’t have a phone system sitting there, nor do they have a voicemail sitting there. So let’s say the WAN goes down, the Communications Managers are not reachable anymore. We could have the Communications Manager Express and this Unity Express Solution sitting there waiting in the event that were to occur, now we can still have voicemail while that outage is taking place, we still have all of our phone capabilities, while that outage is taking place. So these solutions can really fit quite a couple of niches for us when it comes to making sure that we have voicemail and we have all our features for our phone systems at all of our branch locations.

Unity Express Modules

With the Cisco Unity Express it’s just like the Communications Manager Express, we have to make sure we have the proper platforms, and you can see the 2800 / 3800 series and 2900 / 3900 series environments. But what I want to tell you again is look at Cisco’s website if you’re buying this brand new double check the latest hardware and the latest platforms. Basically, you’re looking at a module or a dotter board that’s going to fit into your devices and really it’s going to be based on how many mailboxes you need.

Platform Hardware Bundled
Max. IVR
Cisco 2800/3800 Series AIM2-CUE-K9 6 6 6 65 14
NME-CUE 8 24 24 275 300
Cisco 2900/3900 Series ISM-SRE-300-K9 2 10 10 100 60
SM-SRE-700-K9 4 32 32 300 600

If you look at this chart, you’ll see that we have various numbers of mailboxes that are supported and then based on that we have ports. Ports are basically virtual entry points into the voicemail system. For example if I had an AIM2-CUE-K9, that’s my board, I could have six phone calls going into my voicemail system, if a seventh one came along they might get a busy signal or get disconnected, but we have six ports in that environment, which on average could support about 65 mailboxes and you get about 14 hours worth of storage, so just based on that example that’s what you’re looking for. You’re looking for how many mailboxes and how many ports.

Unity Express Data Streams

Just like we looked at the Communications Manager Express’s, data streams and the voice stream, we’re looking at that with Unity Express and it’s really no different other than we just use SIP, that Session Initiation Protocol is what we use to communicate between the Communications Manager Express and the voicemail system. When we’re listening to our messages or talking and leaving a message that is again, going to be that RTP stream. These are the two basic protocols that we use to support our voicemail solution.

There’s also another entity to all of this and that is the Codec that stands for coder-decoder. Basically, what has to happen is your analog voice has to be converted into digital that’s what a Codec does and along with that you could also compress that voice down, so that you use less bandwidth. There are two Codecs, the G.711 codec, which is basically just converting your analog voice to digital format, then there’s the G.729 that does the conversion as well as does some compression. So, with the Unity Express we want you to know that it only supports the G.711 audio stream. But let’s say that you did have G.729 as a Codec that you chose you could go through a Transcoder, that’s a resource that allows you to convert between the different Codecs, so if you have that Transcoder, the Transcoder is necessary to go between the G.729 to the G.711 environment and back and forth.

Depending upon your solution and how well all of this pans out for you, you may not want to go with G.729 just because of the expense of the Digital Signal Processor Resources (DSP) that are necessary to do the Transcoding between these Codecs, so by default just so you know G.711 is supported with no Transcoding resources necessary, so that’s probably the best solution if you’re looking at cost.

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