Four Reasons Why VoIP is a Good Call

A strange thing has been happening to business telephony over the past decade: All the people you need or want to speak to have turned into voicemail. Sometimes when they get your message and call you back, you’ve turned into voice mail as well. This wastes a huge amount of time—and is, I believe, one of the main drivers of the “presence” capability that started in instant messaging (IM) and will soon be spreading to a unified communications platform near you.

Here are a few data points and thoughts, then we’ll get to the lessons:

Because circuit-switched telephony is thoroughly instrumented and standardized, you can pull a lot of data off of a Class 5 switch (the engine at the center of most large business phone—PABX or PBX—systems). When I was looking at the viability of changing over to VoIP a couple of years ago, I had the team that supported our telephone system in the U.S. pull a year’s worth of call detail records (CDR) from the switches and analyze them for various patterns of use. We had about 9,000 people and 6,000 physical extensions on the system, spread over a dozen switches – plenty of data to work with.

Here are some the findings.

  • We were making a lot of calls and spending a lot of money doing so.
  • About 65 percent of call attempts were to a “station” (not an 800 number) which we took to be a specific person. About 35 percent were to toll-free numbers and most of these (32 percent of all calls) were to audio bridge access numbers.
  • The 30 percent of bridged audio calls accounted for more than 60 percent of all minutes on the switch, and the percentage of minutes was steadily increasing.
  • 82 percent of all station-to-station calls ended up in voicemail. (And it didn’t matter if the call was station-to-station on our network or to an off-network number. The percentages were almost identical.)
  • The average number of attempts before a person–to-person connection was achieved was 3.15.
  • The average message left in voicemail lasted 28 seconds. (We had a 120 second maximum limit.)
  • Around 12 percent of the calls were to another country (mostly Canada, the U.K. or France with the remainder scattered all over Europe, Asia-Pacific and South America). There is voicemail everywhere these days and international voicemail is expensive.

    Remember that this data is from a global systems integrator (Capgemini), based on a highly mobile, highly dispersed workforce, so you might (almost certainly will) see a different pattern in your own calling record, assuming you ever look.

    I also looked more deeply at the use of bridged audio conferencing services (which we outsourced to a service provider). First surprise was that the number of bridge minutes had been rising about 24 percent per year for the past five years, even as the cost per minute had been declining. In 2004, we had consumed more than 36 million bridged minutes—more than 4,000 minutes per employee. Secondly, the number of calls was increasing faster than the total number of minutes used (but only a little). Thirdly, the average number of participants on a call was between 3 and 4, and was not rising, even as the median number of participants was. Fourthly, the average call duration was 51 minutes and was declining slightly over time.

    Let’s pause here for minute and look inside these numbers.

    In a distributed business, you run the company on the phone (even more than via IM and e-mail). That means lots of person-to-person calls, and lots of 30- to 60-minute group calls every week for the various management, sales and delivery teams. So a lot of those bridged minutes are “internal” calls that substitute for face-to-face meetings—about 69 percent, as it turns out, including company-wide calls as an adjunct to webcasts every month that generally had several hundred to a couple of thousand participants for about 30 minutes on average. Because we were an aggressive “hotelling” organization (with few permanently assigned offices or workspaces), people tended to call in individually even if they were actually only a few doors or cubes apart.

    Usage of bridged minutes is hugely asymmetric. The top 200 users consumed roughly 12 million minutes—about 20 hours a week of conference calls on average. The top 1,000 users of bridged minutes consumed more than 20 million minutes of the total. Shifting all those “already on net” minutes onto our existing WAN was a big part of the cost savings that underwrote the VoIP program.

    A lot of the off-net calls were from employees’ cell phones, meaning that we were paying for the minutes twice (we had a cell phone reimbursement program in which we gave employees access to a huge pool of very cheap minutes if they participated in the program). I never quite managed to count how much double payment went on (analyzing cell phone usage is more complex because we did not get all of the CDRs in digital form and had to pay the carriers in our program to analyze them in the detail we needed), but it looked like a lot. Even with very cheap cell phone minutes, this is a waste that was getting worse as more cell-phone-only behavior surfaced.

    So what can we learn from all this?

    Story Guide:

  • Four Reasons Why VoIP is a Good Call
  • Lesson One: Person-to-person calling attempts waste a lot of time.
  • Lesson Two: Scheduled audio conference calls are growing.
  • Lesson Three: Calls are not always the primary focus of attention.
  • Lesson Four: Consider a unified communications platform.

    Next page: Person-to-person calling attempts waste a lot of time.

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