In the world of telecommunications, Time Division Multiplexing (TDM) is at a crucial turning point. Once a big deal, it’s now facing doubts because of all the new digital stuff. Let’s dive into the discussion about whether TDM still matters, considering how we stay connected today.

Some Enterprise level telecom executives debate the topic

Recently had a well known IP-Telephony vendor (who shall remain nameless) tell us that “TDM is dead”….hmmmmm….guess that doesn’t count my 8,000 plus TDM stations in place today…..

I would love to hear your thoughts on the evolution of IP telephony

voice over ip

 and your plans for deploying, increasing deployment, or stopping deployment…or anything else you would like to add.

I have 85,000 TDM lines that would disagree with that well known vendor.  That said over the next 5 years, I’d bet that we migrate some to IP for those that actually NEED the functionality.  Or better yet, if IP telephony becomes more cost effective than what we already have.

We are right in the middle of selecting the VoIP platform for migration of our 15,000 handsets, so this is right in front of me. I think the message he was trying to send was that in terms of further development, the platform is dead. Obviously, we can get support for the old gear for some time in the future, but the industry is not putting money into developing the old systems.

It’s true that the switch manufacturers are not investing at all in TDM, but AT&T has just come out with a bolt on UC product for Centrex. Not sure if they developed it completely internally or with 3rd parties.

TDM is far from dead. But for the purpose of this discussion, we need to differentiate between VOIP-based PBXs and VOIP lines.

It’s just a matter of time before digital PBX systems are almost completely replaced by VOIP-based PBX systems (which are capable of using TDM lines), but probably not for at least several more years.

As for VOIP lines vs. TDM, unless/until the cost of bandwidth comes way down from where it is now, TDM lines are here to stay.

G.729’s call-quality still isn’t completely ready for prime time, and G.711 allows for only two-thirds as many simultaneous calls as a regular PRI (making VOIP lines cost-prohibitive vs. TDM).

I have been involved in migrating 1500+ users from traditional TDM to VOIP phones. It has been a 5 to 6 year process and has had some definite challenges along the way.

Our current environment is Nortel/Avaya voice with Cisco data switches in the closet. The biggest challenge early on was POE (Power Over Ethernet). Cisco and Nortel refused to play and so we went from using wall warts, to power hubs, and then they finally came together on POE.

And we were finally able to get power for the phones from the Cisco switches, which helped immensely. Keep in mind that one of the biggest expenses is not the VOIP phones, but the Data switches in the closet.

So if you can justify changing out all of your closet switches to support POE VOIP phones then your good to go; or you may already have them in place which obviously would make things easier.

The other challenge you will face is guaranteeing end to end QOS across your Network. This becomes a challenge based on what you have for Core/WAN routers.

This only matters if you have low speed Wan links. If you’re just a campus environment then QOS is not an issue.

The other challenge that comes with VOIP is the interfacing you will have to do with the Data guys.  They will obviously be involved with a lot of the setup. We had some pains trying to deal with the Data team they do not understand voice and so it becomes a tug of war at time.

But once you have addressed all of the initial challenges VOIP does have some benefits, MAC’s (Moves Adds & Changes) become a lot easier, you can utilize your Data network instead of having to have two disparate Networks Voice and Data.

One other thing that becomes a challenge is 911.  Without knowing your environment I am not sure what you may face, but keep that in mind as you continue to investigate VOIP.

Having been involved in the evolution of PBX telephony (Mechanical Crossbar; Wired logic electronic SG-1, CrossReed; CPU/TDM software based Rolm, Fujitsu, NT-1; and the IP iterations of Cisco, et al) it has been the costs to manufacturer and subsequent end user installation and maintenance that drove the process.

So it was a newer technology’s economics that determined an older one’s demise. Also with each iteration the ‘marketers’ proclaimed:

“The King is dead, long live the King.”

I never meet a CFO I couldn’t convince otherwise.

Need some advice on VOIP. Been in Telecom 30 yrs. Majority of time on Avaya (or whatever their name was at the time). Have a Definety G3.

We were bought out a couple of years ago by a company that is very financial strong and rapidly growing in the States & Europe. Started out as Workers Comp, now we are full service provider for companies. We do Payroll and any kind of insurance you need (not health).

So money is no problem and they want the best technology. They are a Cisco house. Data & Voice is run out of Cleveland. We are in Boca Raton Fla and moving our office, all 200 users in the Fall of 2011.

I’ve been told to get up to speed on VOIP and I don’t know where to start? I need basic understanding of VOIP. I will only be doing the programming of desk sets along with Auto Attendant & Voice Mail. Everything else is done by the IT in Cleveland.

So any suggestions of where I can or should start learning?

Avaya has a short booklet, “VoIP for Dummies” that should give the basics.  Ask your rep. If they still have it.

Folks have already covered the obvious, so I won’t dwell on that, but I will remind you that moving to VoIP will change the way your telecommunications department deliver services.

Now, I’m not talking about the obvious change in the underlying technology, I’m talking about the MAC process. For example, you may not have to have a technician go to a user’s desk to activate the phone.

The user may plug his own phone into the network, and they move it with our without authorization to do so. IP will allow new technologies such as WLAN devices that provide exceptional amount of user mobility, and don’t forget about softphones on laptops in both a wired and wireless environment. This is all wonderful stuff, Fletch, so why are you bringing it up?

Well, those of you that know me know exactly why am bringing up, but for those of you that don’t, here is the issue. Three little digits, 911. Now I’m not saying that voice over IP and 911 don’t mix, because they do.

What I’m saying is that when you move to voice over IP you empower your users with mobility, and that exact same empowerment can make 911 a challenge.

Fortunately, the technology has advanced on both the call server side as well as the 911 services side, and dealing with 911 is nowhere near as difficult as it used to be in the infancy of voice over IP.

I am not saying this to scare anyone, and I’m not saying “don’t deploy VoIP”. What I’m saying is don’t forget about 911. Make sure you understand how E911 works, and make sure you understand exactly how your system deals with it.

You may find that voice over IP gives you implementation challenges that you weren’t expecting, or budgeting for. And there are way too many people talking about E911 with INCORRECT facts than I am comfortable with.

telecommunication procurementHolding on to a “stagnant” technology is not in the best long term interest of your organization. (I am guessing you are either government or hospital/education). TDM is not dead per se but is definitely static as far as growth goes.

It has been about a decade now since the first evolution of VOIP in the enterprise and private markets.

In the last 10 years the manufacturers have all shifted their focus towards VOIP because of it’s obvious selling points and huge infrastructure and capital investment advantages for the enterprise markets. It’s here and it IS a reality.

There will always be niche markets where the need for older technologies will still exist. However these markets are shrinking RAPIDLY because of the huge advantages for VOIP.

I respectfully disagree with many of the comments about VOIP that I have seen here and am quite shocked to be honest with some of them. “Unless the costs
of bandwidth comes way down from where it is now”?

Bandwidth on WAN circuitry has PLUMETTED in the last decade as the technology advanced and is every bit as cheap and virtually unlimited compared to traditional PRI or copper phone lines.

The fact is that many of the carriers actually charge you more for the older technologies now because they have to try to support it on newer base platforms. It’s really a matter of negotiations with carriers and quality of your design and your own technology skill sets available (your people).

“G729 call quality is not ready for prime time” sounds just like “cell phones will never become standard” arguments from 20 years ago. It just isn’t true. QOS is almost “out of box” standards now and VERY easy to implement.

I was in the TDM based field as a technician for an interconnect company ( Nortel,NEC etc) and as onsite technical expertise on TDM systems for many years. I have now seen 4 different enterprise level companies grow from TDM to VOIP.

One company I was with converted their whole operation to VOIP (over 2k endpoints/phones) in over 130 offices across the US and 4 in Canada in less than a year. Total capital investment was about 2 million.

The first month alone we saw a 40k decrease in the costs of interoffice and LD calling rates due to older circuitry removal, contract renewals with carriers etc. Do the math and see the ROI.

(One of our offices was in NY City and we routed their LOCAL calls through the WAN to San Diego CA and then BACK to NY via our LD trunks in SD and it was cheaper than if we made the call on a traditional copper line right out of their office with the local carrier.  The manager was “stunned” and his budget was very happy.

It comes down to this for the “future” as you ask.

  1.  TDM is dead…..but understand that statement.
  2. TDM logistical support and expertise is drying up RAPIDLY. Mfg’s are “sun setting” many TDM products that were top of the line equipment just 5 years ago.
  3. Carriers are walking away from TDM literally by the day and that means only 1 thing for customers to continue to use it….COSTS will go up for you if you do not embrace VOIP and PLAN for it
  4. Your environment with 8k endpoints I am AMAZED you have not at least started to transfer your platform…but that really comes down to your environment and budget.
  5. Planning /engineering and BUDGET to convert. And, at the end of the day, YOUR people

Look around you, seen a telephone booth on the street lately?? Do you still have a copper phone line in your house? 47% of US households now DON’T…. 5 years ago, that was only 21%.

My take, within 5 to 10 years…and I am being generous….TDM will be all but be gone.

Exactly, as networks become more robust and bandwidth becomes less expensive, enterprise voice systems could potentially move out to the carrier or even, perhaps, co-ops.

And while SIP will certainly add flexibility to the handsets we choose, SIP service offerings will eventually enable us to all but ignore capacity concerns. As long as the pipe’s big enough, you can take and receive as many calls as you like. No more buying extra PRIs just to get enough channels to cover your peaks, just pay as you go.

Internet and Networking

Voice is an application that runs on a server (managed by the server/storage team) that runs over an IP network that is managed by the Network team. Traditional telecom is morphing into Unified Communications with contain the entire spectrum of end user communications: Voice; Voice Mail; Video; IM; Collaboration; etc).

Indeed , voice is a specialized application, like SAP, and requires architects, engineers, and administrators to design and manage it effectively.   It is not Telecom vs. IT or Telecom vs Networks…… old school thinking that may live on in some organizations but the trending says otherwise.  The discussions in 2011 should not be surrounding TDM vs. VOIP, but rather “on premise” vs. Cloud.

While Voice-in-the-Cloud (enterprise) is still in its infancy I would be thinking hard before making a long term investment in a new on premise, proprietary PBX system.  Because if not cloud, SIP is clearly just around the corner and those $200-300 proprietary handsets will be a thing of the past.  Just my opinions

I am not sure that I agree with you.  I see that telephony has evolved into an application that runs on the network.  Granted, it requires special treatment (like significant QOS monitoring), but really, it is just another application.

We are morphing support for telephony into two distinctive arenas, the analyst side which supports the applications of telephony (standard features and functionality, ACD, our Call Center app, Genesys, call recording, telemanagement system, and now all the collaboration tools will be under our support like video conferencing) and the technical side, which will merge in with the network engineers.

As a telecom professional, an old school TDM telecom manager, I am really excited about the change, I think we have the best technology in all of IS, and I can’t wait to bring it to our enterprise and see what happens with the new collaboration tools.

The future of the telecom manager or technicians/administrators is very simple……evolve into a network engineer/ manager or retire. It really is that simple. All of what you stated in your email was stated in different terms in mine…you being a much better writer than I am but the same message none the less.

And the message you ask about jobs or positions is again very simple to answer. Phones are simply ancillary devices on the network and you don’t need a “telecom dept” to maintain them. The future for the “old phone tech” is gone. You either adapt to networking technologies…i.e.

VOIP or eventually…you are eliminated. Look at what’s left in the Interconnect support vendor arena. What was once….as recent as 10 yrs ago……a huge employer, is now a shell of itself. I worked for one of the largest in the country. That company in the last 10 years has changed ownership about 5 times and is now about a 10th of its size in its heyday.

Evolve……with the exception of a few niche markets….govt and hospital/education……….the TDM world is dead!!!!
It’s like mainframes…..seen one around lately???

I have been trying to look into the crystal ball with regard to our industry. Some observations:

  • Traditional landline, especially in residential, is dwindling.
  • SIP trunking options are growing and potentially offer greater options and flexibility than PRIs.
  • With the use of DHCP and PoE, VoIP handsets/workstations are increasingly more flexible to manage than their TDM counterparts. (no punch tool required!)
  • The cost-per-port on network gear is dropping while switchgear companies are moving to more uniformity and standardization (e.g. Cisco vs. Force10)
  • Routing VoIP calls over the LAN, the WAN, and even the Internet is becoming easier and cheaper than ever before.
  • The cost of local, LD, and even international calling services is gradually becoming a loss leader for carriers to sell other services. (hello bundles and sub $.03 LD, even free LD on cellular)
  • Hosted voice solutions by carriers are slowly growing and becoming a part of the regular conversation with clients

I’m not stating anything revolutionary here. It’s all pretty obvious, I think. What I’ve been twiddling over is how these things and others are going to fundamentally change how voice is done. Cellular has become not only ubiquitous but threatens to all but KILL residential landline telephony.

There will always be a contingent of residential landline but it will eventually be pushed to the periphery and ultimately priced to prohibit. That being said, VoIP has the potential to do the same to TDM (both in the PBX space as well as the telephony space) at the enterprise level.

What I’ve been thinking about is how that could potentially take place and what path the changes may take. I suppose the thinking is a little selfishly motivated as I’m wondering what the job of a telecom manager will look like, say, ten years from now.

We made the shift to VoIP in 2007 and already I’ve seen a shift in some responsibilities as some work gets displaced. Moves, for instance, are completely handled by facilities/service desk or even the end users now. Network engineers have a lot more involvement in operational issues – particularly troubles and outages – now.

I’m seeing enterprise voice gradually becoming all but self-service and the role of the telecom pro to be a combo of “Maytag repair man” and implementation with very little daily operational involvement.

Voice appears to be becoming a commodity of sorts. So where’s the wave?

Anyone else pondering the future?

We are already seeing this today in cloud based providers offering a pooled subscription across multiple sites.  i.e. 100 lines shared among 10 facilities with overflow capabilities that allow the subscriber to go over capacity without incurring extra cost as long as it stays under a specific threshold.

Traditional telco only comes into the picture in two scenarios: Reliable data service is not available at the site or for backup redundancy purposes only.

Internet Connection

This is why I like hosted VoIP providers that deploy a “home” box at each site capable of supporting secondary internet connections, ancillary devices, paging and MOH interfaces and lastly, backup trunks that can be pushed to the Polycoms, Snoms or Ciscos when the cloud is distant or better yet, solve basic 911 issues.

Only few cloud providers get this concept and the better ones have designed the “home” box to be interdependent where the phones still “phone-home” in its absence provided an internet connection is still present; failover in absence of the failover so-to-speak.

I will tell you that I am living through this right now and as the senior voice technologist I am leading the effort to take our 12,000+ station enterprise into VoIP. I just cutover my 1st site about 200 stations right before Christmas as a precursor to a pure VoIP install in a 640,000 square foot building that will open in March of 2012.

I agree that TDM is on the decline but the future for voice technologists will be up to the individual and their organization. What I’ve discovered here is that the Network infrastructure team doesn’t really want to be in the phone business and this has created a partnership between our teams.

The Network team is managing the data network backbone out to the PoE switches.

My team manages:

  • Endpoint deployments & monitoring/forensics
  • Business analysis (to match features with department workflow)
  • Station provisioning
  • System provisioning, maintenance and routing.
  • Edge devices like ATA’s (still require cross wire) and Gateways (for localized trunking and survivability).

You want to remember that endpoints still fail and still need to be deployed and users must be trained on how to use these new tools. I am piloting ALL the self service capabilities that my platform offers (and there’s a lot). However, some people want to take advantage of this and some don’t.

So I tell them use what you want and remember that the Help Desk and field techs are still available to you. Some people were even stressing out about this and you have to remind them that this new device does a lot more than your old phone but if the bells and whistles don’t impress you or even intimidate you just remember it’s still just a phone if that’s how you choose to use it.

  • There are soft-phone clients for desktops and wireless devices like PDA’s, i-Phones, i-Pads and other Smart-phone devices.
  • There are remote workers that need endpoint support.
  • Yesterday I just made my first video call through our new platform and this is just another example of another end-point solution that will need support.

In our enterprise phone replacements and moves still require a technician. As a matter of network security we use “port security” to keep people from moving their PC’s and other end-points.

Internet Security

If you move your device without telling the network team you will be very disappointed because your MAC address is locked to the switch port. So a move or change must be tightly coordinated between the field techs and network team. Also, how many companies patch every jack to a switch port? I know we don’t.

The one thing I have been stressing to my team is that there is plenty of work for everyone. Our new platform runs on two IBM Blade Centers and I explained to my team that they are just going to watch that hardware get installed and will not likely ever touch it.

If we have a hardware issue IBM will come in and resolve it. But as someone already said their job will morph to an application role. I was even astounded by the amount of Hardware that we are maintaining today in the TDM environment as compared to the two microwave size chassis that will accommodate 30,000 stations. So even though there’s a lot less hardware there is a lot more application.

Final Thoughts

The debate over the relevance of Time Division Multiplexing (TDM) highlights the ongoing evolution in telecommunications. While its traditional role may diminish with the emergence of newer technologies, TDM’s fate ultimately depends on its ability to adapt to changing industry dynamics and consumer demands.

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